Research ArticleAn Experimental Study of the Formation ofTalc through CaMg(CO3)2ndashSiO2ndashH2O Interaction at100ndash200∘C and Vapor-Saturation Pressures
Ye Wan1 Xiaolin Wang123 I-Ming Chou4 Wenxuan Hu12
Yang Zhang1 and Xiaoyu Wang1
1State Key Laboratory for Mineral Deposits Research School of Earth Sciences and Engineering Nanjing UniversityNanjing Jiangsu 210023 China2Institute of Energy Sciences Nanjing University Nanjing Jiangsu 210023 China3Shandong Provincial Key Laboratory of Depositional Mineralization and Sedimentary MineralsShandong University of Science and Technology Qingdao Shandong 266510 China4Laboratory of Experimental Study under Deep-Sea Extreme Conditions Institute of Deep-Sea Science and EngineeringChinese Academy of Sciences Sanya Hainan 572000 China
Correspondence should be addressed to Xiaolin Wang xlinwangnjueducn and Wenxuan Hu huwxnjueducn
Received 14 February 2017 Accepted 31 May 2017 Published 4 July 2017
Academic Editor Daniel E Harlov
Copyright copy 2017 Ye Wan et al This is an open access article distributed under the Creative Commons Attribution License whichpermits unrestricted use distribution and reproduction in any medium provided the original work is properly cited
Themetamorphic interaction between carbonate and silica-rich fluid is common in geological environmentsThe formation of talcfrom dolomite and silica-rich fluid occurs at low temperatures in the metamorphism of the CaOndashMgOndashSiO
2ndashCO2ndashH2O system
and plays important roles in the formation of economically viable talc deposits the modification of dolomite reservoirs and othergeological processes However disagreement remains over the conditions of talc formation at low temperatures In this study in situRaman spectroscopy quenched scanning electronmicroscopymicro-X-ray diffraction and thermodynamic calculationswere usedto explore the interplay between dolomite and silica-rich fluids at relatively low temperatures in fused silica tubes Results showedthat talc formed at le200∘C and low CO
2partial pressures (PCO
2) The reaction rate increased with increasing temperature and
decreased with increasing PCO2 The major contributions of this study are as follows (1) we confirmed the formation mechanism
of Mg-carbonate-hosted talc deposits and proved that talc can form at le200∘C (2) the presence of talc in carbonate reservoirs canindicate the activity of silica-rich hydrothermal fluids and (3) the reactivity and solubility of silica require further considerationwhen a fused silica tube is used as the reactor in high PndashT experiments
1 Introduction
The common metamorphic interaction between dolomiteand silica-rich fluids plays important roles inmany geologicalprocesses For example the interaction is closely associatedwith the formation of skarn ore deposits [1ndash3] Talc wasreported to format low temperatures in themetamorphismofthe CaOndashMgOndashSiO
2ndashH2OndashCO
2system [4ndash6] Talc is char-
acterized by a trioctahedron structure [7] and is chemicallyinert soft white and highly thermally conductive [8] Asa result talc is used in various industrial applications [79 10] Previous studies showed that talc mineralization canoccur in various geological settings such as the alteration
of ultra-mafic rocks (eg [11ndash15]) the mixing of seafloorhydrothermal fluids and seawater [16] and the alteration ofMg-carbonate rocks [17ndash21] However it is most economicalto extract from deposits associated with the hydrothermalalteration of dolostoneMg-carbonate [17]
Hydrothermal dolomite and hydrothermally altereddolomite are important hydrocarbon reservoirs (eg [22ndash25]) Geologically pervasive silica-rich hydrothermal fluidsderived from sources such as deep formation brines ormagma intrusions (eg [26ndash28]) can react with dolomiteto form talc in carbonate reservoirs influencing the reser-voirsrsquo physical properties [29ndash31] In addition talc has
HindawiGeofluidsVolume 2017 Article ID 3942826 14 pageshttpsdoiorg10115520173942826
2 Geofluids
a low friction coefficient so its formation along faults incarbonate rocks can promote the stable creep of a faultreleasing accumulated elastic strain and preventing strongearthquakes [32ndash35] Therefore thorough investigation ofthe CaMg(CO
3)2ndashSiO2ndashH2O interaction can help elucidate
many geological processesHowever disagreements remained regarding the for-
mation temperature of talc through the reaction betweendolomite and a silica-rich fluid The reaction has beentheoretically calculated to occur at ge150∘C [5 35 36] butmost geological studies have indicated that talc mainlyforms at 250ndash400∘C (eg [21 37 38]) For example inthe Saint-Barthelemy deposits in Switzerland oxygen iso-tope thermometric calculations showed that talc mineral-ization occurred at about 300∘C [21] which is consistentwith fluid inclusion data (250ndash300∘C) [39 40] Experimen-tal studies have sought to construct a phase diagram ofthe CaOndashMgOndashSiO
2ndashCO2ndashH2O system but hydrothermal
experimental studies have only been conducted above 250∘C(eg [4 41ndash44]) Consequently further experiments at lowertemperatures are necessary to fully explore the formationtemperature of talc
In this study the reactions for the CaMg(CO3)2ndash
SiO2ndashH2O system were conducted in fused silica tubes at
temperatures from 100 to 200∘C In situ Raman spectroscopywas used to characterize the vapor products The quenchedsolid products were investigated with Raman spectroscopyscanning electron microscopy (SEM) equipped with anenergy dispersive spectrometer (EDS) and micro-X-raydiffraction (micro-XRD) In addition the Gibbs free energyof the reaction was also calculated using the geochemicalmodelling program
2 Materials and Methods
21 Sample Preparation Dolomite powder was preparedfrom dolomite rocks of the Neoproterozoic Dengying For-mation in the Sichuan Basin Southwest China PowderXRD analyses showed that the dolomite rock is comprisedof gt97 dolomite and lt3 quartz Calcite grains wereprepared from colorless transparent rhombohedral calcitecrystals Distilled deionized water (182 KΩsdotcm) was usedthroughout Amorphous SiO
2originated from the fused silica
tubesChou et al [46] have reported detailed procedures for
constructing fused silica capillary capsules (FSCCs) Theprotective polyimide layer of the fused silica tube (05mm ininner diameter and 065mm in outer diameter) was burnt offin an oxyhydrogen flame and one end of the tube was sealedThe dolomitecalcite powder and a 05-cm longwater columnwere loaded into the tube and centrifuged to the sealed endThe open end was then connected to a pressure line Theair in the tube was evacuated and the open end of the tubewas sealed by fusion in the oxyhydrogen flame As shown inFigure 1 the prepared FSCC is about 2 cm long and consistsof the dolomite powder (sim05 cm in length) water (sim05 cmin length) and a vapor phase (sim1 cm in length)
High-pressure optical cells (HPOCs Figure 2(a)) con-taining dolomite andwater were also constructed for pressure
measurements The dolomite powder and deionized waterwere first loaded into a one-end-sealed fused silica tube(sim20 cm in length) Approximately 2 cm long mercury wasthen injected to separate the reaction system and the pressur-ization mediummdashwater The detailed procedures for prepar-ing HPOCs are described in Chou et al [47]
22 Experimental Procedures
221 In Situ Vapor-Phase Analyses The reaction betweendolomite and a silica-rich fluid to form talc involves decar-bonation of dolomite and the generation of CO2
3CaMg (CO3)2+ 4SiO
2+H2O
997888rarr Mg3(Si4O10) (OH)2 + 3CaCO3 + 3CO2
(1)
Raman spectroscopy is sensitive to CO2 and can detect CO2
at pressures lower than 06 bar [48 49] Therefore in situRaman spectroscopy of the vapor phasewas used to detect thereaction FSCCs containing dolomite and water were heatedin a heating stage (Linkam CAP500) calibrated with a K-typethermocouple which had been previously calibrated withthe triple point (0∘C) and boiling point (100∘C) of water at01MPa The temperature difference along the 4 cm centralline of the heating stage was less than 05∘C at 300∘C Thesetup of in situ Raman spectroscopic analysis is shown inFigure 1 The target temperature was increased at incrementsof 10∘C from an initial 60∘C until a CO
2signal was detected
in the vapor phase after heating for sim24 h To characterizethe mechanism of CO
2generation (metamorphic alteration
or decomposition of dissolved CO3
2minus) Raman spectra of thevapor phase within FSCCs containing calcite and water werealso acquired for comparison
Raman spectra were collected in situ for the vaporphase within FSCCs containing dolomite and water at 200∘C(higher than the reaction threshold) to investigate the kineticsof the reaction The experimental duration was increasedfrom 2 h to sim240 h
222 Pressure Measurements The setup for the pressuremeasurement is shown in Figure 2(a) The HPOC containingdolomite andwater was connected to a pressurization systemPressures were monitored by a Setra 206D digital pressuretransducer with Datum 2002 manometer (69MPa full scaleaccurate to plusmn014) The HPOC containing dolomite andwater was heated to 200∘C using a Linkam CAP 500 heatingstage The position of mercury in the HPOC was fixed byadjusting the pressure with a pressure generator and then thepressure of the whole systemwas recorded with experimentalduration (Figure 2(a))
223 Analyses of Solid Products Several one-end-open fusedsilica tubes containing dolomite and water were placed ina 10mL batch stainless steel reactor equipped with a Teflon(PTFE) internal cup (Figure 2(b)) The reactor was thenheated at 150 and 200∘C for 20ndash90 days in an oven witha temperature accuracy of plusmn5∘C During the reaction thereactor was opened and the product CO
2was released several
Geofluids 3
Heatingstage
DolomiteVapor phase
FSCC 4
H2O
Figure 1 Setup for in situ analyses of the vapor phase within a FSCCcontaining dolomite and water
times to promote the reaction After heatingmicro-XRD andRaman spectroscopy were used to characterize the compo-sition of the quenched solid product at room temperatureThen the SEM was used to observe the morphology ofthe product The chemical composition was analyzed usingEDS
23 Analytical Methods Raman spectra were collected witha high-resolution Raman spectrometer (LabRAM HR800JYHoriba) using a 53211 nm laser from an air-cooledfrequency-doubled NdYAG laser excitation a 50x objective(Olympus) and a 1800 groovemm grating with a spectralresolution of about 1 cmminus1 An approximate 95mW laser wasfocused on the central level of the horizontal tube for vaporspectra acquisition and on the surface of the solid phase forsolid spectra acquisition Spectra were collected from 100 to1600 cmminus1 To obtain a high signal-to-noise ratio spectrumthree accumulationswere collected in denoisemode (120 s forthe vapor phase and 30 s for the solid phase) and averaged foreach spectrum Before collection the Raman spectrometerwas calibrated with the V1 band of silicon at 5202 cmminus1[50] Labspec 5 software was used for Raman spectral analy-ses
Micro-XRD investigations of the quenched reacteddolomite were carried out with a diffractometer (DmaxRapid II Rigaku) equipped with a Mo tube and a 300-120583m diameter collimator The diffractometer was operatedat 50 kV and 90mA with an angular velocity of 6∘s andan exposure time of 15min Jade 6 software was used tocharacterize the compositions of the solid phase
The morphology of the quenched reacted dolomite wasobserved using a field emission (FE) SEM (Supra55 Zeiss)with an accelerating voltage of 15 kVThe approximate chem-ical composition of the solid phase was analyzed by an EDS(Oxford Instruments Inca X-Max 150mm2) All experimentswere performed at the Institute of Energy Sciences andthe State Key Laboratory for Mineral Deposits Researchhosted in School of Earth Sciences and Engineering NanjingUniversity
In addition we calculated the Gibbs free energy of talcformation from the CaMg(CO
3)2ndashSiO2(aq)ndashH
2O system for
the PndashT conditions covered in these experiments using theHch program (version 44) and its incorporated Unithermdatabase [51]
3 Results
31 Vapor-Phase Characterization The linear CO2 moleculehas four vibrational modes a symmetric stretching mode(V1) two bending modes (2V2 V2a and V2b) and an antisym-metric stretching mode (V3) (eg [48 52 53]) The modesV1 and 2V2 are both Raman active and have a similar energy(sim1335 cmminus1) and the same symmetry species resulting ina Fermi resonance [48] Fermi resonance causes the excitedadmixed states to split into two prominent peaks an upperband at sim1388 cmminus1 and a lower band at sim1285 cmminus1 [48 54]Weak hot bands flanking the Fermi diads may also appearin the spectrum [48] Raman spectroscopy has very lowdetection limits for CO
2and thus is used frequently for CO
2
characterization in fluid inclusions [53 55ndash58]Figure 3(a) shows the Raman spectra of the vapor phase
in FSCCs containing CaMg(CO3)2ndashH2O and CaCO
3ndashH2O
after heating at 90ndash150∘C for 24 h For the FSCCs containingdolomite and water no CO2 signal was observed afterheating at le90∘C Weak but clear CO2 Fermi bands at sim1285and 1384 cmminus1 were observed after heating at 100∘C TheRaman intensity of CO
2was much stronger after heating at
150∘C than that at 100∘C (Figure 3(a)) That is to say CO2
was generated in the CaMg(CO3)2ndashSiO2ndashH2O system when
heated at ge100∘C with an experimental duration of 24 hHowever the signals of CO
2were not observed in FSCCs
containing calcite and water after heating at 100ndash200∘C for24 h Considering that a greater concentration of CO
3
2minus
dissolved from calcite than from dolomite in pure waterat temperatures of 100ndash150∘C [59 60] we suggest that theCO2from the dolomite-bearing system was generated by
decarbonation via metamorphic reaction (1) instead of thedecomposition of dissolved CO3
2minusThe intensity and wavenumber of the CO2 Fermi diad
bands varywith changes in theCO2 pressure and temperature[48 53 56] Previous studies have suggested that the Fermidiad splits increase with increasing CO2 pressure at a con-stant temperature (eg [61]) Accordingly several equationswere constructed for quantitative measurements of the CO2density based on the Fermi diad splits by using referencesamples with PCO
2gt 06 bar ([49] and references therein)
In this study the Fermi diad peak positions and splits of CO2
produced from CaMg(CO3)2ndashSiO2ndashH2O interaction were
also obtained (Table 1) However negative density values wereobtained when applying these calibration curves to quanti-tatively measure the CO
2content in the FSCC This result
indicates that only a small amount of CO2was produced
in the FSCC and that the CO2pressure was lower than 06
bar Table 2 shows the variation of the internal pressure ofa HPOC containing dolomite and water with experimentalduration Results showed that the internal pressure fluctuatedwith reaction time Consequently the exact partial pressureof CO
2generated from the metamorphic reaction (1) cannot
be obtained this should also result from the very lowPCO2
The variation in the Raman intensity of CO2 as a functionof the experimental duration can reflect the kinetics of reac-tions yieldingCO2 [57] Increasing the experimental durationcould increase the CO2 intensity (Figure 3(b))The peak areas
4 Geofluids
Pres
sure
gen
erat
or
Pressure detector
Dolomite Vapor
Mercury
HPOC in heating stage
Simplified pressure line
H2O
H2O
(a) HPOC setup
RC
IC
CICOven
Dolom
ite
H2O
SCR
(b)
Figure 2 (a) The setup for measurements of the internal pressures within a HPOC containing dolomite and water (b) the batch stainlessreactor in the oven The left schematic diagram showing the structure of the reactor SCR represents the stainless cup of the reactor RCrepresents the reactor cover IC represents internal cup and CIC represents cover of the internal cup
Upper band
Lower band
Ram
an in
tens
ity (a
u)
1250 1300 1350 14001200 1450
CO2
150∘C 24 h
100∘C 24 h
90∘C 24 h
100∘C 24 h
Raman shift (cmminus1)
CaMg(CO3)2ndashSiO2ndashH2O
CaMg(CO3)2ndashSiO2ndashH2O
CaMg(CO3)2ndashSiO2ndashH2O
CaCO3ndashSiO2ndashH2O
(a)
Upper band
Lower band
Hot band
24 h
1200 1250 1300 1350 1400 1450
41 h
8 h
2 h
200∘C
Ram
an in
tens
ity (a
u)
Raman shift (cmminus1)
(b)
Figure 3 Raman spectra of the vapor phase in FSCCs containing (a) CaCO3ndashH2O and CaMg(CO
3)2ndashH2O after heating at 90ndash150∘C for 24 h
and (b) CaMg(CO3)2ndashH2O after heating at 200∘C from 2 to 41 h
of the CO2Fermi diad bands increased with experimental
duration up to about 120 h (200∘C) before eventually levelingoff (Figure 4 Table 1) Solid-phase characterization (seeSection 32) indicated that the dolomite was unlikely torun out over the length of the experiment Consequentlythe reaction reached an equilibrium state after reaction forsim120 hThe degree of the reaction (R) can be calculated using
the ratio between the total Raman peak area of CO2at time t
(A) and that at equilibrium state (119860lowast)
119877 () = 119860119860lowasttimes 100 (2)
As shown in Figure 4 (diamonds) the slope of R decreaseswith the increase of reaction time indicating that the
Geofluids 5
Table 1 Fermi diad bands splits and peak areas of CO2generated in the FSCC containing dolomite and water at 200∘C and the calculated
degree of reaction
Reaction time (h) Fermi diads and splits (cmminus1) Peak area Degree of reaction ()aV1
V2
Δ V1
V2
V1+ V2
0 mdash mdash mdash 0 0 0 02 128521 138792 10271 31587 36662 68249 1584 128519 138777 10258 53083 77521 130604 3026 128509 13877 10261 55164 81714 136878 3168 128514 138772 10258 59966 955 155466 35910 128484 138749 10265 73141 102321 175462 40620 128551 138804 10253 90065 141902 231967 53622 128545 1388 10255 100018 148336 248354 57428 128537 138795 10258 115519 171856 287375 66440 128543 138798 10255 13279 191084 323874 74843 128566 138821 10255 127099 188707 315806 73046 128576 138823 10247 138806 19958 338386 78249 128563 138817 10254 134642 192119 326761 75560 128539 138794 10255 13706 216374 353434 81765 128562 138816 10254 143307 220862 364169 84270 128559 138814 10255 145465 217231 362696 83887 128501 138757 10256 156179 230784 386963 89492 128549 138793 10244 162326 228882 391208 904104 128573 138811 10238 17136 245737 417097 964137 128567 138804 10237 172976 258905 431881149 128526 138799 10273 174657 250163 42482159 128538 138797 10259 183627 255395 439022171 128531 138793 10262 179781 259946 439727193 128524 138777 10253 169712 268104 437816203 128537 138795 10258 17552 255508 431028213 128566 138821 10255 174085 254889 428974224 12856 138815 10255 1725 25597 42847aThe total Raman peak area of CO2 at equilibrium state is an average of those after reaction for sim120 h Then the degree of reaction can be regarded as 100when the reaction time exceeds 120 h
reaction rates decrease with the increase of experimentaldurationPCO
2 The results also showed that the reaction
rate increased with increasing temperature For example theRaman intensity of CO2 was stronger at higher temperaturewithin a given period of time (Figure 3(a))
32 Solid-Phase Characterization Figure 5 shows XRD pat-terns of the quenched solid relicts in the fused silica tubesAfter heating at 200∘C for sim20 days the talc signals wereweak However heating for 80 days produced calcite andtalc as the main phases in the solid relicts whereas dolomitesignals were hardly visible in the XRD pattern (Figure 5)
The Raman spectrum of the solid phase before heat-ing (Figure 6) showed only dolomite peaks (sim177 30051098 cmminus1 [62]) indicating that the dolostone was of highpurity consistent with the XRD analysis However in addi-tion to dolomite characteristic calcite signals (sim282 and1086 cmminus1 [63]) and talc signals (1905 3605 and 675 cmminus1[64]) appeared after heating at 200∘C for 60 days
Figure 7 shows the morphology of the solid phaseafter heating at 200∘C for 60 days The solid phase has ahoneycomb-like texture and was widely distributed in therelicts (Figures 7(a)ndash7(d)) It was identified by EDS as talc(Figure 7(c)) The talc exhibited unoriented textures becauseit formed under strain-free conditions [21] Some cylindri-cal talc also occurred along the inner surface of the FSCC(Figure 7(d)) The dolomite grains had smooth edges (Fig-ure 7(c)) indicating dissolution during heating Some prod-ucts of rhombohedral calcite (Figure 7(d)) were also presentin the solid phase which formed along with the talc via reac-tion (1)
The amount of Mg-silicate mineral produced at 150∘Cfor 40 days was below the detection limit of the micro-XRD equipment Only dolomite and a small amount ofcalcite were observed in the XRD pattern after heating at150∘C for 40 days (Figure 5) This further supports the viewthat the metamorphic reaction rate is largely dependent ontemperature Some researchers view talc as the initial meta-morphic mineral for the CaMg(CO
3)2ndashSiO2ndashH2O system
6 Geofluids
TotalDegree of reaction
0
1000
2000
3000
4000
5000
Peak
area
0
20
40
60
80
100
Deg
ree o
f rea
ctio
n (
)
40 80 120 160 200 2400Reaction time (h)
sim1285minus1
simminus1
cmcm1385
Figure 4 Raman peak areas of CO2and the degree of reaction
versus reaction time at 200∘CBlack rectangles and red circles denotethe peak areas of the lower band at sim1285 cmminus1 and the upper bandat sim1385 cmminus1 respectively Blue triangles represent the total peakareas of both bandsThe green diamonds represent the degree of thereaction Data plotted are from Table 1
971
55 384
71
302
763
1645
283
81 258
822
4894
227
84
209
05 191
20
171
96
186
99
161
981
6004 1
5216
147
07 143
701
4219
133
691
3102
129
561
2440
123
451
1777
115
181
1437
402
133
6891
266
44
288
26
253
162
3986
219
03
201
262
0639
184
751
7863
156
49 154
19
138
75
110
89
104
471
0602
TalcCalciteDolomite
452
10
10 15 20 25 30 35 4052 (∘)Mo tube
20 days
40 days150∘C
200∘C
80 days200∘C
Figure 5 X-ray patterns of the solid relicts in FSCCs containingdolomite and water after heating at 150∘C for sim40 days (lower blueline) and at 200∘C for sim20 days (middle orange line) and sim80 days(upper black line)
(eg [4ndash6]) However serpentine minerals like lizardite andchrysotile are also likely to form at low temperatures duringmetamorphism of the CaOndashMgOndashSiO
2ndashH2OndashCO
2system
especially in contact or regional metamorphic settings [65ndash67] Some researchers have even pointed out that serpentineforms at lower temperatures than talc during metamorphism
CalciteDolomite
TalcRam
an in
tens
ity (a
u)
Solid phase
400 600 800 1000 1200200Raman shift (cmminus1)
(200∘C 60 days)
Figure 6 Raman spectrum of solid relicts after heating at 200∘C for60 daysThe reference spectra of dolomite calcite and talc were alsoshown for comparison The dolomite spectrum was acquired fromthe sample before heating The calcite spectrum was acquired fromcrystalline calcite and the reference spectrum of talc was cited froman open database hosted by the Department of Geosciences at theUniversity of Arizona (RRUFF Project httprruffinfoindexphp)
Table 2 Variations in the internal pressures of the HPOC contain-ing dolomite and water with experimental duration at 200∘C
serpentine is likely to form in a low-silica environment
Geofluids 7
(a) (b)
MgOSi
Dol
(c)
Talc
CaO
C
(d)
Figure 7 SEM micrographs and EDS analyses of the solid relicts in an FSCC containing dolomite and water after heating at 200∘C for sim60days (a b) Honeycomb-like talc (c) dolomite grains with smooth edges and EDS result of talc (yellow arrow) (d) euhedral calcite formed inthe relicts (white arrow) and cylindrical talc growing on the inner surface of the tube (yellow arrow)
further introduction of SiO2 will make talc stable relativeto serpentine [70ndash73] Considering the fact that talc wascharacterized as the product of Mg-silicate mineral in the200∘C experiment via reaction (1) we speculate that whilenot detected byXRD talc also formed below 200∘C sinceCO
2
was generated during the experiment (see above)
33 Thermodynamic Calculations Due to the limits of theUnithermdatabase we used aqueous silica as the SiO
2species
that participated in the reaction Considering that the solu-bility of amorphous silica was high at elevated temperatures[74] the calculated results should approximate the conditionsof the experiments The Gibbs free energy (Δ119866) of formationfor talc from CaMg(CO3)2 aqueous SiO2 and H
2O at the
pressure and temperature of interest are given in Table 3 TheΔ119866 of reaction decreases with increasing temperature at thesaturation pressure This indicates that the reaction is morefavorable at higher temperatures The Δ119866 becomes negativeat 119879 ge 80∘C which implies that the formation of product talcfrom dolomite and a silica-rich fluid is thermodynamicallyfavored However this reaction may not commence untileven higher temperatures are reached due to the probableinitial kinetic barrier to the reaction These thermodynamiccalculations support the implication from the experimentalresults that talc formation can occur at temperatures above100∘C
4 Discussion
41 Implications for the Formation of Mg-Carbonate-HostedTalc Geologically Prochaska [18] grouped the talc depositsinto five types (1) talc related to ultramafics (eg [13ndash15]) (2)Mg-carbonate-hosted talc (eg [20 37]) (3) metamorphictalc (eg [75 76]) (4) talc related to banded iron forma-tions (mostly minnesotaite [77 78]) and (5) secondary talcdeposits [18] The most economically viable of these depositsare usually related to the metamorphic reaction between anMg-carbonate infiltrated by a silica-rich hydrothermal fluid[18 20 21 37] Intense fractures that increase the permeabilityof geological fluid flow generally develop near such deposits[18 20 21 37 38]
Investigating the formation temperature of talc canimprove our understanding of its mineralization processThis has previously been done using several methods Theseinclude microthermometric measurements of relevant fluidinclusions (eg [39 40 79]) and calculations using talcndashdolo-mite oxygen isotope thermometry assuming that themineralpairs achieve oxygen isotope equilibrium [21 36] In additionthe phase diagram of the CaOndashMgOndashSiO2ndashCO2ndashH2O sys-tem has often been referred to for evaluating the formationtemperature of talc [5 35] The diagram was establishedbased on hydrothermal experiments geological case studiesand thermodynamic calculations [4 5 43 44] However the
8 Geofluids
Table 3 The Gibbs free energies of the reaction 3CaMg(CO3)2+ 4SiO
2(aq) + H
2O = Mg
3(Si4O10)(OH)
2+ 3CaCO
3+ 3CO
2at the
temperatures of interest and their corresponding saturation pressures
Temperature (∘C) Δ119866a (kJmol) 119875satb (bar) Temperature (∘C) ΔG (kJmol) 119875sat (bar)
25 7709 0032 100 ndash7083 101450 4663 0124 110 ndash9951 143460 2771 0199 120 ndash12938 198770 0609 0312 130 ndash16032 270380 ndash1778 0474 140 ndash19223 361590 ndash4351 0702 150 ndash22502 4761aΔ119866 refers to the Gibbs free energy of the reaction b119875sat represents the corresponding saturation pressures which are calculated based on the thermodynamicmodel proposed by Zhang and Duan [45]
experiments used to chart out this systemhave been generallyconducted at gt250∘C [4 41ndash44] The reaction path of thephase diagram at low temperatures was mainly establishedthrough thermodynamic calculations implying the need fortalc forming experiments at temperatures below 250∘C
Some geological case studies attribute low talc mineral-ization temperatures (lt200∘C) derived from adjacent talc anddolomite oxygen isotope thermometry to actually reflect iso-topic disequilibrium [36] This study shows that talc depositscan still form at temperatures below 200∘C on geologicaltime scales especially if the product CO
2can be released
(cf reaction (1)) However large-scale talc mineralization ismore likely to form at higher temperatures (eg 250ndash400∘C)Firstly PCO
2controls the lower thermal limit of talc stability
The onset temperature of the transformation increases withincreasing PCO
2 because CO
2is a product of the metamor-
phic reaction (1) and its presence greatly decreases the solu-bility of SiO
2in the fluid [80] CO
2is a common component
in geological fluids and can be either released from magmas(eg [81ndash84]) or generated from the hydrothermal alterationof carbonate (eg [85ndash87]) The oxidation (eg [88]) andhydrothermal maturation of organic matter are also naturalsources of CO
2[89 90]Therefore talcmineralization should
occur at relatively high temperatures in the presence of CO2
Secondly as our results have shown the reaction rate forreaction (1) increases sharply with increasing temperaturefacilitating talc deposits to form at higher temperatures
This study can also contribute to understanding the faultweakening mechanism in the upper crust The elastic strainaccumulation along a fault can be released through a suddenseismic slip (earthquake) or aseismic creep slip [32] A lowerfrictional coefficient for a fault will facilitate stable creepweakening the fault and suppressing the occurrence of strongearthquakes [35]The frictional coefficient of a fault generallydecreases with increasing temperature [35] Therefore faultsare likely to beweakened due to high temperatures in the deepcrust but not in the cool shallow crust The pervasive distri-bution of clay minerals along faults has also been thought toweaken faults [33ndash35 91ndash94] because layered clay mineralsexhibit much lower frictional coefficients than otherminerals[95] For example talc discovered along the SanAndreas faultzone is responsible for helping in aiding slippage along thefault [35 95] As shown here dolomite could react at le200∘Cwith silica-rich fluids traveling along fault planes to form
talc and hence might be an important mechanism of faultweakening in carbonate sequences in the upper crust
42 Implications for Hydrothermal Dolomite Reservoir Re-search Carbonate rock is the main type of hydrocarbonreservoir worldwide hosting over 60 of petroleum reserves[31] Dolomite hydrocarbon reservoirs are important com-prising about half of the carbonate hydrocarbon reser-voirs worldwide [96] Recent research has suggested thathydrothermal alteration can increase the porosity and per-meability of dolomite reservoirs substantially and is animportant factor affecting the development and distributionof dolomite reservoirs [24 25 97ndash101] The Tarim basin isone of the most important petroliferous basins in China andcontains a lower Palaeozoic carbonate series which is alsoan important hydrocarbon reservoir Recent exploration hasshown that silica-rich hydrothermal fluids have infiltratedthese carbonate series improving the physical properties ofthe reservoirs considerably (eg the Shunnan area of theTarim Basin [102 103]) It has been proposed that silica-richhydrothermal fluids were transported through extensionalfaults from the deep strata to the shallow carbonate sequencewhere they migrated laterally through porous and permeablecarbonate formations (sim6670m in the Shunnan area [104])Hydrothermal fluids originating in deep basins are generallyhot Microthermometric measurements have indicated thatthe silica-rich hydrothermal fluids in the Tarim basin reachover 200∘C [101 103] Given that the lower part of the lowerPalaeozoic sequence is mainly composed of dolomite silica-rich hydrothermal fluids could react with the dolomite toform talc and thus change the physical properties of the reser-voir Recently petrologic and diagenetic research haverevealed pervasive silicification in Early Cretaceous ultra-deep water carbonate reservoirs in the Atlantic Ocean off-shore from Brazil [105] The presence of talc calcite quartzand dolomite on the thin-section scale may indicate that thedolomite was strongly corroded by a silica-rich hydrothermalfluid
Alteration of dolomite to talcwill alsomodify the porosityand permeability of carbonate hydrocarbon reservoirs [29ndash31] The silica required for the mineral alteration can be pro-vided by either silica-rich hydrothermal fluids or silica (egquartz chert and opal) within the carbonate reservoirs [106]If SiO
2derives from quartzchert in the dolomite sequences
Geofluids 9
the hydrothermal alteration would increase the porosity ofthe dolomite reservoirs McKinley et al [29] reported thatthe total volume of minerals within a dolomite reservoir canbe reduced by 13 to 17 through the reaction betweendolomite and quartz in reaction (1) In addition the reactionbetween dolomite and silica-rich hydrothermal fluids can actas an important source of CO
2 in hydrocarbon reservoirsThepresence of CO2 can lower the pH of the formation waterand thus promote the dissolution of carbonate minerals [60107 108] increasing the porosity of the reservoirs [109ndash111]However the pore throats may be blocked by the formationof talc or other clay minerals [29 112] Therefore moredetailed factors should be considered in order to unequi-vocally evaluate the effects of silica-rich hydrothermal fluidsin dolomite reservoirs
Although talc can form from the interaction betweendolomite and silica-rich fluids at low temperatures it isseldom observed in hydrocarbon reservoirs [29 31] for thefollowing two reasons (1)A large amount of CO
2can be pro-
duced by the maturation of organic matter and the reactionbetween carbonate minerals and organic acid [98 101] Thepresence of CO
2decreases the lower thermal stability field
of talc [113] (2)The reaction path is dependent on the com-position of the hydrothermal fluid For example K+ andAl3+ are also important components of geological fluidsMontmorillonite instead of talc is more likely to form inthe presence of only a small quantity of Al3+ [41] and theformation of talc can also be inhibited by K+ [29]
43 Implications for High PndashT Experiment Using Fused SilicaCapillary Tubes as Reactors FSCCs are used to constructsynthetic fluid inclusions containing organic and inorganiccomponents [46] They offer advantages such as being inertto many components especially acids and S allowing forthe convenient synthesis of fluid inclusions and facilitatingin situ optical and Raman spectroscopic observations (eg[57 114ndash117]) Fused silica tubes can tolerate relatively hightemperatures up to 600∘C and pressures up to 300MPa As aresult FSCCs are used in many research fields For examplein addition to construction of synthetic fluid inclusions[46 53 118] FSCCs were used in studying the propertiesof hydrothermal fluids as optical and Raman spectroscopiccells [115ndash117 119ndash121] FSCCs were also used as reactorsin investigating the mechanism of thermochemical sulfatereduction [114] and the decomposition of organic matter[57]
However SiO2 in the FSCC acted as a reagent in thisstudy and was partially dissolved as indicated by the pitson the inner surface of the tube (Figures 8(a)ndash8(d)) Thedissolution of silica from FSCCs containing alkali sulfatesolutions was also observed after quenching from ge350∘C(Figures 8(e) and 8(f)) The severe dissolution of fused silicacan be ascribed to three factors (1) Amorphous silica ismore soluble than quartz especially at high temperaturesIn neutral solutions its solubility increases sharply withtemperature from 100 ppm at 20∘C to 1500 ppm at 310∘C[74 122 123] (2) Under basic conditions the solubility ofamorphous silica is greatly enhanced by the ionization ofsilicic acid (H
4SiO4+ OHminus rarr H
3SiO4
minus + H2O [124]) (3)
SiO2may act as a reagent as it did in this experiment The
presence of dissolution pits will weaken the mechanicalstrength of the silica tube In addition the presence ofdissolved silica can make the system more complicated thanexpected Therefore the solubility and reactivity of silicaunder hydrothermal conditions should be evaluated beforeFSCCs are used as reactors
5 Conclusion
The reactions in the CaMg(CO3)2ndashSiO2ndashH2O system atlow temperatures were investigated using fused silica tubesas reactors Results showed that dolomite reacted with asilica-rich fluid to form talc calcite and CO2 at le200
∘Cand low PCO2 The reaction rate increased with increasingtemperature and decreased with rising PCO2Therefore hightemperature and the presence of a conduit to release CO2 willpromote the formation of talcThis experiment has importantgeological and geochemical implications(1)Theresults confirmed themechanism of talcminerali-
zation in Mg-carbonate hosted talc deposits Dolomitereacted with silica-rich hydrothermal fluids to form talccalcite and CO
2 Talc could form at le200∘C whereas pre-
vious hydrothermal experiments examining the CaOndashMgOndashSiO2ndashCO2ndashH2O system were mainly conducted at gt250∘C
However considering the effect of temperature on thereaction rate and other geological conditions massive talcdeposits are still more likely to form at higher temperaturesThe formation of talc along a fault in a Mg-carbonateformation will also weaken the fault thus preventing strongearthquakes(2) Talc in carbonate reservoirs can indicate the activity
of silica-rich hydrothermal fluids Fluid-aided alteration ofdolomite can change the physical properties of dolomitereservoirs substantially The reaction between dolomite andquartz within the carbonate can decrease the total volume ofminerals by 13ndash17 The generation of CO2 can promotethe dissolution of carbonate minerals elsewhere under theappropriate conditions increasing the porosity and perme-ability of carbonate reservoirs However talc minerals mayblock pore throats in the reservoirs Therefore additionalfactors need to be considered when evaluating the effectsof CaMg(CO
3)2ndashSiO2ndashH2O interactions on the physical
properties of carbonate reservoirs(3) The solubility and reactivity of silica should be con-
sidered when using fused silica tubes as reactors in highPndashT experiments The dissolution of silica will increase thecomplexity of the system andweaken themechanical strengthof the tube
Conflicts of Interest
The authors declare that they have no conflicts of interest
Acknowledgments
The dolomite sample was provided by Mr Chunhua ShiMisses Yang Qu Wanlu Gao and Ye Qiu helped the authorsa lot during the micro-XRD analysis and HPOC experiment
10 Geofluids
Outer surfaceInner surface
(a) (b)In
ner s
urfa
ce
(c) (d)
Inner surface
(e) (f)
Figure 8 SEM images of the inner surface of the silica tube (a) Smooth inner surface before the reaction (b) magnification of the squarearea shown in (a) (c) dissolution pits on the inner surface after heating at 200∘C for sim60 days (d) magnification of (c) severe erosion of thesilica on the inner surface of FSCCs containing (e) 10m Na
2SO4and (f) 10m Li
2SO4after heating at 350∘C for 1 h
Dr Rui Wang and Miss Siyu Hu are also thanked for theirhelp in the thermodynamic calculations of the reactionsThis work was financially supported by the National NaturalScience Foundation of China (Grant nos 41230312 and41573054) I-Ming Chou is thankful for the support of theKnowledge Innovation Program (SIDSSE-201302) and theHadal-trench Research Program (XDB06060100) of ChineseAcademy of Sciences
References
[1] L D Meinert ldquoSkarns and skarn depositsrdquo Geoscience Canadavol 19 no 4 pp 145ndash162 1992
[2] L D Meinert G M Dipple and S Nicolescu ldquoWorld skarndepositsrdquo Economic Geology 100th Anniversary Volume pp299ndash336 2005
[3] Y Yao J Chen J Lu R Wang and R Zhang ldquoGeology andgenesis of the Hehuaping magnesian skarn-type cassiterite-sulfide deposit Hunan Province Southern ChinardquoOre GeologyReviews vol 58 no C pp 163ndash184 2014
[4] T M Gordon and H J Greenwood ldquoThe reaction dolomite+ quartz + water = talc + calcite + carbon dioxiderdquo AmericanJournal of Science vol 268 pp 225ndash242 1970
[5] M B Holness ldquoFluid flow paths and mechanisms of fluidinfiltration in carbonates during contact metamorphism TheBeinn an Dubhaich aureole Skyerdquo Journal of MetamorphicGeology vol 15 no 1 pp 59ndash70 1997
Geofluids 11
[6] W Heinrich S S Churakov andM Gottschalk ldquoMineral-fluidequilibria in the system CaOndashMgOndashSiO
2ndashH2OndashCO
2ndashNaCl
and the record of reactive fluid flow in contact metamorphicaureolesrdquo Contributions to Mineralogy and Petrology vol 148no 2 pp 131ndash149 2004
[7] M Wesołowski ldquoThermal decomposition of talc a reviewrdquoThermochimica Acta vol 78 no 1-3 pp 395ndash421 1984
[8] L A Perez-Maqueda A Duran and J L Perez-RodrıguezldquoPreparation of submicron talc particles by sonicationrdquoAppliedClay Science vol 28 no 1-4 pp 245ndash255 2005
[9] R L Johnson ldquoTalcrdquoAmerican Ceramic Society Bulletin vol 71pp 818ndash820 1992
[10] R L Johnson and R L Virta ldquoTalcrdquo American Ceramic SocietyBulletin vol 79 pp 79ndash81 2000
[11] M Z Abzalov ldquoChrome-spinels in gabbro-wehrlite intrusionsof the Pechenga area Kola Peninsula Russia emphasis onalteration featuresrdquo Lithos vol 43 no 3 pp 109ndash134 1998
[12] M F El-Sharkawy ldquoTalc mineralization of ultramafic affinity inthe Eastern Desert of Egyptrdquo Mineralium Deposita vol 35 no4 pp 346ndash363 2000
[13] M Franceschelli G Carcangiu A M Caredda G CrucianiI Memmi and M Zucca ldquoTransformation of cumulate maficrocks to granulite and re-equilibration in amphibolite andgreenschist facies in NE Sardinia Italyrdquo Lithos vol 63 no 1-2pp 1ndash18 2002
[14] S G Tesalina P Nimis T Auge and V V Zaykov ldquoOriginof chromite in mafic-ultramafic-hosted hydrothermal massivesulfides from the Main Uralian Fault South Urals RussiardquoLithos vol 70 no 1-2 pp 39ndash59 2003
[15] D M Evans ldquoMetamorphic modifications of the Muremeramafic-ultramafic intrusions eastern Burundi and their effecton chromite compositionsrdquo Journal of African Earth Sciencesvol 101 pp 19ndash34 2015
[16] T Yamanaka K Maeto H Akashi et al ldquoShallow submarinehydrothermal activity with significant contribution of mag-matic water producing talc chimneys in the Wakamiko CraterofKagoshimaBay southernKyushu Japanrdquo Journal of Volcanol-ogy and Geothermal Research vol 258 pp 74ndash84 2013
[17] B Moine J P Fortune P Moreau and F Viguier ldquoComparativemineralogy geochemistry and conditions of formation of twometasomatic talc and chlorite deposits Trimouns PyreneesFrance and Rabenwald eastern Alps Austriardquo Economic Geol-ogy vol 84 no 5 pp 1398ndash1416 1989
[18] W Prochaska ldquoGeochemistry and genesis of Austrian talcdepositsrdquo Applied Geochemistry vol 4 no 5 pp 511ndash525 1989
[19] P de Parseval S Jiang F Fontan R Wang F Martin and JFreeet ldquoGeology and ore genesis of the Trimouns talc-chloriteore deposit Pyrenees Francerdquo Acta Petrologica Sinica vol 20no 4 pp 877ndash886 2004
[20] A C Gondim and S Jiang ldquoGeologic characteristics and gene-ticmodels for the talc deposits in Parana andBahia BrazilrdquoActaPetrologica Sinica vol 20 no 4 pp 829ndash836 2004
[21] P Boulvais P de Parseval A DrsquoHulst and P Paris ldquoCarbonatealteration associated with talc-chlorite mineralization in theeastern Pyrenees with emphasis on the St Barthelemy MassifrdquoMineralogy and Petrology vol 88 no 3-4 pp 499ndash526 2006
[22] G R Davies and L B Smith Jr ldquoStructurally controlled hydro-thermal dolomite reservoir facies an overviewrdquoAAPG Bulletinvol 90 no 11 pp 1641ndash1690 2006
[23] J Lonnee and H G Machel ldquoPervasive dolomitization withsubsequent hydrothermal alteration in theClarke Lake gas field
Middle Devonian Slave Point Formation British ColumbiaCanadardquo AAPG Bulletin vol 90 no 11 pp 1739ndash1761 2006
[24] J A Luczaj ldquoEvidence against the Dorag (mixing-zone) modelfor dolomitization along theWisconsin arch - A case for hydro-thermal diagenesisrdquo AAPG Bulletin vol 90 no 11 pp 1719ndash1738 2006
[25] L B Smith Jr ldquoOrigin and reservoir characteristics of UpperOrdovician Trenton-Black River hydrothermal dolomite reser-voirs in New YorkrdquoAAPG Bulletin vol 90 no 11 pp 1691ndash17182006
[26] J Parnell ldquoDevonianMagadi-type cherts in theOrcadian BasinScotlandrdquo Journal of Sedimentary Petrology vol 56 no 4 pp495ndash500 1986
[27] J M Garcıa-Ruiz ldquoCarbonate precipitation into alkaline silica-rich environmentsrdquo Geology vol 26 no 9 pp 843ndash846 1998
[28] J Zhang W Hu Y Qian et al ldquoFormation of saddle dolomitesin Upper Cambrian carbonates western Tarim Basin (north-west China) implications for fault-related fluid flowrdquo Marineand Petroleum Geology vol 26 no 8 pp 1428ndash1440 2009
[29] J M McKinley R H Worden and A H Ruffell ldquoContactdiagenesis the effect of an intrusion on reservoir quality in thetriassic sherwood sandstone group Northern Irelandrdquo Journalof Sedimentary Research vol 71 no 3 pp 484ndash495 2001
[30] S Dong D Chen H Qing et al ldquoHydrothermal alteration ofdolostones in the Lower Ordovician Tarim Basin NW Chinamultiple constraints from petrology isotope geochemistry andfluid inclusion microthermometryrdquo Marine and PetroleumGeology vol 46 pp 270ndash286 2013
[31] V Madrucci C W D D Anjos R A Spadini D B Alvesand S M C Anjos ldquoAuthigenic magnesian clays in carbonatereservoirs in Brazilrdquo in Proceedings of the 15th International ClayConference Rio De Janeiro Brazil 2013
[32] C H Scholz ldquoEarthquakes and friction lawsrdquo Nature vol 391no 6662 pp 37ndash42 1998
[33] A M Schleicher B A Van Der Pluijm J G Solum andL N Warr ldquoOrigin and significance of clay-coated fracturesin mudrock fragments of the SAFOD borehole (ParkfieldCalifornia)rdquoGeophysical Research Letters vol 33 no 16 ArticleID L16313 2006
[34] A M Schleicher B A van der Pluijm and L N Warr ldquoNano-coatings of clay and creep of the San Andreas fault at ParkfieldCaliforniardquo Geology vol 38 no 7 pp 667ndash670 2010
[35] C Collettini C Viti S A F Smith and R E HoldsworthldquoDevelopment of interconnected talc networks and weakeningof continental low-angle normal faultsrdquo Geology vol 37 no 6pp 567ndash570 2009
[36] F Tornos and B F Spiro ldquoThe geology and isotope geochem-istry of the talc deposits of Puebla de Lillo (Cantabrian zonenorthern Spain)rdquo Economic Geology vol 95 no 6 pp 1277ndash1296 2000
[37] L Hecht R Freiberger H A Gilg G Grundmann and Y AKostitsyn ldquoRare earth element and isotope (C O Sr) charac-teristics of hydrothermal carbonates genetic implications fordolomite-hosted talc mineralization at Gopfersgrun (Fichtelge-birge Germany)rdquo Chemical Geology vol 155 no 1-2 pp 115ndash130 1999
[38] R Sharma P Joshi and P D Pant ldquoThe role of fluids inthe formation of talc deposits of Rema area Kumaun LesserHimalayardquo Journal of the Geological Society of India vol 73 no2 pp 237ndash248 2009
12 Geofluids
[39] P De Parseval B Moine J P Fortune and J Ferret ldquoFluid-mineral interactions at the origin of the Trimouns talc andchlorite deposit (Pyrenees France)rdquo in Current Research inGeology Applied to Ore Deposits P Fenoll Hach-Ali J Torrez-Ruiz and F Gervilla Eds pp 205ndash209 University of GranadaGranada Granada Spain 1993
[40] M C Boiron P Boulvais M Cathelineau D Banks N Cal-vayrac and G Hubert ldquoFluid circulation at the origin of thetrimouns talc deposit (Pyrenees France)rdquo in Proceedings of the18th Meeting of European Current Research on Fluid InclusionsSiena Italy 2005
[41] P Bayliss andA A Levhinson ldquoLow temperature hydrothermalsynthesis from dolomite or calcite quartz and kaoliniterdquo Claysand Clay Minerals vol 19 no 2 pp 109ndash114 1971
[42] G Skippen ldquoAn experimental model for low pressure meta-morphism of siliceous dolomitic marblerdquo American Journal ofScience vol 274 no 5 pp 487ndash509 1974
[43] J Slaughter D M Kerrick and V J Wall ldquoExperimen-tal and thermodynamic study of equilibria in the systemCaOndashMgOndashSiO
2ndashH2OndashCO
2rdquoAmerican Journal of Science vol
275 pp 143ndash162 1975[44] R G Eggert and D M Kerrick ldquoMetamorphic equilibria in the
siliceous dolomite system 6 kbar experimental data and geo-logic implicationsrdquo Geochimica et Cosmochimica Acta vol 45no 7 pp 1039ndash1049 1981
[45] Z Zhang and Z Duan ldquoPrediction of the PVT properties ofwater over wide range of temperatures and pressures frommolecular dynamics simulationrdquo Physics of the Earth andPlanetary Interiors vol 149 no 3-4 pp 335ndash354 2005
[46] I-M Chou Y Song and R C Burruss ldquoA newmethod for syn-thesizing fluid inclusions in fused silica capillaries containingorganic and inorganic materialrdquo Geochimica et CosmochimicaActa vol 72 no 21 pp 5217ndash5231 2008
[47] I-M Chou R C Burruss and W J Lu ldquoA new optical cellfor spectroscopic studies of geologic fluids at pressures up to100MPardquo in Advances in High-Pressure Technology for Geo-physical Applications J Chen YWang T S Duffy G Shen andL F Dobrzhinetakaya Eds pp 475ndash485 Elsevier AmsterdamNetherlands 2005
[48] K M Rosso and R J Bodnar ldquoMicrothermometric and Ramanspectroscopic detection limits of CO
2in fluid inclusions and the
Raman spectroscopic characterization of CO2rdquo Geochimica et
Cosmochimica Acta vol 59 no 19 pp 3961ndash3975 1995[49] H M Lamadrid Geochemistry of fluid-rock processes [Doctoral
dissertation] Virginia Polytechnic Institute and State Univer-sity Blacksburg VA USA 2016
[50] J H Parker D W Feldman and M Ashkin ldquoRaman scatteringby silicon and germaniumrdquo Physical Review vol 155 no 3 pp712ndash714 1967
[51] Y V Shvarov ldquoAlgorithmization of the numeric equilibriummodeling of dynamic geochemical processesrdquo GeochemistryInternational vol 37 no 6 pp 571ndash576 1999
[52] R B Wright and C H Wang ldquoDensity effect on the Fermiresonance in gaseous CO
2by Raman scatteringrdquoThe Journal of
Chemical Physics vol 58 no 7 pp 2893ndash2895 1973[53] XWang I-M ChouWHu R C Burruss Q Sun and Y Song
ldquoRaman spectroscopic measurements of CO2density experi-
mental calibration with high-pressure optical cell (HPOC) andfused silica capillary capsule (FSCC) with application to fluidinclusion observationsrdquo Geochimica et Cosmochimica Acta vol75 no 14 pp 4080ndash4093 2011
[54] H R Gordon and T K McCubbin Jr ldquoThe 28-micron bandsof CO
2rdquo Journal of Molecular Spectroscopy vol 19 no 1ndash4 pp
137ndash154 1966[55] T Azbej M J Severs B G Rusk and R J Bodnar ldquoIn situ
quantitative analysis of individual H2O-CO
2fluid inclusions by
laser Raman spectroscopyrdquo Chemical Geology vol 237 no 3-4pp 255ndash263 2007
[56] Y Song I M Chou W Hu B Robert and W Lu ldquoCO2
density-raman shift relation derived from synthetic inclusionsin fused silica capillaries and its applicationrdquo Acta GeologicaSinica (English Edition) vol 83 pp 932ndash938 2009
[57] Z Pan I-M Chou and R C Burruss ldquoHydrolysis of polycar-bonate in sub-critical water in fused silica capillary reactor within situ Raman spectroscopyrdquo Green Chemistry vol 11 no 8 pp1105ndash1107 2009
[58] M L Frezzotti F Tecce and A Casagli ldquoRaman spectroscopyfor fluid inclusion analysisrdquo Journal of Geochemical Explorationvol 112 pp 1ndash20 2012
[59] E L Shock and H C Helgeson ldquoCalculation of the thermo-dynamic and transport properties of aqueous species at highpressures and temperatures correlation algorithms for ionicspecies and equation of state predictions to 5 kb and 1000∘CrdquoGeochimica et Cosmochimica Acta vol 52 no 8 pp 2009ndash20361988
[60] O S Pokrovsky SVGolubev J Schott andACastillo ldquoCalcitedolomite and magnesite dissolution kinetics in aqueous solu-tions at acid to circumneutral pH 25 to 150∘C and 1 to 55 atmpCO2 New constraints on CO
2sequestration in sedimentary
basinsrdquo Chemical Geology vol 265 no 1-2 pp 20ndash32 2009[61] YGarrabos R Tufeu B LeNeindre G Zalczer andD Beysens
ldquoRayleigh andRaman scattering near the critical point of carbondioxiderdquo The Journal of Chemical Physics vol 72 no 8 pp4637ndash4651 1979
[62] J H Nicola J F Scott R M Couto andMM Correa ldquoRamanspectra of dolomite [CaMg(CO
3)2]rdquo Physical Review B vol 14
no 10 pp 4676ndash4678 1976[63] S Gunasekaran G Anbalagan and S Pandi ldquoRaman and
infrared spectra of carbonates of calcite structurerdquo Journal ofRaman Spectroscopy vol 37 no 9 pp 892ndash899 2006
[64] G J Rosasco and J J Blaha ldquoRaman microprobe spectra andvibrationalmode assignments of talcrdquoApplied Spectroscopy vol34 no 2 pp 140ndash144 1980
[65] V Trommsdorff and B W Evans ldquoAntigorite-ophicarbo-nates phase relations in a portion of the system CaOndashMgOndashSiO2ndashH2OndashCO
2rdquo Contributions to Mineralogy and Petrology
vol 60 no 1 pp 39ndash56 1977[66] V Trommsdorff and J A D Connolly ldquoConstraints on phase
diagram topology for the systemCaOndashMgOndashSiO2ndashCO2ndashH2Ordquo
Contributions to Mineralogy and Petrology vol 104 no 1 pp 1ndash7 1990
[67] B S Van Gosen H A Lowers S J Sutley and C A GentldquoUsing the geologic setting of talc deposits as an indicator ofamphibole asbestos contentrdquo Environmental Geology vol 45no 7 pp 920ndash939 2004
[68] W Johannes ldquoAn experimental investigation of the systemMgO-SiO
2-H2O-CO
2rdquo American Journal of Science vol 267
no 9 pp 1083ndash1104 1969[69] E S Schandl and M P Gorton ldquoHydrothermal alteration and
CO2metasomatism (natural carbon sequestration) of komati-
ites in the south-western Abitibi greenstone beltrdquo CanadianMineralogist vol 50 no 1 pp 129ndash146 2012
Geofluids 13
[70] B W Evans and S Guggenheim ldquoTalc phyrophyllite andrelated mineralsrdquo in Reviews in Mineralogy S W Bailey Edvol 19 pp 225ndash294 1988
[71] B Velde ldquoExperimental pseudomorphism of diopside by talcand serpentine in (Ni Mg)Cl
2aqueous solutionsrdquo Geochimica
et Cosmochimica Acta vol 52 no 2 pp 415ndash424 1988[72] A E Williams-Jones C Normand H Clark Vali Jr R F
Martin A Dufresne and Nayebzadeh A ldquoControls of amphi-bole formation in chrysotile from the Jeffrey Mine AsbestosQuebecrdquo inTheHealth Effects Effects of Chrysotile Asbestos R PNolan AM LangerM RossWicks F J andMartin F R Edsvol 5 pp 89ndash104 The Mineralogical Association of CanadaQuebec Quebec Canada 2001
[73] B W Evans ldquoThe serpentinite multisystem revisited chrysotileis metastablerdquo International Geology Review vol 46 no 6 pp479ndash506 2004
[74] I Gunnarsson and S Arnorsson ldquoAmorphous silica solubilityand the thermodynamic properties of H
4SiO∘4in the range of
0∘ to 350∘C at Psatrdquo Geochimica et Cosmochimica Acta vol 64no 13 pp 2295ndash2307 2000
[75] M W Bodine Jr ldquoTrioctahedral clay mineral assemblages inPaleozoic marine evaporite rocksrdquo in Proceedings of the Pre-sented in the Sixth International Symposium on Salt vol 1 pp267ndash284 Toronto Canada 1983
[76] W Schreyer and K Abraham ldquoThree-stage metamorphic his-tory of a whiteschist from Sar e Sang Afghanistan as part ofa former evaporite depositrdquo Contributions to Mineralogy andPetrology vol 59 no 2 pp 111ndash130 1976
[77] T Angerer and S G Hagemann ldquoThe BIF-hosted high-gradeiron ore deposits in the archean koolyanobbing greenstonebelt Western Australia structural control on synorogenic-and weathering-related magnetite- hematite- and goethite-rich iron orerdquo Economic Geology vol 105 no 5 pp 917ndash9452010
[78] P Duuring and S Hagemann ldquoLeaching of silica bands andconcentration of magnetite in Archean BIF by hypogene fluidsBeebyn Fe ore deposit Yilgarn Craton Western AustraliardquoMineralium Deposita vol 48 no 3 pp 341ndash370 2013
[79] D Shin and I Lee ldquoFluid inclusions and their stable isotopegeochemistry of the carbonate-hosted talc deposits near theCretaceous Muamsa Granite South Koreardquo Geochemical Jour-nal vol 40 no 1 pp 69ndash85 2006
[80] P G Novgorodov ldquoSolubility of quartz in anH2OndashCO
2mixture
at 700 degrees C and pressures of 3 and 5 kbarsrdquoGeokhimiya pp1484ndash1489 1975
[81] T M Gerlach ldquoChemical characteristics of the volcanic gasesfrom Nyiragongo lava lake and the generation of CH
4-rich
fluid inclusions in alkaline rocksrdquo Journal of Volcanology ampGeothermal Research vol 8 no 2-4 pp 177ndash189 1980
[82] J V Walther and P M Orville ldquoVolatile production and trans-port in regional metamorphismrdquo Contributions to Mineralogyand Petrology vol 79 no 3 pp 252ndash257 1982
[83] W F Giggenbach ldquoThe origin and evolution of fluids inmagmatic-hydrothermal systemsrdquo in Geochemistry of Hydro-thermalOreDeposits H L Barnes Ed pp 737ndash796WileyNewYork NY USA 3 edition 1997
[84] J B Lowenstern ldquoCarbon dioxide in magmas and implicationsfor hydrothermal systemsrdquoMineralium Deposita vol 36 no 6pp 490ndash502 2001
[85] R Kerrich and W S Fyfe ldquoThe gold-carbonate associationsource of CO
2 and CO
2fixation reactions in Archaean lode
depositsrdquo Chemical Geology vol 33 no 1ndash4 pp 265ndash294 1981
[86] P I Nabelek ldquoCalc-silicate reactions and bedding-controlledisotopic exchange in the Notch Peak aureole Utah implicationsfor differential fluid fluxes with metamorphic graderdquo Journal ofMetamorphic Geology vol 20 no 4 pp 429ndash440 2002
[87] P I Nabelek ldquoFluid evolution and kinetics of metamorphicreactions in calc-silicate contact aureoles - From H
2O to CO
2
and backrdquo Geology vol 35 no 10 pp 927ndash930 2007[88] H G Machel ldquoBacterial and thermochemical sulfate reduction
in diagenetic settings - old and new insightsrdquo SedimentaryGeology vol 140 no 1-2 pp 143ndash175 2001
[89] L Stalker P Farrimond and S R Larter ldquoWater as an oxygensource for the production of oxygenated compounds (includingCO2precursors) during kerogen maturationrdquo Organic Geo-
chemistry vol 22 no 3-5 pp 477ndashIN4 1994[90] Z K Shipton J P Evans D Kirschner P T Kolesar A P
Williams and J Heath ldquoAnalysis of CO2leakage through lsquolow-
permeabilityrsquo faults from natural reservoirs in the ColoradoPlateau east-central Utahrdquo Geological Society Special Publica-tion vol 233 pp 43ndash58 2004
[91] J Byerlee ldquoFriction overpressure and fault normal compres-sionrdquo Geophysical Research Letters vol 17 no 12 pp 2109ndash21121990
[92] C Morrow B Radney and J Byerlee ldquoChapter 3 frictionalstrength and the effective pressure law of montmorillonite andlllite claysrdquo International Geophysics vol 51 no C pp 69ndash881992
[93] C A Morrow D E Moore and D A Lockner ldquoThe effectof mineral bond strength and adsorbed water on fault gougefrictional strengthrdquo Geophysical Research Letters vol 27 no 6pp 815ndash818 2000
[94] D A Lockner C Morrow D Moore and S Hickman ldquoLowstrength of deep San Andreas fault gouge from SAFOD corerdquoNature vol 472 no 7341 pp 82ndash86 2011
[95] D EMoore andM J Rymer ldquoTalc-bearing serpentinite and thecreeping section of the San Andreas faultrdquo Nature vol 448 no7155 pp 795ndash797 2007
[96] DH Zenger ldquoDiscussion lsquoOn the formation and occurrence ofsaddle dolomitersquordquo Journal of Sedimentary Petrology vol 51 no4 pp 1350ndash1352 1981
[97] DAKatzG P Eberli P K Swart andL B Smith Jr ldquoTectonic-hydrothermal brecciation associated with calcite precipitationand permeability destruction in Mississippian carbonate reser-voirs Montana and Wyomingrdquo AAPG Bulletin vol 90 no 11pp 1803ndash1841 2006
[98] M Esteban and C Taberner ldquoSecondary porosity developmentduring late burial in carbonate reservoirs as a result of mixingandor cooling of brinesrdquo Journal of Geochemical Explorationvol 78-79 pp 355ndash359 2003
[99] H G MacHel ldquoInvestigations of burial diagenesis in carbonatehydrocarbon reservoir rocksrdquoGeoscience Canada vol 32 no 3pp 103ndash128 2005
[100] J A Sagan and B S Hart ldquoThree-dimensional seismic-baseddefinition of fault-related porosity development Trenton-BlackRiver interval Saybrook Ohiordquo AAPG Bulletin vol 90 no 11pp 1763ndash1785 2006
[101] F Xing and S Li ldquoGenesis and environment characteristics ofdolomite-hosted quartz and its significance for hydrocarbonexploration in Keping Area Tarim Basin Chinardquo Journal ofEarth Science vol 23 no 4 pp 476ndash489 2012
[102] L Yun and Z Cao ldquoHydrocarbon enrichment pattern andexploration potential of the Ordovician in Shunnan area TarimBasinrdquo Oil and Gas Geology vol 35 no 6 pp 788ndash797 2014
14 Geofluids
[103] Y Li N Ye X Yuan Q Huang B Su and R Zhou ldquoGeologicaland geochemical characteristics of silicified hydrothermal fluidsin Well Shunnan 4 Tarim Basinrdquo Oil and Gas Geology vol 36no 6 pp 934ndash944 2015
[104] L Qi ldquoOil and gas breakthrough in ultra-deep Ordoviciancarbonate formations in Shuntuoguole uplift Tarim BasinrdquoChina Petroleum Exploration vol 21 no 3 pp 38ndash51 2016 (inChinese with English abstract)
[105] H R Qing ldquoAn introduction of petrology and diagenesis ofultra-deep water carbonate reservoirs from the Atlantic Oceanoffshore Brazilrdquo 2017 Oral presentation at Wuxi Institute ofPetroleum Geology of SINOPEC Wuxi China
[106] G J Simandl and S Paradisl ldquoCarbonate-hosted talcrdquo SelectedBritish ColumbiaMineral Deposit Profiles vol 3 pp 35ndash38 1999
[107] Y K Kharaka D R Cole S D Hovorka W D Gunter K GKnauss and BM Freifeld ldquoGas-water-rock interactions in FrioFormation following CO
2injection implications for the storage
of greenhouse gases in sedimentary basinsrdquoGeology vol 34 no7 pp 577ndash580 2006
[108] Z Duan and D Li ldquoCoupled phase and aqueous speciesequilibrium of the H
2OndashCO
2ndashNaClndashCaCO
3system from 0 to
250∘C 1 to 1000 bar with NaCl concentrations up to saturationof haliterdquo Geochimica et Cosmochimica Acta vol 72 no 20 pp5128ndash5145 2008
[109] M R Giles and J DMarshall ldquoConstraints on the developmentof secondary porosity in the subsurface re-evaluation of pro-cessesrdquoMarine and PetroleumGeology vol 3 no 3 pp 243ndash2551986
[110] O S Pokrovsky S V Golubev and J Schott ldquoDissolution kinet-ics of calcite dolomite and magnesite at 25∘C and 0 to 50 atmpCO2rdquo Chemical Geology vol 217 no 3-4 pp 239ndash255 2005
[111] P Cao Z T Karpyn and L Li ldquoThe role of host rock pro-perties in determining potential CO
2migration pathwaysrdquo
International Journal of Greenhouse Gas Control vol 45 pp 18ndash26 2016
[112] M D Fishburn ldquoSignificant results of deep drilling at ElkHills Kern County Californiardquo in Structure Stratigraphy andHydrocarbon Occurrences of the San Joaquin Basin CaliforniaG K Kuespert and S A Reid Eds vol 64 pp 157ndash167 PacificSections Society of Economic Paleontologists and Mineralo-gists and American Association of Petroleum Geologists 1990
[113] E Povoden M Horacek and R Abart ldquoContact metamor-phism of siliceous dolomite and impure limestones from theWerfen formation in the eastern Monzoni contact aureolerdquoMineralogy and Petrology vol 76 no 1-2 pp 99ndash120 2002
[114] S Yuan I-M Chou R C Burruss X Wang and J Li ldquoDispro-portionation and thermochemical sulfate reduction reactions inSndashH2OndashCH
4and SndashD
2OndashCH
4systems from 200 to 340∘C at
elevated pressuresrdquo Geochimica et Cosmochimica Acta vol 118pp 263ndash275 2013
[115] X Wang I-M Chou W Hu and R C Burruss ldquoIn situ obser-vations of liquid-liquid phase separation in aqueous MgSO
4
solutions geological and geochemical implicationsrdquo Geochim-ica et Cosmochimica Acta vol 103 pp 1ndash10 2013
[116] X Wang Y Wan W Hu et al ldquoIn situ observations of liquid-liquid phase separation in aqueous ZnSO
4solutions at tem-
peratures up to 400∘C Implications for Zn2+ndashSO2minus4
[117] X Wang IM Chou W Hu Y Wan and Z Li ldquoPropertiesof lithium under hydrothermal conditions revealed by in situ
Raman spectroscopic characterization of Li2O-SO
3-H2O(D2O)
systems at temperatures up to 420∘Crdquo Chemical Geology vol451 pp 104ndash115 2017
[118] L Shang I-M Chou W Lu R C Burruss and Y ZhangldquoDetermination of diffusion coefficients of hydrogen in fusedsilica between 296 and 523 K by Raman spectroscopy and appli-cation of fused silica capillaries in studying redox reactionsrdquoGeochimica et CosmochimicaActa vol 73 no 18 pp 5435ndash54432009
[119] M Dargent J Dubessy L Truche E F Bazarkina C Nguyen-Trung and P Robert ldquoExperimental study of uranyl(VI) chlo-ride complex formation in acidic LiCl aqueous solutions underhydrothermal conditions (T = 21∘Cndash350∘C Psat) using Ramanspectroscopyrdquo European Journal ofMineralogy vol 25 no 5 pp765ndash775 2013
[120] YWanXWangWHu and I-MChou ldquoRaman spectroscopicobservations of the ion association between Mg2+ and SO2minus
4
in MgSO4-saturated droplets at temperatures of le380∘Crdquo The
Journal of Physical Chemistry A vol 119 no 34 pp 9027ndash90362015
[121] Y Wan X Wang W Hu I M Chou Y Chen and Z Xu ldquoInsitu optical and Raman spectroscopic observations of the effectsof pressure and fluid composition on liquidliquid phase separa-tion in aqueous cadmium sulfate solutions (=400∘C 50MPa)with geological and geochemical implicationsrdquo Geochimica etCosmochimica Acta vol 211 pp 133ndash152 2017
[122] W L Marshall ldquoAmorphous silica solubilitiesmdashI Behavior inaqueous sodium nitrate solutions 25ndash300∘C 0ndash6 molalrdquo Geo-chimica et Cosmochimica Acta vol 44 no 7 pp 907ndash913 1980
[123] C-T A Chen andW LMarshall ldquoAmorphous silica solubilitiesIV Behavior in pure water and aqueous sodium chloridesodium sulfate magnesium chloride and magnesium sulfatesolutions up to 350∘Crdquo Geochimica et Cosmochimica Acta vol46 no 2 pp 279ndash287 1982
[124] B A Fleming and D A Crerar ldquoSilicic acid ionization and cal-culation of silica solubility at elevated temperature and pHapplication to geothermal fluid processing and reinjectionrdquoGeothermics vol 11 no 1 pp 15ndash29 1982
a low friction coefficient so its formation along faults incarbonate rocks can promote the stable creep of a faultreleasing accumulated elastic strain and preventing strongearthquakes [32ndash35] Therefore thorough investigation ofthe CaMg(CO
3)2ndashSiO2ndashH2O interaction can help elucidate
many geological processesHowever disagreements remained regarding the for-
mation temperature of talc through the reaction betweendolomite and a silica-rich fluid The reaction has beentheoretically calculated to occur at ge150∘C [5 35 36] butmost geological studies have indicated that talc mainlyforms at 250ndash400∘C (eg [21 37 38]) For example inthe Saint-Barthelemy deposits in Switzerland oxygen iso-tope thermometric calculations showed that talc mineral-ization occurred at about 300∘C [21] which is consistentwith fluid inclusion data (250ndash300∘C) [39 40] Experimen-tal studies have sought to construct a phase diagram ofthe CaOndashMgOndashSiO
2ndashCO2ndashH2O system but hydrothermal
experimental studies have only been conducted above 250∘C(eg [4 41ndash44]) Consequently further experiments at lowertemperatures are necessary to fully explore the formationtemperature of talc
In this study the reactions for the CaMg(CO3)2ndash
SiO2ndashH2O system were conducted in fused silica tubes at
temperatures from 100 to 200∘C In situ Raman spectroscopywas used to characterize the vapor products The quenchedsolid products were investigated with Raman spectroscopyscanning electron microscopy (SEM) equipped with anenergy dispersive spectrometer (EDS) and micro-X-raydiffraction (micro-XRD) In addition the Gibbs free energyof the reaction was also calculated using the geochemicalmodelling program
2 Materials and Methods
21 Sample Preparation Dolomite powder was preparedfrom dolomite rocks of the Neoproterozoic Dengying For-mation in the Sichuan Basin Southwest China PowderXRD analyses showed that the dolomite rock is comprisedof gt97 dolomite and lt3 quartz Calcite grains wereprepared from colorless transparent rhombohedral calcitecrystals Distilled deionized water (182 KΩsdotcm) was usedthroughout Amorphous SiO
2originated from the fused silica
tubesChou et al [46] have reported detailed procedures for
constructing fused silica capillary capsules (FSCCs) Theprotective polyimide layer of the fused silica tube (05mm ininner diameter and 065mm in outer diameter) was burnt offin an oxyhydrogen flame and one end of the tube was sealedThe dolomitecalcite powder and a 05-cm longwater columnwere loaded into the tube and centrifuged to the sealed endThe open end was then connected to a pressure line Theair in the tube was evacuated and the open end of the tubewas sealed by fusion in the oxyhydrogen flame As shown inFigure 1 the prepared FSCC is about 2 cm long and consistsof the dolomite powder (sim05 cm in length) water (sim05 cmin length) and a vapor phase (sim1 cm in length)
High-pressure optical cells (HPOCs Figure 2(a)) con-taining dolomite andwater were also constructed for pressure
measurements The dolomite powder and deionized waterwere first loaded into a one-end-sealed fused silica tube(sim20 cm in length) Approximately 2 cm long mercury wasthen injected to separate the reaction system and the pressur-ization mediummdashwater The detailed procedures for prepar-ing HPOCs are described in Chou et al [47]
22 Experimental Procedures
221 In Situ Vapor-Phase Analyses The reaction betweendolomite and a silica-rich fluid to form talc involves decar-bonation of dolomite and the generation of CO2
3CaMg (CO3)2+ 4SiO
2+H2O
997888rarr Mg3(Si4O10) (OH)2 + 3CaCO3 + 3CO2
(1)
Raman spectroscopy is sensitive to CO2 and can detect CO2
at pressures lower than 06 bar [48 49] Therefore in situRaman spectroscopy of the vapor phasewas used to detect thereaction FSCCs containing dolomite and water were heatedin a heating stage (Linkam CAP500) calibrated with a K-typethermocouple which had been previously calibrated withthe triple point (0∘C) and boiling point (100∘C) of water at01MPa The temperature difference along the 4 cm centralline of the heating stage was less than 05∘C at 300∘C Thesetup of in situ Raman spectroscopic analysis is shown inFigure 1 The target temperature was increased at incrementsof 10∘C from an initial 60∘C until a CO
2signal was detected
in the vapor phase after heating for sim24 h To characterizethe mechanism of CO
2generation (metamorphic alteration
or decomposition of dissolved CO3
2minus) Raman spectra of thevapor phase within FSCCs containing calcite and water werealso acquired for comparison
Raman spectra were collected in situ for the vaporphase within FSCCs containing dolomite and water at 200∘C(higher than the reaction threshold) to investigate the kineticsof the reaction The experimental duration was increasedfrom 2 h to sim240 h
222 Pressure Measurements The setup for the pressuremeasurement is shown in Figure 2(a) The HPOC containingdolomite andwater was connected to a pressurization systemPressures were monitored by a Setra 206D digital pressuretransducer with Datum 2002 manometer (69MPa full scaleaccurate to plusmn014) The HPOC containing dolomite andwater was heated to 200∘C using a Linkam CAP 500 heatingstage The position of mercury in the HPOC was fixed byadjusting the pressure with a pressure generator and then thepressure of the whole systemwas recorded with experimentalduration (Figure 2(a))
223 Analyses of Solid Products Several one-end-open fusedsilica tubes containing dolomite and water were placed ina 10mL batch stainless steel reactor equipped with a Teflon(PTFE) internal cup (Figure 2(b)) The reactor was thenheated at 150 and 200∘C for 20ndash90 days in an oven witha temperature accuracy of plusmn5∘C During the reaction thereactor was opened and the product CO
2was released several
Geofluids 3
Heatingstage
DolomiteVapor phase
FSCC 4
H2O
Figure 1 Setup for in situ analyses of the vapor phase within a FSCCcontaining dolomite and water
times to promote the reaction After heatingmicro-XRD andRaman spectroscopy were used to characterize the compo-sition of the quenched solid product at room temperatureThen the SEM was used to observe the morphology ofthe product The chemical composition was analyzed usingEDS
23 Analytical Methods Raman spectra were collected witha high-resolution Raman spectrometer (LabRAM HR800JYHoriba) using a 53211 nm laser from an air-cooledfrequency-doubled NdYAG laser excitation a 50x objective(Olympus) and a 1800 groovemm grating with a spectralresolution of about 1 cmminus1 An approximate 95mW laser wasfocused on the central level of the horizontal tube for vaporspectra acquisition and on the surface of the solid phase forsolid spectra acquisition Spectra were collected from 100 to1600 cmminus1 To obtain a high signal-to-noise ratio spectrumthree accumulationswere collected in denoisemode (120 s forthe vapor phase and 30 s for the solid phase) and averaged foreach spectrum Before collection the Raman spectrometerwas calibrated with the V1 band of silicon at 5202 cmminus1[50] Labspec 5 software was used for Raman spectral analy-ses
Micro-XRD investigations of the quenched reacteddolomite were carried out with a diffractometer (DmaxRapid II Rigaku) equipped with a Mo tube and a 300-120583m diameter collimator The diffractometer was operatedat 50 kV and 90mA with an angular velocity of 6∘s andan exposure time of 15min Jade 6 software was used tocharacterize the compositions of the solid phase
The morphology of the quenched reacted dolomite wasobserved using a field emission (FE) SEM (Supra55 Zeiss)with an accelerating voltage of 15 kVThe approximate chem-ical composition of the solid phase was analyzed by an EDS(Oxford Instruments Inca X-Max 150mm2) All experimentswere performed at the Institute of Energy Sciences andthe State Key Laboratory for Mineral Deposits Researchhosted in School of Earth Sciences and Engineering NanjingUniversity
In addition we calculated the Gibbs free energy of talcformation from the CaMg(CO
3)2ndashSiO2(aq)ndashH
2O system for
the PndashT conditions covered in these experiments using theHch program (version 44) and its incorporated Unithermdatabase [51]
3 Results
31 Vapor-Phase Characterization The linear CO2 moleculehas four vibrational modes a symmetric stretching mode(V1) two bending modes (2V2 V2a and V2b) and an antisym-metric stretching mode (V3) (eg [48 52 53]) The modesV1 and 2V2 are both Raman active and have a similar energy(sim1335 cmminus1) and the same symmetry species resulting ina Fermi resonance [48] Fermi resonance causes the excitedadmixed states to split into two prominent peaks an upperband at sim1388 cmminus1 and a lower band at sim1285 cmminus1 [48 54]Weak hot bands flanking the Fermi diads may also appearin the spectrum [48] Raman spectroscopy has very lowdetection limits for CO
2and thus is used frequently for CO
2
characterization in fluid inclusions [53 55ndash58]Figure 3(a) shows the Raman spectra of the vapor phase
in FSCCs containing CaMg(CO3)2ndashH2O and CaCO
3ndashH2O
after heating at 90ndash150∘C for 24 h For the FSCCs containingdolomite and water no CO2 signal was observed afterheating at le90∘C Weak but clear CO2 Fermi bands at sim1285and 1384 cmminus1 were observed after heating at 100∘C TheRaman intensity of CO
2was much stronger after heating at
150∘C than that at 100∘C (Figure 3(a)) That is to say CO2
was generated in the CaMg(CO3)2ndashSiO2ndashH2O system when
heated at ge100∘C with an experimental duration of 24 hHowever the signals of CO
2were not observed in FSCCs
containing calcite and water after heating at 100ndash200∘C for24 h Considering that a greater concentration of CO
3
2minus
dissolved from calcite than from dolomite in pure waterat temperatures of 100ndash150∘C [59 60] we suggest that theCO2from the dolomite-bearing system was generated by
decarbonation via metamorphic reaction (1) instead of thedecomposition of dissolved CO3
2minusThe intensity and wavenumber of the CO2 Fermi diad
bands varywith changes in theCO2 pressure and temperature[48 53 56] Previous studies have suggested that the Fermidiad splits increase with increasing CO2 pressure at a con-stant temperature (eg [61]) Accordingly several equationswere constructed for quantitative measurements of the CO2density based on the Fermi diad splits by using referencesamples with PCO
2gt 06 bar ([49] and references therein)
In this study the Fermi diad peak positions and splits of CO2
produced from CaMg(CO3)2ndashSiO2ndashH2O interaction were
also obtained (Table 1) However negative density values wereobtained when applying these calibration curves to quanti-tatively measure the CO
2content in the FSCC This result
indicates that only a small amount of CO2was produced
in the FSCC and that the CO2pressure was lower than 06
bar Table 2 shows the variation of the internal pressure ofa HPOC containing dolomite and water with experimentalduration Results showed that the internal pressure fluctuatedwith reaction time Consequently the exact partial pressureof CO
2generated from the metamorphic reaction (1) cannot
be obtained this should also result from the very lowPCO2
The variation in the Raman intensity of CO2 as a functionof the experimental duration can reflect the kinetics of reac-tions yieldingCO2 [57] Increasing the experimental durationcould increase the CO2 intensity (Figure 3(b))The peak areas
4 Geofluids
Pres
sure
gen
erat
or
Pressure detector
Dolomite Vapor
Mercury
HPOC in heating stage
Simplified pressure line
H2O
H2O
(a) HPOC setup
RC
IC
CICOven
Dolom
ite
H2O
SCR
(b)
Figure 2 (a) The setup for measurements of the internal pressures within a HPOC containing dolomite and water (b) the batch stainlessreactor in the oven The left schematic diagram showing the structure of the reactor SCR represents the stainless cup of the reactor RCrepresents the reactor cover IC represents internal cup and CIC represents cover of the internal cup
Upper band
Lower band
Ram
an in
tens
ity (a
u)
1250 1300 1350 14001200 1450
CO2
150∘C 24 h
100∘C 24 h
90∘C 24 h
100∘C 24 h
Raman shift (cmminus1)
CaMg(CO3)2ndashSiO2ndashH2O
CaMg(CO3)2ndashSiO2ndashH2O
CaMg(CO3)2ndashSiO2ndashH2O
CaCO3ndashSiO2ndashH2O
(a)
Upper band
Lower band
Hot band
24 h
1200 1250 1300 1350 1400 1450
41 h
8 h
2 h
200∘C
Ram
an in
tens
ity (a
u)
Raman shift (cmminus1)
(b)
Figure 3 Raman spectra of the vapor phase in FSCCs containing (a) CaCO3ndashH2O and CaMg(CO
3)2ndashH2O after heating at 90ndash150∘C for 24 h
and (b) CaMg(CO3)2ndashH2O after heating at 200∘C from 2 to 41 h
of the CO2Fermi diad bands increased with experimental
duration up to about 120 h (200∘C) before eventually levelingoff (Figure 4 Table 1) Solid-phase characterization (seeSection 32) indicated that the dolomite was unlikely torun out over the length of the experiment Consequentlythe reaction reached an equilibrium state after reaction forsim120 hThe degree of the reaction (R) can be calculated using
the ratio between the total Raman peak area of CO2at time t
(A) and that at equilibrium state (119860lowast)
119877 () = 119860119860lowasttimes 100 (2)
As shown in Figure 4 (diamonds) the slope of R decreaseswith the increase of reaction time indicating that the
Geofluids 5
Table 1 Fermi diad bands splits and peak areas of CO2generated in the FSCC containing dolomite and water at 200∘C and the calculated
degree of reaction
Reaction time (h) Fermi diads and splits (cmminus1) Peak area Degree of reaction ()aV1
V2
Δ V1
V2
V1+ V2
0 mdash mdash mdash 0 0 0 02 128521 138792 10271 31587 36662 68249 1584 128519 138777 10258 53083 77521 130604 3026 128509 13877 10261 55164 81714 136878 3168 128514 138772 10258 59966 955 155466 35910 128484 138749 10265 73141 102321 175462 40620 128551 138804 10253 90065 141902 231967 53622 128545 1388 10255 100018 148336 248354 57428 128537 138795 10258 115519 171856 287375 66440 128543 138798 10255 13279 191084 323874 74843 128566 138821 10255 127099 188707 315806 73046 128576 138823 10247 138806 19958 338386 78249 128563 138817 10254 134642 192119 326761 75560 128539 138794 10255 13706 216374 353434 81765 128562 138816 10254 143307 220862 364169 84270 128559 138814 10255 145465 217231 362696 83887 128501 138757 10256 156179 230784 386963 89492 128549 138793 10244 162326 228882 391208 904104 128573 138811 10238 17136 245737 417097 964137 128567 138804 10237 172976 258905 431881149 128526 138799 10273 174657 250163 42482159 128538 138797 10259 183627 255395 439022171 128531 138793 10262 179781 259946 439727193 128524 138777 10253 169712 268104 437816203 128537 138795 10258 17552 255508 431028213 128566 138821 10255 174085 254889 428974224 12856 138815 10255 1725 25597 42847aThe total Raman peak area of CO2 at equilibrium state is an average of those after reaction for sim120 h Then the degree of reaction can be regarded as 100when the reaction time exceeds 120 h
reaction rates decrease with the increase of experimentaldurationPCO
2 The results also showed that the reaction
rate increased with increasing temperature For example theRaman intensity of CO2 was stronger at higher temperaturewithin a given period of time (Figure 3(a))
32 Solid-Phase Characterization Figure 5 shows XRD pat-terns of the quenched solid relicts in the fused silica tubesAfter heating at 200∘C for sim20 days the talc signals wereweak However heating for 80 days produced calcite andtalc as the main phases in the solid relicts whereas dolomitesignals were hardly visible in the XRD pattern (Figure 5)
The Raman spectrum of the solid phase before heat-ing (Figure 6) showed only dolomite peaks (sim177 30051098 cmminus1 [62]) indicating that the dolostone was of highpurity consistent with the XRD analysis However in addi-tion to dolomite characteristic calcite signals (sim282 and1086 cmminus1 [63]) and talc signals (1905 3605 and 675 cmminus1[64]) appeared after heating at 200∘C for 60 days
Figure 7 shows the morphology of the solid phaseafter heating at 200∘C for 60 days The solid phase has ahoneycomb-like texture and was widely distributed in therelicts (Figures 7(a)ndash7(d)) It was identified by EDS as talc(Figure 7(c)) The talc exhibited unoriented textures becauseit formed under strain-free conditions [21] Some cylindri-cal talc also occurred along the inner surface of the FSCC(Figure 7(d)) The dolomite grains had smooth edges (Fig-ure 7(c)) indicating dissolution during heating Some prod-ucts of rhombohedral calcite (Figure 7(d)) were also presentin the solid phase which formed along with the talc via reac-tion (1)
The amount of Mg-silicate mineral produced at 150∘Cfor 40 days was below the detection limit of the micro-XRD equipment Only dolomite and a small amount ofcalcite were observed in the XRD pattern after heating at150∘C for 40 days (Figure 5) This further supports the viewthat the metamorphic reaction rate is largely dependent ontemperature Some researchers view talc as the initial meta-morphic mineral for the CaMg(CO
3)2ndashSiO2ndashH2O system
6 Geofluids
TotalDegree of reaction
0
1000
2000
3000
4000
5000
Peak
area
0
20
40
60
80
100
Deg
ree o
f rea
ctio
n (
)
40 80 120 160 200 2400Reaction time (h)
sim1285minus1
simminus1
cmcm1385
Figure 4 Raman peak areas of CO2and the degree of reaction
versus reaction time at 200∘CBlack rectangles and red circles denotethe peak areas of the lower band at sim1285 cmminus1 and the upper bandat sim1385 cmminus1 respectively Blue triangles represent the total peakareas of both bandsThe green diamonds represent the degree of thereaction Data plotted are from Table 1
971
55 384
71
302
763
1645
283
81 258
822
4894
227
84
209
05 191
20
171
96
186
99
161
981
6004 1
5216
147
07 143
701
4219
133
691
3102
129
561
2440
123
451
1777
115
181
1437
402
133
6891
266
44
288
26
253
162
3986
219
03
201
262
0639
184
751
7863
156
49 154
19
138
75
110
89
104
471
0602
TalcCalciteDolomite
452
10
10 15 20 25 30 35 4052 (∘)Mo tube
20 days
40 days150∘C
200∘C
80 days200∘C
Figure 5 X-ray patterns of the solid relicts in FSCCs containingdolomite and water after heating at 150∘C for sim40 days (lower blueline) and at 200∘C for sim20 days (middle orange line) and sim80 days(upper black line)
(eg [4ndash6]) However serpentine minerals like lizardite andchrysotile are also likely to form at low temperatures duringmetamorphism of the CaOndashMgOndashSiO
2ndashH2OndashCO
2system
especially in contact or regional metamorphic settings [65ndash67] Some researchers have even pointed out that serpentineforms at lower temperatures than talc during metamorphism
CalciteDolomite
TalcRam
an in
tens
ity (a
u)
Solid phase
400 600 800 1000 1200200Raman shift (cmminus1)
(200∘C 60 days)
Figure 6 Raman spectrum of solid relicts after heating at 200∘C for60 daysThe reference spectra of dolomite calcite and talc were alsoshown for comparison The dolomite spectrum was acquired fromthe sample before heating The calcite spectrum was acquired fromcrystalline calcite and the reference spectrum of talc was cited froman open database hosted by the Department of Geosciences at theUniversity of Arizona (RRUFF Project httprruffinfoindexphp)
Table 2 Variations in the internal pressures of the HPOC contain-ing dolomite and water with experimental duration at 200∘C
serpentine is likely to form in a low-silica environment
Geofluids 7
(a) (b)
MgOSi
Dol
(c)
Talc
CaO
C
(d)
Figure 7 SEM micrographs and EDS analyses of the solid relicts in an FSCC containing dolomite and water after heating at 200∘C for sim60days (a b) Honeycomb-like talc (c) dolomite grains with smooth edges and EDS result of talc (yellow arrow) (d) euhedral calcite formed inthe relicts (white arrow) and cylindrical talc growing on the inner surface of the tube (yellow arrow)
further introduction of SiO2 will make talc stable relativeto serpentine [70ndash73] Considering the fact that talc wascharacterized as the product of Mg-silicate mineral in the200∘C experiment via reaction (1) we speculate that whilenot detected byXRD talc also formed below 200∘C sinceCO
2
was generated during the experiment (see above)
33 Thermodynamic Calculations Due to the limits of theUnithermdatabase we used aqueous silica as the SiO
2species
that participated in the reaction Considering that the solu-bility of amorphous silica was high at elevated temperatures[74] the calculated results should approximate the conditionsof the experiments The Gibbs free energy (Δ119866) of formationfor talc from CaMg(CO3)2 aqueous SiO2 and H
2O at the
pressure and temperature of interest are given in Table 3 TheΔ119866 of reaction decreases with increasing temperature at thesaturation pressure This indicates that the reaction is morefavorable at higher temperatures The Δ119866 becomes negativeat 119879 ge 80∘C which implies that the formation of product talcfrom dolomite and a silica-rich fluid is thermodynamicallyfavored However this reaction may not commence untileven higher temperatures are reached due to the probableinitial kinetic barrier to the reaction These thermodynamiccalculations support the implication from the experimentalresults that talc formation can occur at temperatures above100∘C
4 Discussion
41 Implications for the Formation of Mg-Carbonate-HostedTalc Geologically Prochaska [18] grouped the talc depositsinto five types (1) talc related to ultramafics (eg [13ndash15]) (2)Mg-carbonate-hosted talc (eg [20 37]) (3) metamorphictalc (eg [75 76]) (4) talc related to banded iron forma-tions (mostly minnesotaite [77 78]) and (5) secondary talcdeposits [18] The most economically viable of these depositsare usually related to the metamorphic reaction between anMg-carbonate infiltrated by a silica-rich hydrothermal fluid[18 20 21 37] Intense fractures that increase the permeabilityof geological fluid flow generally develop near such deposits[18 20 21 37 38]
Investigating the formation temperature of talc canimprove our understanding of its mineralization processThis has previously been done using several methods Theseinclude microthermometric measurements of relevant fluidinclusions (eg [39 40 79]) and calculations using talcndashdolo-mite oxygen isotope thermometry assuming that themineralpairs achieve oxygen isotope equilibrium [21 36] In additionthe phase diagram of the CaOndashMgOndashSiO2ndashCO2ndashH2O sys-tem has often been referred to for evaluating the formationtemperature of talc [5 35] The diagram was establishedbased on hydrothermal experiments geological case studiesand thermodynamic calculations [4 5 43 44] However the
8 Geofluids
Table 3 The Gibbs free energies of the reaction 3CaMg(CO3)2+ 4SiO
2(aq) + H
2O = Mg
3(Si4O10)(OH)
2+ 3CaCO
3+ 3CO
2at the
temperatures of interest and their corresponding saturation pressures
Temperature (∘C) Δ119866a (kJmol) 119875satb (bar) Temperature (∘C) ΔG (kJmol) 119875sat (bar)
25 7709 0032 100 ndash7083 101450 4663 0124 110 ndash9951 143460 2771 0199 120 ndash12938 198770 0609 0312 130 ndash16032 270380 ndash1778 0474 140 ndash19223 361590 ndash4351 0702 150 ndash22502 4761aΔ119866 refers to the Gibbs free energy of the reaction b119875sat represents the corresponding saturation pressures which are calculated based on the thermodynamicmodel proposed by Zhang and Duan [45]
experiments used to chart out this systemhave been generallyconducted at gt250∘C [4 41ndash44] The reaction path of thephase diagram at low temperatures was mainly establishedthrough thermodynamic calculations implying the need fortalc forming experiments at temperatures below 250∘C
Some geological case studies attribute low talc mineral-ization temperatures (lt200∘C) derived from adjacent talc anddolomite oxygen isotope thermometry to actually reflect iso-topic disequilibrium [36] This study shows that talc depositscan still form at temperatures below 200∘C on geologicaltime scales especially if the product CO
2can be released
(cf reaction (1)) However large-scale talc mineralization ismore likely to form at higher temperatures (eg 250ndash400∘C)Firstly PCO
2controls the lower thermal limit of talc stability
The onset temperature of the transformation increases withincreasing PCO
2 because CO
2is a product of the metamor-
phic reaction (1) and its presence greatly decreases the solu-bility of SiO
2in the fluid [80] CO
2is a common component
in geological fluids and can be either released from magmas(eg [81ndash84]) or generated from the hydrothermal alterationof carbonate (eg [85ndash87]) The oxidation (eg [88]) andhydrothermal maturation of organic matter are also naturalsources of CO
2[89 90]Therefore talcmineralization should
occur at relatively high temperatures in the presence of CO2
Secondly as our results have shown the reaction rate forreaction (1) increases sharply with increasing temperaturefacilitating talc deposits to form at higher temperatures
This study can also contribute to understanding the faultweakening mechanism in the upper crust The elastic strainaccumulation along a fault can be released through a suddenseismic slip (earthquake) or aseismic creep slip [32] A lowerfrictional coefficient for a fault will facilitate stable creepweakening the fault and suppressing the occurrence of strongearthquakes [35]The frictional coefficient of a fault generallydecreases with increasing temperature [35] Therefore faultsare likely to beweakened due to high temperatures in the deepcrust but not in the cool shallow crust The pervasive distri-bution of clay minerals along faults has also been thought toweaken faults [33ndash35 91ndash94] because layered clay mineralsexhibit much lower frictional coefficients than otherminerals[95] For example talc discovered along the SanAndreas faultzone is responsible for helping in aiding slippage along thefault [35 95] As shown here dolomite could react at le200∘Cwith silica-rich fluids traveling along fault planes to form
talc and hence might be an important mechanism of faultweakening in carbonate sequences in the upper crust
42 Implications for Hydrothermal Dolomite Reservoir Re-search Carbonate rock is the main type of hydrocarbonreservoir worldwide hosting over 60 of petroleum reserves[31] Dolomite hydrocarbon reservoirs are important com-prising about half of the carbonate hydrocarbon reser-voirs worldwide [96] Recent research has suggested thathydrothermal alteration can increase the porosity and per-meability of dolomite reservoirs substantially and is animportant factor affecting the development and distributionof dolomite reservoirs [24 25 97ndash101] The Tarim basin isone of the most important petroliferous basins in China andcontains a lower Palaeozoic carbonate series which is alsoan important hydrocarbon reservoir Recent exploration hasshown that silica-rich hydrothermal fluids have infiltratedthese carbonate series improving the physical properties ofthe reservoirs considerably (eg the Shunnan area of theTarim Basin [102 103]) It has been proposed that silica-richhydrothermal fluids were transported through extensionalfaults from the deep strata to the shallow carbonate sequencewhere they migrated laterally through porous and permeablecarbonate formations (sim6670m in the Shunnan area [104])Hydrothermal fluids originating in deep basins are generallyhot Microthermometric measurements have indicated thatthe silica-rich hydrothermal fluids in the Tarim basin reachover 200∘C [101 103] Given that the lower part of the lowerPalaeozoic sequence is mainly composed of dolomite silica-rich hydrothermal fluids could react with the dolomite toform talc and thus change the physical properties of the reser-voir Recently petrologic and diagenetic research haverevealed pervasive silicification in Early Cretaceous ultra-deep water carbonate reservoirs in the Atlantic Ocean off-shore from Brazil [105] The presence of talc calcite quartzand dolomite on the thin-section scale may indicate that thedolomite was strongly corroded by a silica-rich hydrothermalfluid
Alteration of dolomite to talcwill alsomodify the porosityand permeability of carbonate hydrocarbon reservoirs [29ndash31] The silica required for the mineral alteration can be pro-vided by either silica-rich hydrothermal fluids or silica (egquartz chert and opal) within the carbonate reservoirs [106]If SiO
2derives from quartzchert in the dolomite sequences
Geofluids 9
the hydrothermal alteration would increase the porosity ofthe dolomite reservoirs McKinley et al [29] reported thatthe total volume of minerals within a dolomite reservoir canbe reduced by 13 to 17 through the reaction betweendolomite and quartz in reaction (1) In addition the reactionbetween dolomite and silica-rich hydrothermal fluids can actas an important source of CO
2 in hydrocarbon reservoirsThepresence of CO2 can lower the pH of the formation waterand thus promote the dissolution of carbonate minerals [60107 108] increasing the porosity of the reservoirs [109ndash111]However the pore throats may be blocked by the formationof talc or other clay minerals [29 112] Therefore moredetailed factors should be considered in order to unequi-vocally evaluate the effects of silica-rich hydrothermal fluidsin dolomite reservoirs
Although talc can form from the interaction betweendolomite and silica-rich fluids at low temperatures it isseldom observed in hydrocarbon reservoirs [29 31] for thefollowing two reasons (1)A large amount of CO
2can be pro-
duced by the maturation of organic matter and the reactionbetween carbonate minerals and organic acid [98 101] Thepresence of CO
2decreases the lower thermal stability field
of talc [113] (2)The reaction path is dependent on the com-position of the hydrothermal fluid For example K+ andAl3+ are also important components of geological fluidsMontmorillonite instead of talc is more likely to form inthe presence of only a small quantity of Al3+ [41] and theformation of talc can also be inhibited by K+ [29]
43 Implications for High PndashT Experiment Using Fused SilicaCapillary Tubes as Reactors FSCCs are used to constructsynthetic fluid inclusions containing organic and inorganiccomponents [46] They offer advantages such as being inertto many components especially acids and S allowing forthe convenient synthesis of fluid inclusions and facilitatingin situ optical and Raman spectroscopic observations (eg[57 114ndash117]) Fused silica tubes can tolerate relatively hightemperatures up to 600∘C and pressures up to 300MPa As aresult FSCCs are used in many research fields For examplein addition to construction of synthetic fluid inclusions[46 53 118] FSCCs were used in studying the propertiesof hydrothermal fluids as optical and Raman spectroscopiccells [115ndash117 119ndash121] FSCCs were also used as reactorsin investigating the mechanism of thermochemical sulfatereduction [114] and the decomposition of organic matter[57]
However SiO2 in the FSCC acted as a reagent in thisstudy and was partially dissolved as indicated by the pitson the inner surface of the tube (Figures 8(a)ndash8(d)) Thedissolution of silica from FSCCs containing alkali sulfatesolutions was also observed after quenching from ge350∘C(Figures 8(e) and 8(f)) The severe dissolution of fused silicacan be ascribed to three factors (1) Amorphous silica ismore soluble than quartz especially at high temperaturesIn neutral solutions its solubility increases sharply withtemperature from 100 ppm at 20∘C to 1500 ppm at 310∘C[74 122 123] (2) Under basic conditions the solubility ofamorphous silica is greatly enhanced by the ionization ofsilicic acid (H
4SiO4+ OHminus rarr H
3SiO4
minus + H2O [124]) (3)
SiO2may act as a reagent as it did in this experiment The
presence of dissolution pits will weaken the mechanicalstrength of the silica tube In addition the presence ofdissolved silica can make the system more complicated thanexpected Therefore the solubility and reactivity of silicaunder hydrothermal conditions should be evaluated beforeFSCCs are used as reactors
5 Conclusion
The reactions in the CaMg(CO3)2ndashSiO2ndashH2O system atlow temperatures were investigated using fused silica tubesas reactors Results showed that dolomite reacted with asilica-rich fluid to form talc calcite and CO2 at le200
∘Cand low PCO2 The reaction rate increased with increasingtemperature and decreased with rising PCO2Therefore hightemperature and the presence of a conduit to release CO2 willpromote the formation of talcThis experiment has importantgeological and geochemical implications(1)Theresults confirmed themechanism of talcminerali-
zation in Mg-carbonate hosted talc deposits Dolomitereacted with silica-rich hydrothermal fluids to form talccalcite and CO
2 Talc could form at le200∘C whereas pre-
vious hydrothermal experiments examining the CaOndashMgOndashSiO2ndashCO2ndashH2O system were mainly conducted at gt250∘C
However considering the effect of temperature on thereaction rate and other geological conditions massive talcdeposits are still more likely to form at higher temperaturesThe formation of talc along a fault in a Mg-carbonateformation will also weaken the fault thus preventing strongearthquakes(2) Talc in carbonate reservoirs can indicate the activity
of silica-rich hydrothermal fluids Fluid-aided alteration ofdolomite can change the physical properties of dolomitereservoirs substantially The reaction between dolomite andquartz within the carbonate can decrease the total volume ofminerals by 13ndash17 The generation of CO2 can promotethe dissolution of carbonate minerals elsewhere under theappropriate conditions increasing the porosity and perme-ability of carbonate reservoirs However talc minerals mayblock pore throats in the reservoirs Therefore additionalfactors need to be considered when evaluating the effectsof CaMg(CO
3)2ndashSiO2ndashH2O interactions on the physical
properties of carbonate reservoirs(3) The solubility and reactivity of silica should be con-
sidered when using fused silica tubes as reactors in highPndashT experiments The dissolution of silica will increase thecomplexity of the system andweaken themechanical strengthof the tube
Conflicts of Interest
The authors declare that they have no conflicts of interest
Acknowledgments
The dolomite sample was provided by Mr Chunhua ShiMisses Yang Qu Wanlu Gao and Ye Qiu helped the authorsa lot during the micro-XRD analysis and HPOC experiment
10 Geofluids
Outer surfaceInner surface
(a) (b)In
ner s
urfa
ce
(c) (d)
Inner surface
(e) (f)
Figure 8 SEM images of the inner surface of the silica tube (a) Smooth inner surface before the reaction (b) magnification of the squarearea shown in (a) (c) dissolution pits on the inner surface after heating at 200∘C for sim60 days (d) magnification of (c) severe erosion of thesilica on the inner surface of FSCCs containing (e) 10m Na
2SO4and (f) 10m Li
2SO4after heating at 350∘C for 1 h
Dr Rui Wang and Miss Siyu Hu are also thanked for theirhelp in the thermodynamic calculations of the reactionsThis work was financially supported by the National NaturalScience Foundation of China (Grant nos 41230312 and41573054) I-Ming Chou is thankful for the support of theKnowledge Innovation Program (SIDSSE-201302) and theHadal-trench Research Program (XDB06060100) of ChineseAcademy of Sciences
References
[1] L D Meinert ldquoSkarns and skarn depositsrdquo Geoscience Canadavol 19 no 4 pp 145ndash162 1992
[2] L D Meinert G M Dipple and S Nicolescu ldquoWorld skarndepositsrdquo Economic Geology 100th Anniversary Volume pp299ndash336 2005
[3] Y Yao J Chen J Lu R Wang and R Zhang ldquoGeology andgenesis of the Hehuaping magnesian skarn-type cassiterite-sulfide deposit Hunan Province Southern ChinardquoOre GeologyReviews vol 58 no C pp 163ndash184 2014
[4] T M Gordon and H J Greenwood ldquoThe reaction dolomite+ quartz + water = talc + calcite + carbon dioxiderdquo AmericanJournal of Science vol 268 pp 225ndash242 1970
[5] M B Holness ldquoFluid flow paths and mechanisms of fluidinfiltration in carbonates during contact metamorphism TheBeinn an Dubhaich aureole Skyerdquo Journal of MetamorphicGeology vol 15 no 1 pp 59ndash70 1997
Geofluids 11
[6] W Heinrich S S Churakov andM Gottschalk ldquoMineral-fluidequilibria in the system CaOndashMgOndashSiO
2ndashH2OndashCO
2ndashNaCl
and the record of reactive fluid flow in contact metamorphicaureolesrdquo Contributions to Mineralogy and Petrology vol 148no 2 pp 131ndash149 2004
[7] M Wesołowski ldquoThermal decomposition of talc a reviewrdquoThermochimica Acta vol 78 no 1-3 pp 395ndash421 1984
[8] L A Perez-Maqueda A Duran and J L Perez-RodrıguezldquoPreparation of submicron talc particles by sonicationrdquoAppliedClay Science vol 28 no 1-4 pp 245ndash255 2005
[9] R L Johnson ldquoTalcrdquoAmerican Ceramic Society Bulletin vol 71pp 818ndash820 1992
[10] R L Johnson and R L Virta ldquoTalcrdquo American Ceramic SocietyBulletin vol 79 pp 79ndash81 2000
[11] M Z Abzalov ldquoChrome-spinels in gabbro-wehrlite intrusionsof the Pechenga area Kola Peninsula Russia emphasis onalteration featuresrdquo Lithos vol 43 no 3 pp 109ndash134 1998
[12] M F El-Sharkawy ldquoTalc mineralization of ultramafic affinity inthe Eastern Desert of Egyptrdquo Mineralium Deposita vol 35 no4 pp 346ndash363 2000
[13] M Franceschelli G Carcangiu A M Caredda G CrucianiI Memmi and M Zucca ldquoTransformation of cumulate maficrocks to granulite and re-equilibration in amphibolite andgreenschist facies in NE Sardinia Italyrdquo Lithos vol 63 no 1-2pp 1ndash18 2002
[14] S G Tesalina P Nimis T Auge and V V Zaykov ldquoOriginof chromite in mafic-ultramafic-hosted hydrothermal massivesulfides from the Main Uralian Fault South Urals RussiardquoLithos vol 70 no 1-2 pp 39ndash59 2003
[15] D M Evans ldquoMetamorphic modifications of the Muremeramafic-ultramafic intrusions eastern Burundi and their effecton chromite compositionsrdquo Journal of African Earth Sciencesvol 101 pp 19ndash34 2015
[16] T Yamanaka K Maeto H Akashi et al ldquoShallow submarinehydrothermal activity with significant contribution of mag-matic water producing talc chimneys in the Wakamiko CraterofKagoshimaBay southernKyushu Japanrdquo Journal of Volcanol-ogy and Geothermal Research vol 258 pp 74ndash84 2013
[17] B Moine J P Fortune P Moreau and F Viguier ldquoComparativemineralogy geochemistry and conditions of formation of twometasomatic talc and chlorite deposits Trimouns PyreneesFrance and Rabenwald eastern Alps Austriardquo Economic Geol-ogy vol 84 no 5 pp 1398ndash1416 1989
[18] W Prochaska ldquoGeochemistry and genesis of Austrian talcdepositsrdquo Applied Geochemistry vol 4 no 5 pp 511ndash525 1989
[19] P de Parseval S Jiang F Fontan R Wang F Martin and JFreeet ldquoGeology and ore genesis of the Trimouns talc-chloriteore deposit Pyrenees Francerdquo Acta Petrologica Sinica vol 20no 4 pp 877ndash886 2004
[20] A C Gondim and S Jiang ldquoGeologic characteristics and gene-ticmodels for the talc deposits in Parana andBahia BrazilrdquoActaPetrologica Sinica vol 20 no 4 pp 829ndash836 2004
[21] P Boulvais P de Parseval A DrsquoHulst and P Paris ldquoCarbonatealteration associated with talc-chlorite mineralization in theeastern Pyrenees with emphasis on the St Barthelemy MassifrdquoMineralogy and Petrology vol 88 no 3-4 pp 499ndash526 2006
[22] G R Davies and L B Smith Jr ldquoStructurally controlled hydro-thermal dolomite reservoir facies an overviewrdquoAAPG Bulletinvol 90 no 11 pp 1641ndash1690 2006
[23] J Lonnee and H G Machel ldquoPervasive dolomitization withsubsequent hydrothermal alteration in theClarke Lake gas field
Middle Devonian Slave Point Formation British ColumbiaCanadardquo AAPG Bulletin vol 90 no 11 pp 1739ndash1761 2006
[24] J A Luczaj ldquoEvidence against the Dorag (mixing-zone) modelfor dolomitization along theWisconsin arch - A case for hydro-thermal diagenesisrdquo AAPG Bulletin vol 90 no 11 pp 1719ndash1738 2006
[25] L B Smith Jr ldquoOrigin and reservoir characteristics of UpperOrdovician Trenton-Black River hydrothermal dolomite reser-voirs in New YorkrdquoAAPG Bulletin vol 90 no 11 pp 1691ndash17182006
[26] J Parnell ldquoDevonianMagadi-type cherts in theOrcadian BasinScotlandrdquo Journal of Sedimentary Petrology vol 56 no 4 pp495ndash500 1986
[27] J M Garcıa-Ruiz ldquoCarbonate precipitation into alkaline silica-rich environmentsrdquo Geology vol 26 no 9 pp 843ndash846 1998
[28] J Zhang W Hu Y Qian et al ldquoFormation of saddle dolomitesin Upper Cambrian carbonates western Tarim Basin (north-west China) implications for fault-related fluid flowrdquo Marineand Petroleum Geology vol 26 no 8 pp 1428ndash1440 2009
[29] J M McKinley R H Worden and A H Ruffell ldquoContactdiagenesis the effect of an intrusion on reservoir quality in thetriassic sherwood sandstone group Northern Irelandrdquo Journalof Sedimentary Research vol 71 no 3 pp 484ndash495 2001
[30] S Dong D Chen H Qing et al ldquoHydrothermal alteration ofdolostones in the Lower Ordovician Tarim Basin NW Chinamultiple constraints from petrology isotope geochemistry andfluid inclusion microthermometryrdquo Marine and PetroleumGeology vol 46 pp 270ndash286 2013
[31] V Madrucci C W D D Anjos R A Spadini D B Alvesand S M C Anjos ldquoAuthigenic magnesian clays in carbonatereservoirs in Brazilrdquo in Proceedings of the 15th International ClayConference Rio De Janeiro Brazil 2013
[32] C H Scholz ldquoEarthquakes and friction lawsrdquo Nature vol 391no 6662 pp 37ndash42 1998
[33] A M Schleicher B A Van Der Pluijm J G Solum andL N Warr ldquoOrigin and significance of clay-coated fracturesin mudrock fragments of the SAFOD borehole (ParkfieldCalifornia)rdquoGeophysical Research Letters vol 33 no 16 ArticleID L16313 2006
[34] A M Schleicher B A van der Pluijm and L N Warr ldquoNano-coatings of clay and creep of the San Andreas fault at ParkfieldCaliforniardquo Geology vol 38 no 7 pp 667ndash670 2010
[35] C Collettini C Viti S A F Smith and R E HoldsworthldquoDevelopment of interconnected talc networks and weakeningof continental low-angle normal faultsrdquo Geology vol 37 no 6pp 567ndash570 2009
[36] F Tornos and B F Spiro ldquoThe geology and isotope geochem-istry of the talc deposits of Puebla de Lillo (Cantabrian zonenorthern Spain)rdquo Economic Geology vol 95 no 6 pp 1277ndash1296 2000
[37] L Hecht R Freiberger H A Gilg G Grundmann and Y AKostitsyn ldquoRare earth element and isotope (C O Sr) charac-teristics of hydrothermal carbonates genetic implications fordolomite-hosted talc mineralization at Gopfersgrun (Fichtelge-birge Germany)rdquo Chemical Geology vol 155 no 1-2 pp 115ndash130 1999
[38] R Sharma P Joshi and P D Pant ldquoThe role of fluids inthe formation of talc deposits of Rema area Kumaun LesserHimalayardquo Journal of the Geological Society of India vol 73 no2 pp 237ndash248 2009
12 Geofluids
[39] P De Parseval B Moine J P Fortune and J Ferret ldquoFluid-mineral interactions at the origin of the Trimouns talc andchlorite deposit (Pyrenees France)rdquo in Current Research inGeology Applied to Ore Deposits P Fenoll Hach-Ali J Torrez-Ruiz and F Gervilla Eds pp 205ndash209 University of GranadaGranada Granada Spain 1993
[40] M C Boiron P Boulvais M Cathelineau D Banks N Cal-vayrac and G Hubert ldquoFluid circulation at the origin of thetrimouns talc deposit (Pyrenees France)rdquo in Proceedings of the18th Meeting of European Current Research on Fluid InclusionsSiena Italy 2005
[41] P Bayliss andA A Levhinson ldquoLow temperature hydrothermalsynthesis from dolomite or calcite quartz and kaoliniterdquo Claysand Clay Minerals vol 19 no 2 pp 109ndash114 1971
[42] G Skippen ldquoAn experimental model for low pressure meta-morphism of siliceous dolomitic marblerdquo American Journal ofScience vol 274 no 5 pp 487ndash509 1974
[43] J Slaughter D M Kerrick and V J Wall ldquoExperimen-tal and thermodynamic study of equilibria in the systemCaOndashMgOndashSiO
2ndashH2OndashCO
2rdquoAmerican Journal of Science vol
275 pp 143ndash162 1975[44] R G Eggert and D M Kerrick ldquoMetamorphic equilibria in the
siliceous dolomite system 6 kbar experimental data and geo-logic implicationsrdquo Geochimica et Cosmochimica Acta vol 45no 7 pp 1039ndash1049 1981
[45] Z Zhang and Z Duan ldquoPrediction of the PVT properties ofwater over wide range of temperatures and pressures frommolecular dynamics simulationrdquo Physics of the Earth andPlanetary Interiors vol 149 no 3-4 pp 335ndash354 2005
[46] I-M Chou Y Song and R C Burruss ldquoA newmethod for syn-thesizing fluid inclusions in fused silica capillaries containingorganic and inorganic materialrdquo Geochimica et CosmochimicaActa vol 72 no 21 pp 5217ndash5231 2008
[47] I-M Chou R C Burruss and W J Lu ldquoA new optical cellfor spectroscopic studies of geologic fluids at pressures up to100MPardquo in Advances in High-Pressure Technology for Geo-physical Applications J Chen YWang T S Duffy G Shen andL F Dobrzhinetakaya Eds pp 475ndash485 Elsevier AmsterdamNetherlands 2005
[48] K M Rosso and R J Bodnar ldquoMicrothermometric and Ramanspectroscopic detection limits of CO
2in fluid inclusions and the
Raman spectroscopic characterization of CO2rdquo Geochimica et
Cosmochimica Acta vol 59 no 19 pp 3961ndash3975 1995[49] H M Lamadrid Geochemistry of fluid-rock processes [Doctoral
dissertation] Virginia Polytechnic Institute and State Univer-sity Blacksburg VA USA 2016
[50] J H Parker D W Feldman and M Ashkin ldquoRaman scatteringby silicon and germaniumrdquo Physical Review vol 155 no 3 pp712ndash714 1967
[51] Y V Shvarov ldquoAlgorithmization of the numeric equilibriummodeling of dynamic geochemical processesrdquo GeochemistryInternational vol 37 no 6 pp 571ndash576 1999
[52] R B Wright and C H Wang ldquoDensity effect on the Fermiresonance in gaseous CO
2by Raman scatteringrdquoThe Journal of
Chemical Physics vol 58 no 7 pp 2893ndash2895 1973[53] XWang I-M ChouWHu R C Burruss Q Sun and Y Song
ldquoRaman spectroscopic measurements of CO2density experi-
mental calibration with high-pressure optical cell (HPOC) andfused silica capillary capsule (FSCC) with application to fluidinclusion observationsrdquo Geochimica et Cosmochimica Acta vol75 no 14 pp 4080ndash4093 2011
[54] H R Gordon and T K McCubbin Jr ldquoThe 28-micron bandsof CO
2rdquo Journal of Molecular Spectroscopy vol 19 no 1ndash4 pp
137ndash154 1966[55] T Azbej M J Severs B G Rusk and R J Bodnar ldquoIn situ
quantitative analysis of individual H2O-CO
2fluid inclusions by
laser Raman spectroscopyrdquo Chemical Geology vol 237 no 3-4pp 255ndash263 2007
[56] Y Song I M Chou W Hu B Robert and W Lu ldquoCO2
density-raman shift relation derived from synthetic inclusionsin fused silica capillaries and its applicationrdquo Acta GeologicaSinica (English Edition) vol 83 pp 932ndash938 2009
[57] Z Pan I-M Chou and R C Burruss ldquoHydrolysis of polycar-bonate in sub-critical water in fused silica capillary reactor within situ Raman spectroscopyrdquo Green Chemistry vol 11 no 8 pp1105ndash1107 2009
[58] M L Frezzotti F Tecce and A Casagli ldquoRaman spectroscopyfor fluid inclusion analysisrdquo Journal of Geochemical Explorationvol 112 pp 1ndash20 2012
[59] E L Shock and H C Helgeson ldquoCalculation of the thermo-dynamic and transport properties of aqueous species at highpressures and temperatures correlation algorithms for ionicspecies and equation of state predictions to 5 kb and 1000∘CrdquoGeochimica et Cosmochimica Acta vol 52 no 8 pp 2009ndash20361988
[60] O S Pokrovsky SVGolubev J Schott andACastillo ldquoCalcitedolomite and magnesite dissolution kinetics in aqueous solu-tions at acid to circumneutral pH 25 to 150∘C and 1 to 55 atmpCO2 New constraints on CO
2sequestration in sedimentary
basinsrdquo Chemical Geology vol 265 no 1-2 pp 20ndash32 2009[61] YGarrabos R Tufeu B LeNeindre G Zalczer andD Beysens
ldquoRayleigh andRaman scattering near the critical point of carbondioxiderdquo The Journal of Chemical Physics vol 72 no 8 pp4637ndash4651 1979
[62] J H Nicola J F Scott R M Couto andMM Correa ldquoRamanspectra of dolomite [CaMg(CO
3)2]rdquo Physical Review B vol 14
no 10 pp 4676ndash4678 1976[63] S Gunasekaran G Anbalagan and S Pandi ldquoRaman and
infrared spectra of carbonates of calcite structurerdquo Journal ofRaman Spectroscopy vol 37 no 9 pp 892ndash899 2006
[64] G J Rosasco and J J Blaha ldquoRaman microprobe spectra andvibrationalmode assignments of talcrdquoApplied Spectroscopy vol34 no 2 pp 140ndash144 1980
[65] V Trommsdorff and B W Evans ldquoAntigorite-ophicarbo-nates phase relations in a portion of the system CaOndashMgOndashSiO2ndashH2OndashCO
2rdquo Contributions to Mineralogy and Petrology
vol 60 no 1 pp 39ndash56 1977[66] V Trommsdorff and J A D Connolly ldquoConstraints on phase
diagram topology for the systemCaOndashMgOndashSiO2ndashCO2ndashH2Ordquo
Contributions to Mineralogy and Petrology vol 104 no 1 pp 1ndash7 1990
[67] B S Van Gosen H A Lowers S J Sutley and C A GentldquoUsing the geologic setting of talc deposits as an indicator ofamphibole asbestos contentrdquo Environmental Geology vol 45no 7 pp 920ndash939 2004
[68] W Johannes ldquoAn experimental investigation of the systemMgO-SiO
2-H2O-CO
2rdquo American Journal of Science vol 267
no 9 pp 1083ndash1104 1969[69] E S Schandl and M P Gorton ldquoHydrothermal alteration and
CO2metasomatism (natural carbon sequestration) of komati-
ites in the south-western Abitibi greenstone beltrdquo CanadianMineralogist vol 50 no 1 pp 129ndash146 2012
Geofluids 13
[70] B W Evans and S Guggenheim ldquoTalc phyrophyllite andrelated mineralsrdquo in Reviews in Mineralogy S W Bailey Edvol 19 pp 225ndash294 1988
[71] B Velde ldquoExperimental pseudomorphism of diopside by talcand serpentine in (Ni Mg)Cl
2aqueous solutionsrdquo Geochimica
et Cosmochimica Acta vol 52 no 2 pp 415ndash424 1988[72] A E Williams-Jones C Normand H Clark Vali Jr R F
Martin A Dufresne and Nayebzadeh A ldquoControls of amphi-bole formation in chrysotile from the Jeffrey Mine AsbestosQuebecrdquo inTheHealth Effects Effects of Chrysotile Asbestos R PNolan AM LangerM RossWicks F J andMartin F R Edsvol 5 pp 89ndash104 The Mineralogical Association of CanadaQuebec Quebec Canada 2001
[73] B W Evans ldquoThe serpentinite multisystem revisited chrysotileis metastablerdquo International Geology Review vol 46 no 6 pp479ndash506 2004
[74] I Gunnarsson and S Arnorsson ldquoAmorphous silica solubilityand the thermodynamic properties of H
4SiO∘4in the range of
0∘ to 350∘C at Psatrdquo Geochimica et Cosmochimica Acta vol 64no 13 pp 2295ndash2307 2000
[75] M W Bodine Jr ldquoTrioctahedral clay mineral assemblages inPaleozoic marine evaporite rocksrdquo in Proceedings of the Pre-sented in the Sixth International Symposium on Salt vol 1 pp267ndash284 Toronto Canada 1983
[76] W Schreyer and K Abraham ldquoThree-stage metamorphic his-tory of a whiteschist from Sar e Sang Afghanistan as part ofa former evaporite depositrdquo Contributions to Mineralogy andPetrology vol 59 no 2 pp 111ndash130 1976
[77] T Angerer and S G Hagemann ldquoThe BIF-hosted high-gradeiron ore deposits in the archean koolyanobbing greenstonebelt Western Australia structural control on synorogenic-and weathering-related magnetite- hematite- and goethite-rich iron orerdquo Economic Geology vol 105 no 5 pp 917ndash9452010
[78] P Duuring and S Hagemann ldquoLeaching of silica bands andconcentration of magnetite in Archean BIF by hypogene fluidsBeebyn Fe ore deposit Yilgarn Craton Western AustraliardquoMineralium Deposita vol 48 no 3 pp 341ndash370 2013
[79] D Shin and I Lee ldquoFluid inclusions and their stable isotopegeochemistry of the carbonate-hosted talc deposits near theCretaceous Muamsa Granite South Koreardquo Geochemical Jour-nal vol 40 no 1 pp 69ndash85 2006
[80] P G Novgorodov ldquoSolubility of quartz in anH2OndashCO
2mixture
at 700 degrees C and pressures of 3 and 5 kbarsrdquoGeokhimiya pp1484ndash1489 1975
[81] T M Gerlach ldquoChemical characteristics of the volcanic gasesfrom Nyiragongo lava lake and the generation of CH
4-rich
fluid inclusions in alkaline rocksrdquo Journal of Volcanology ampGeothermal Research vol 8 no 2-4 pp 177ndash189 1980
[82] J V Walther and P M Orville ldquoVolatile production and trans-port in regional metamorphismrdquo Contributions to Mineralogyand Petrology vol 79 no 3 pp 252ndash257 1982
[83] W F Giggenbach ldquoThe origin and evolution of fluids inmagmatic-hydrothermal systemsrdquo in Geochemistry of Hydro-thermalOreDeposits H L Barnes Ed pp 737ndash796WileyNewYork NY USA 3 edition 1997
[84] J B Lowenstern ldquoCarbon dioxide in magmas and implicationsfor hydrothermal systemsrdquoMineralium Deposita vol 36 no 6pp 490ndash502 2001
[85] R Kerrich and W S Fyfe ldquoThe gold-carbonate associationsource of CO
2 and CO
2fixation reactions in Archaean lode
depositsrdquo Chemical Geology vol 33 no 1ndash4 pp 265ndash294 1981
[86] P I Nabelek ldquoCalc-silicate reactions and bedding-controlledisotopic exchange in the Notch Peak aureole Utah implicationsfor differential fluid fluxes with metamorphic graderdquo Journal ofMetamorphic Geology vol 20 no 4 pp 429ndash440 2002
[87] P I Nabelek ldquoFluid evolution and kinetics of metamorphicreactions in calc-silicate contact aureoles - From H
2O to CO
2
and backrdquo Geology vol 35 no 10 pp 927ndash930 2007[88] H G Machel ldquoBacterial and thermochemical sulfate reduction
in diagenetic settings - old and new insightsrdquo SedimentaryGeology vol 140 no 1-2 pp 143ndash175 2001
[89] L Stalker P Farrimond and S R Larter ldquoWater as an oxygensource for the production of oxygenated compounds (includingCO2precursors) during kerogen maturationrdquo Organic Geo-
chemistry vol 22 no 3-5 pp 477ndashIN4 1994[90] Z K Shipton J P Evans D Kirschner P T Kolesar A P
Williams and J Heath ldquoAnalysis of CO2leakage through lsquolow-
permeabilityrsquo faults from natural reservoirs in the ColoradoPlateau east-central Utahrdquo Geological Society Special Publica-tion vol 233 pp 43ndash58 2004
[91] J Byerlee ldquoFriction overpressure and fault normal compres-sionrdquo Geophysical Research Letters vol 17 no 12 pp 2109ndash21121990
[92] C Morrow B Radney and J Byerlee ldquoChapter 3 frictionalstrength and the effective pressure law of montmorillonite andlllite claysrdquo International Geophysics vol 51 no C pp 69ndash881992
[93] C A Morrow D E Moore and D A Lockner ldquoThe effectof mineral bond strength and adsorbed water on fault gougefrictional strengthrdquo Geophysical Research Letters vol 27 no 6pp 815ndash818 2000
[94] D A Lockner C Morrow D Moore and S Hickman ldquoLowstrength of deep San Andreas fault gouge from SAFOD corerdquoNature vol 472 no 7341 pp 82ndash86 2011
[95] D EMoore andM J Rymer ldquoTalc-bearing serpentinite and thecreeping section of the San Andreas faultrdquo Nature vol 448 no7155 pp 795ndash797 2007
[96] DH Zenger ldquoDiscussion lsquoOn the formation and occurrence ofsaddle dolomitersquordquo Journal of Sedimentary Petrology vol 51 no4 pp 1350ndash1352 1981
[97] DAKatzG P Eberli P K Swart andL B Smith Jr ldquoTectonic-hydrothermal brecciation associated with calcite precipitationand permeability destruction in Mississippian carbonate reser-voirs Montana and Wyomingrdquo AAPG Bulletin vol 90 no 11pp 1803ndash1841 2006
[98] M Esteban and C Taberner ldquoSecondary porosity developmentduring late burial in carbonate reservoirs as a result of mixingandor cooling of brinesrdquo Journal of Geochemical Explorationvol 78-79 pp 355ndash359 2003
[99] H G MacHel ldquoInvestigations of burial diagenesis in carbonatehydrocarbon reservoir rocksrdquoGeoscience Canada vol 32 no 3pp 103ndash128 2005
[100] J A Sagan and B S Hart ldquoThree-dimensional seismic-baseddefinition of fault-related porosity development Trenton-BlackRiver interval Saybrook Ohiordquo AAPG Bulletin vol 90 no 11pp 1763ndash1785 2006
[101] F Xing and S Li ldquoGenesis and environment characteristics ofdolomite-hosted quartz and its significance for hydrocarbonexploration in Keping Area Tarim Basin Chinardquo Journal ofEarth Science vol 23 no 4 pp 476ndash489 2012
[102] L Yun and Z Cao ldquoHydrocarbon enrichment pattern andexploration potential of the Ordovician in Shunnan area TarimBasinrdquo Oil and Gas Geology vol 35 no 6 pp 788ndash797 2014
14 Geofluids
[103] Y Li N Ye X Yuan Q Huang B Su and R Zhou ldquoGeologicaland geochemical characteristics of silicified hydrothermal fluidsin Well Shunnan 4 Tarim Basinrdquo Oil and Gas Geology vol 36no 6 pp 934ndash944 2015
[104] L Qi ldquoOil and gas breakthrough in ultra-deep Ordoviciancarbonate formations in Shuntuoguole uplift Tarim BasinrdquoChina Petroleum Exploration vol 21 no 3 pp 38ndash51 2016 (inChinese with English abstract)
[105] H R Qing ldquoAn introduction of petrology and diagenesis ofultra-deep water carbonate reservoirs from the Atlantic Oceanoffshore Brazilrdquo 2017 Oral presentation at Wuxi Institute ofPetroleum Geology of SINOPEC Wuxi China
[106] G J Simandl and S Paradisl ldquoCarbonate-hosted talcrdquo SelectedBritish ColumbiaMineral Deposit Profiles vol 3 pp 35ndash38 1999
[107] Y K Kharaka D R Cole S D Hovorka W D Gunter K GKnauss and BM Freifeld ldquoGas-water-rock interactions in FrioFormation following CO
2injection implications for the storage
of greenhouse gases in sedimentary basinsrdquoGeology vol 34 no7 pp 577ndash580 2006
[108] Z Duan and D Li ldquoCoupled phase and aqueous speciesequilibrium of the H
2OndashCO
2ndashNaClndashCaCO
3system from 0 to
250∘C 1 to 1000 bar with NaCl concentrations up to saturationof haliterdquo Geochimica et Cosmochimica Acta vol 72 no 20 pp5128ndash5145 2008
[109] M R Giles and J DMarshall ldquoConstraints on the developmentof secondary porosity in the subsurface re-evaluation of pro-cessesrdquoMarine and PetroleumGeology vol 3 no 3 pp 243ndash2551986
[110] O S Pokrovsky S V Golubev and J Schott ldquoDissolution kinet-ics of calcite dolomite and magnesite at 25∘C and 0 to 50 atmpCO2rdquo Chemical Geology vol 217 no 3-4 pp 239ndash255 2005
[111] P Cao Z T Karpyn and L Li ldquoThe role of host rock pro-perties in determining potential CO
2migration pathwaysrdquo
International Journal of Greenhouse Gas Control vol 45 pp 18ndash26 2016
[112] M D Fishburn ldquoSignificant results of deep drilling at ElkHills Kern County Californiardquo in Structure Stratigraphy andHydrocarbon Occurrences of the San Joaquin Basin CaliforniaG K Kuespert and S A Reid Eds vol 64 pp 157ndash167 PacificSections Society of Economic Paleontologists and Mineralo-gists and American Association of Petroleum Geologists 1990
[113] E Povoden M Horacek and R Abart ldquoContact metamor-phism of siliceous dolomite and impure limestones from theWerfen formation in the eastern Monzoni contact aureolerdquoMineralogy and Petrology vol 76 no 1-2 pp 99ndash120 2002
[114] S Yuan I-M Chou R C Burruss X Wang and J Li ldquoDispro-portionation and thermochemical sulfate reduction reactions inSndashH2OndashCH
4and SndashD
2OndashCH
4systems from 200 to 340∘C at
elevated pressuresrdquo Geochimica et Cosmochimica Acta vol 118pp 263ndash275 2013
[115] X Wang I-M Chou W Hu and R C Burruss ldquoIn situ obser-vations of liquid-liquid phase separation in aqueous MgSO
4
solutions geological and geochemical implicationsrdquo Geochim-ica et Cosmochimica Acta vol 103 pp 1ndash10 2013
[116] X Wang Y Wan W Hu et al ldquoIn situ observations of liquid-liquid phase separation in aqueous ZnSO
4solutions at tem-
peratures up to 400∘C Implications for Zn2+ndashSO2minus4
[117] X Wang IM Chou W Hu Y Wan and Z Li ldquoPropertiesof lithium under hydrothermal conditions revealed by in situ
Raman spectroscopic characterization of Li2O-SO
3-H2O(D2O)
systems at temperatures up to 420∘Crdquo Chemical Geology vol451 pp 104ndash115 2017
[118] L Shang I-M Chou W Lu R C Burruss and Y ZhangldquoDetermination of diffusion coefficients of hydrogen in fusedsilica between 296 and 523 K by Raman spectroscopy and appli-cation of fused silica capillaries in studying redox reactionsrdquoGeochimica et CosmochimicaActa vol 73 no 18 pp 5435ndash54432009
[119] M Dargent J Dubessy L Truche E F Bazarkina C Nguyen-Trung and P Robert ldquoExperimental study of uranyl(VI) chlo-ride complex formation in acidic LiCl aqueous solutions underhydrothermal conditions (T = 21∘Cndash350∘C Psat) using Ramanspectroscopyrdquo European Journal ofMineralogy vol 25 no 5 pp765ndash775 2013
[120] YWanXWangWHu and I-MChou ldquoRaman spectroscopicobservations of the ion association between Mg2+ and SO2minus
4
in MgSO4-saturated droplets at temperatures of le380∘Crdquo The
Journal of Physical Chemistry A vol 119 no 34 pp 9027ndash90362015
[121] Y Wan X Wang W Hu I M Chou Y Chen and Z Xu ldquoInsitu optical and Raman spectroscopic observations of the effectsof pressure and fluid composition on liquidliquid phase separa-tion in aqueous cadmium sulfate solutions (=400∘C 50MPa)with geological and geochemical implicationsrdquo Geochimica etCosmochimica Acta vol 211 pp 133ndash152 2017
[122] W L Marshall ldquoAmorphous silica solubilitiesmdashI Behavior inaqueous sodium nitrate solutions 25ndash300∘C 0ndash6 molalrdquo Geo-chimica et Cosmochimica Acta vol 44 no 7 pp 907ndash913 1980
[123] C-T A Chen andW LMarshall ldquoAmorphous silica solubilitiesIV Behavior in pure water and aqueous sodium chloridesodium sulfate magnesium chloride and magnesium sulfatesolutions up to 350∘Crdquo Geochimica et Cosmochimica Acta vol46 no 2 pp 279ndash287 1982
[124] B A Fleming and D A Crerar ldquoSilicic acid ionization and cal-culation of silica solubility at elevated temperature and pHapplication to geothermal fluid processing and reinjectionrdquoGeothermics vol 11 no 1 pp 15ndash29 1982
Figure 1 Setup for in situ analyses of the vapor phase within a FSCCcontaining dolomite and water
times to promote the reaction After heatingmicro-XRD andRaman spectroscopy were used to characterize the compo-sition of the quenched solid product at room temperatureThen the SEM was used to observe the morphology ofthe product The chemical composition was analyzed usingEDS
23 Analytical Methods Raman spectra were collected witha high-resolution Raman spectrometer (LabRAM HR800JYHoriba) using a 53211 nm laser from an air-cooledfrequency-doubled NdYAG laser excitation a 50x objective(Olympus) and a 1800 groovemm grating with a spectralresolution of about 1 cmminus1 An approximate 95mW laser wasfocused on the central level of the horizontal tube for vaporspectra acquisition and on the surface of the solid phase forsolid spectra acquisition Spectra were collected from 100 to1600 cmminus1 To obtain a high signal-to-noise ratio spectrumthree accumulationswere collected in denoisemode (120 s forthe vapor phase and 30 s for the solid phase) and averaged foreach spectrum Before collection the Raman spectrometerwas calibrated with the V1 band of silicon at 5202 cmminus1[50] Labspec 5 software was used for Raman spectral analy-ses
Micro-XRD investigations of the quenched reacteddolomite were carried out with a diffractometer (DmaxRapid II Rigaku) equipped with a Mo tube and a 300-120583m diameter collimator The diffractometer was operatedat 50 kV and 90mA with an angular velocity of 6∘s andan exposure time of 15min Jade 6 software was used tocharacterize the compositions of the solid phase
The morphology of the quenched reacted dolomite wasobserved using a field emission (FE) SEM (Supra55 Zeiss)with an accelerating voltage of 15 kVThe approximate chem-ical composition of the solid phase was analyzed by an EDS(Oxford Instruments Inca X-Max 150mm2) All experimentswere performed at the Institute of Energy Sciences andthe State Key Laboratory for Mineral Deposits Researchhosted in School of Earth Sciences and Engineering NanjingUniversity
In addition we calculated the Gibbs free energy of talcformation from the CaMg(CO
3)2ndashSiO2(aq)ndashH
2O system for
the PndashT conditions covered in these experiments using theHch program (version 44) and its incorporated Unithermdatabase [51]
3 Results
31 Vapor-Phase Characterization The linear CO2 moleculehas four vibrational modes a symmetric stretching mode(V1) two bending modes (2V2 V2a and V2b) and an antisym-metric stretching mode (V3) (eg [48 52 53]) The modesV1 and 2V2 are both Raman active and have a similar energy(sim1335 cmminus1) and the same symmetry species resulting ina Fermi resonance [48] Fermi resonance causes the excitedadmixed states to split into two prominent peaks an upperband at sim1388 cmminus1 and a lower band at sim1285 cmminus1 [48 54]Weak hot bands flanking the Fermi diads may also appearin the spectrum [48] Raman spectroscopy has very lowdetection limits for CO
2and thus is used frequently for CO
2
characterization in fluid inclusions [53 55ndash58]Figure 3(a) shows the Raman spectra of the vapor phase
in FSCCs containing CaMg(CO3)2ndashH2O and CaCO
3ndashH2O
after heating at 90ndash150∘C for 24 h For the FSCCs containingdolomite and water no CO2 signal was observed afterheating at le90∘C Weak but clear CO2 Fermi bands at sim1285and 1384 cmminus1 were observed after heating at 100∘C TheRaman intensity of CO
2was much stronger after heating at
150∘C than that at 100∘C (Figure 3(a)) That is to say CO2
was generated in the CaMg(CO3)2ndashSiO2ndashH2O system when
heated at ge100∘C with an experimental duration of 24 hHowever the signals of CO
2were not observed in FSCCs
containing calcite and water after heating at 100ndash200∘C for24 h Considering that a greater concentration of CO
3
2minus
dissolved from calcite than from dolomite in pure waterat temperatures of 100ndash150∘C [59 60] we suggest that theCO2from the dolomite-bearing system was generated by
decarbonation via metamorphic reaction (1) instead of thedecomposition of dissolved CO3
2minusThe intensity and wavenumber of the CO2 Fermi diad
bands varywith changes in theCO2 pressure and temperature[48 53 56] Previous studies have suggested that the Fermidiad splits increase with increasing CO2 pressure at a con-stant temperature (eg [61]) Accordingly several equationswere constructed for quantitative measurements of the CO2density based on the Fermi diad splits by using referencesamples with PCO
2gt 06 bar ([49] and references therein)
In this study the Fermi diad peak positions and splits of CO2
produced from CaMg(CO3)2ndashSiO2ndashH2O interaction were
also obtained (Table 1) However negative density values wereobtained when applying these calibration curves to quanti-tatively measure the CO
2content in the FSCC This result
indicates that only a small amount of CO2was produced
in the FSCC and that the CO2pressure was lower than 06
bar Table 2 shows the variation of the internal pressure ofa HPOC containing dolomite and water with experimentalduration Results showed that the internal pressure fluctuatedwith reaction time Consequently the exact partial pressureof CO
2generated from the metamorphic reaction (1) cannot
be obtained this should also result from the very lowPCO2
The variation in the Raman intensity of CO2 as a functionof the experimental duration can reflect the kinetics of reac-tions yieldingCO2 [57] Increasing the experimental durationcould increase the CO2 intensity (Figure 3(b))The peak areas
4 Geofluids
Pres
sure
gen
erat
or
Pressure detector
Dolomite Vapor
Mercury
HPOC in heating stage
Simplified pressure line
H2O
H2O
(a) HPOC setup
RC
IC
CICOven
Dolom
ite
H2O
SCR
(b)
Figure 2 (a) The setup for measurements of the internal pressures within a HPOC containing dolomite and water (b) the batch stainlessreactor in the oven The left schematic diagram showing the structure of the reactor SCR represents the stainless cup of the reactor RCrepresents the reactor cover IC represents internal cup and CIC represents cover of the internal cup
Upper band
Lower band
Ram
an in
tens
ity (a
u)
1250 1300 1350 14001200 1450
CO2
150∘C 24 h
100∘C 24 h
90∘C 24 h
100∘C 24 h
Raman shift (cmminus1)
CaMg(CO3)2ndashSiO2ndashH2O
CaMg(CO3)2ndashSiO2ndashH2O
CaMg(CO3)2ndashSiO2ndashH2O
CaCO3ndashSiO2ndashH2O
(a)
Upper band
Lower band
Hot band
24 h
1200 1250 1300 1350 1400 1450
41 h
8 h
2 h
200∘C
Ram
an in
tens
ity (a
u)
Raman shift (cmminus1)
(b)
Figure 3 Raman spectra of the vapor phase in FSCCs containing (a) CaCO3ndashH2O and CaMg(CO
3)2ndashH2O after heating at 90ndash150∘C for 24 h
and (b) CaMg(CO3)2ndashH2O after heating at 200∘C from 2 to 41 h
of the CO2Fermi diad bands increased with experimental
duration up to about 120 h (200∘C) before eventually levelingoff (Figure 4 Table 1) Solid-phase characterization (seeSection 32) indicated that the dolomite was unlikely torun out over the length of the experiment Consequentlythe reaction reached an equilibrium state after reaction forsim120 hThe degree of the reaction (R) can be calculated using
the ratio between the total Raman peak area of CO2at time t
(A) and that at equilibrium state (119860lowast)
119877 () = 119860119860lowasttimes 100 (2)
As shown in Figure 4 (diamonds) the slope of R decreaseswith the increase of reaction time indicating that the
Geofluids 5
Table 1 Fermi diad bands splits and peak areas of CO2generated in the FSCC containing dolomite and water at 200∘C and the calculated
degree of reaction
Reaction time (h) Fermi diads and splits (cmminus1) Peak area Degree of reaction ()aV1
V2
Δ V1
V2
V1+ V2
0 mdash mdash mdash 0 0 0 02 128521 138792 10271 31587 36662 68249 1584 128519 138777 10258 53083 77521 130604 3026 128509 13877 10261 55164 81714 136878 3168 128514 138772 10258 59966 955 155466 35910 128484 138749 10265 73141 102321 175462 40620 128551 138804 10253 90065 141902 231967 53622 128545 1388 10255 100018 148336 248354 57428 128537 138795 10258 115519 171856 287375 66440 128543 138798 10255 13279 191084 323874 74843 128566 138821 10255 127099 188707 315806 73046 128576 138823 10247 138806 19958 338386 78249 128563 138817 10254 134642 192119 326761 75560 128539 138794 10255 13706 216374 353434 81765 128562 138816 10254 143307 220862 364169 84270 128559 138814 10255 145465 217231 362696 83887 128501 138757 10256 156179 230784 386963 89492 128549 138793 10244 162326 228882 391208 904104 128573 138811 10238 17136 245737 417097 964137 128567 138804 10237 172976 258905 431881149 128526 138799 10273 174657 250163 42482159 128538 138797 10259 183627 255395 439022171 128531 138793 10262 179781 259946 439727193 128524 138777 10253 169712 268104 437816203 128537 138795 10258 17552 255508 431028213 128566 138821 10255 174085 254889 428974224 12856 138815 10255 1725 25597 42847aThe total Raman peak area of CO2 at equilibrium state is an average of those after reaction for sim120 h Then the degree of reaction can be regarded as 100when the reaction time exceeds 120 h
reaction rates decrease with the increase of experimentaldurationPCO
2 The results also showed that the reaction
rate increased with increasing temperature For example theRaman intensity of CO2 was stronger at higher temperaturewithin a given period of time (Figure 3(a))
32 Solid-Phase Characterization Figure 5 shows XRD pat-terns of the quenched solid relicts in the fused silica tubesAfter heating at 200∘C for sim20 days the talc signals wereweak However heating for 80 days produced calcite andtalc as the main phases in the solid relicts whereas dolomitesignals were hardly visible in the XRD pattern (Figure 5)
The Raman spectrum of the solid phase before heat-ing (Figure 6) showed only dolomite peaks (sim177 30051098 cmminus1 [62]) indicating that the dolostone was of highpurity consistent with the XRD analysis However in addi-tion to dolomite characteristic calcite signals (sim282 and1086 cmminus1 [63]) and talc signals (1905 3605 and 675 cmminus1[64]) appeared after heating at 200∘C for 60 days
Figure 7 shows the morphology of the solid phaseafter heating at 200∘C for 60 days The solid phase has ahoneycomb-like texture and was widely distributed in therelicts (Figures 7(a)ndash7(d)) It was identified by EDS as talc(Figure 7(c)) The talc exhibited unoriented textures becauseit formed under strain-free conditions [21] Some cylindri-cal talc also occurred along the inner surface of the FSCC(Figure 7(d)) The dolomite grains had smooth edges (Fig-ure 7(c)) indicating dissolution during heating Some prod-ucts of rhombohedral calcite (Figure 7(d)) were also presentin the solid phase which formed along with the talc via reac-tion (1)
The amount of Mg-silicate mineral produced at 150∘Cfor 40 days was below the detection limit of the micro-XRD equipment Only dolomite and a small amount ofcalcite were observed in the XRD pattern after heating at150∘C for 40 days (Figure 5) This further supports the viewthat the metamorphic reaction rate is largely dependent ontemperature Some researchers view talc as the initial meta-morphic mineral for the CaMg(CO
3)2ndashSiO2ndashH2O system
6 Geofluids
TotalDegree of reaction
0
1000
2000
3000
4000
5000
Peak
area
0
20
40
60
80
100
Deg
ree o
f rea
ctio
n (
)
40 80 120 160 200 2400Reaction time (h)
sim1285minus1
simminus1
cmcm1385
Figure 4 Raman peak areas of CO2and the degree of reaction
versus reaction time at 200∘CBlack rectangles and red circles denotethe peak areas of the lower band at sim1285 cmminus1 and the upper bandat sim1385 cmminus1 respectively Blue triangles represent the total peakareas of both bandsThe green diamonds represent the degree of thereaction Data plotted are from Table 1
971
55 384
71
302
763
1645
283
81 258
822
4894
227
84
209
05 191
20
171
96
186
99
161
981
6004 1
5216
147
07 143
701
4219
133
691
3102
129
561
2440
123
451
1777
115
181
1437
402
133
6891
266
44
288
26
253
162
3986
219
03
201
262
0639
184
751
7863
156
49 154
19
138
75
110
89
104
471
0602
TalcCalciteDolomite
452
10
10 15 20 25 30 35 4052 (∘)Mo tube
20 days
40 days150∘C
200∘C
80 days200∘C
Figure 5 X-ray patterns of the solid relicts in FSCCs containingdolomite and water after heating at 150∘C for sim40 days (lower blueline) and at 200∘C for sim20 days (middle orange line) and sim80 days(upper black line)
(eg [4ndash6]) However serpentine minerals like lizardite andchrysotile are also likely to form at low temperatures duringmetamorphism of the CaOndashMgOndashSiO
2ndashH2OndashCO
2system
especially in contact or regional metamorphic settings [65ndash67] Some researchers have even pointed out that serpentineforms at lower temperatures than talc during metamorphism
CalciteDolomite
TalcRam
an in
tens
ity (a
u)
Solid phase
400 600 800 1000 1200200Raman shift (cmminus1)
(200∘C 60 days)
Figure 6 Raman spectrum of solid relicts after heating at 200∘C for60 daysThe reference spectra of dolomite calcite and talc were alsoshown for comparison The dolomite spectrum was acquired fromthe sample before heating The calcite spectrum was acquired fromcrystalline calcite and the reference spectrum of talc was cited froman open database hosted by the Department of Geosciences at theUniversity of Arizona (RRUFF Project httprruffinfoindexphp)
Table 2 Variations in the internal pressures of the HPOC contain-ing dolomite and water with experimental duration at 200∘C
serpentine is likely to form in a low-silica environment
Geofluids 7
(a) (b)
MgOSi
Dol
(c)
Talc
CaO
C
(d)
Figure 7 SEM micrographs and EDS analyses of the solid relicts in an FSCC containing dolomite and water after heating at 200∘C for sim60days (a b) Honeycomb-like talc (c) dolomite grains with smooth edges and EDS result of talc (yellow arrow) (d) euhedral calcite formed inthe relicts (white arrow) and cylindrical talc growing on the inner surface of the tube (yellow arrow)
further introduction of SiO2 will make talc stable relativeto serpentine [70ndash73] Considering the fact that talc wascharacterized as the product of Mg-silicate mineral in the200∘C experiment via reaction (1) we speculate that whilenot detected byXRD talc also formed below 200∘C sinceCO
2
was generated during the experiment (see above)
33 Thermodynamic Calculations Due to the limits of theUnithermdatabase we used aqueous silica as the SiO
2species
that participated in the reaction Considering that the solu-bility of amorphous silica was high at elevated temperatures[74] the calculated results should approximate the conditionsof the experiments The Gibbs free energy (Δ119866) of formationfor talc from CaMg(CO3)2 aqueous SiO2 and H
2O at the
pressure and temperature of interest are given in Table 3 TheΔ119866 of reaction decreases with increasing temperature at thesaturation pressure This indicates that the reaction is morefavorable at higher temperatures The Δ119866 becomes negativeat 119879 ge 80∘C which implies that the formation of product talcfrom dolomite and a silica-rich fluid is thermodynamicallyfavored However this reaction may not commence untileven higher temperatures are reached due to the probableinitial kinetic barrier to the reaction These thermodynamiccalculations support the implication from the experimentalresults that talc formation can occur at temperatures above100∘C
4 Discussion
41 Implications for the Formation of Mg-Carbonate-HostedTalc Geologically Prochaska [18] grouped the talc depositsinto five types (1) talc related to ultramafics (eg [13ndash15]) (2)Mg-carbonate-hosted talc (eg [20 37]) (3) metamorphictalc (eg [75 76]) (4) talc related to banded iron forma-tions (mostly minnesotaite [77 78]) and (5) secondary talcdeposits [18] The most economically viable of these depositsare usually related to the metamorphic reaction between anMg-carbonate infiltrated by a silica-rich hydrothermal fluid[18 20 21 37] Intense fractures that increase the permeabilityof geological fluid flow generally develop near such deposits[18 20 21 37 38]
Investigating the formation temperature of talc canimprove our understanding of its mineralization processThis has previously been done using several methods Theseinclude microthermometric measurements of relevant fluidinclusions (eg [39 40 79]) and calculations using talcndashdolo-mite oxygen isotope thermometry assuming that themineralpairs achieve oxygen isotope equilibrium [21 36] In additionthe phase diagram of the CaOndashMgOndashSiO2ndashCO2ndashH2O sys-tem has often been referred to for evaluating the formationtemperature of talc [5 35] The diagram was establishedbased on hydrothermal experiments geological case studiesand thermodynamic calculations [4 5 43 44] However the
8 Geofluids
Table 3 The Gibbs free energies of the reaction 3CaMg(CO3)2+ 4SiO
2(aq) + H
2O = Mg
3(Si4O10)(OH)
2+ 3CaCO
3+ 3CO
2at the
temperatures of interest and their corresponding saturation pressures
Temperature (∘C) Δ119866a (kJmol) 119875satb (bar) Temperature (∘C) ΔG (kJmol) 119875sat (bar)
25 7709 0032 100 ndash7083 101450 4663 0124 110 ndash9951 143460 2771 0199 120 ndash12938 198770 0609 0312 130 ndash16032 270380 ndash1778 0474 140 ndash19223 361590 ndash4351 0702 150 ndash22502 4761aΔ119866 refers to the Gibbs free energy of the reaction b119875sat represents the corresponding saturation pressures which are calculated based on the thermodynamicmodel proposed by Zhang and Duan [45]
experiments used to chart out this systemhave been generallyconducted at gt250∘C [4 41ndash44] The reaction path of thephase diagram at low temperatures was mainly establishedthrough thermodynamic calculations implying the need fortalc forming experiments at temperatures below 250∘C
Some geological case studies attribute low talc mineral-ization temperatures (lt200∘C) derived from adjacent talc anddolomite oxygen isotope thermometry to actually reflect iso-topic disequilibrium [36] This study shows that talc depositscan still form at temperatures below 200∘C on geologicaltime scales especially if the product CO
2can be released
(cf reaction (1)) However large-scale talc mineralization ismore likely to form at higher temperatures (eg 250ndash400∘C)Firstly PCO
2controls the lower thermal limit of talc stability
The onset temperature of the transformation increases withincreasing PCO
2 because CO
2is a product of the metamor-
phic reaction (1) and its presence greatly decreases the solu-bility of SiO
2in the fluid [80] CO
2is a common component
in geological fluids and can be either released from magmas(eg [81ndash84]) or generated from the hydrothermal alterationof carbonate (eg [85ndash87]) The oxidation (eg [88]) andhydrothermal maturation of organic matter are also naturalsources of CO
2[89 90]Therefore talcmineralization should
occur at relatively high temperatures in the presence of CO2
Secondly as our results have shown the reaction rate forreaction (1) increases sharply with increasing temperaturefacilitating talc deposits to form at higher temperatures
This study can also contribute to understanding the faultweakening mechanism in the upper crust The elastic strainaccumulation along a fault can be released through a suddenseismic slip (earthquake) or aseismic creep slip [32] A lowerfrictional coefficient for a fault will facilitate stable creepweakening the fault and suppressing the occurrence of strongearthquakes [35]The frictional coefficient of a fault generallydecreases with increasing temperature [35] Therefore faultsare likely to beweakened due to high temperatures in the deepcrust but not in the cool shallow crust The pervasive distri-bution of clay minerals along faults has also been thought toweaken faults [33ndash35 91ndash94] because layered clay mineralsexhibit much lower frictional coefficients than otherminerals[95] For example talc discovered along the SanAndreas faultzone is responsible for helping in aiding slippage along thefault [35 95] As shown here dolomite could react at le200∘Cwith silica-rich fluids traveling along fault planes to form
talc and hence might be an important mechanism of faultweakening in carbonate sequences in the upper crust
42 Implications for Hydrothermal Dolomite Reservoir Re-search Carbonate rock is the main type of hydrocarbonreservoir worldwide hosting over 60 of petroleum reserves[31] Dolomite hydrocarbon reservoirs are important com-prising about half of the carbonate hydrocarbon reser-voirs worldwide [96] Recent research has suggested thathydrothermal alteration can increase the porosity and per-meability of dolomite reservoirs substantially and is animportant factor affecting the development and distributionof dolomite reservoirs [24 25 97ndash101] The Tarim basin isone of the most important petroliferous basins in China andcontains a lower Palaeozoic carbonate series which is alsoan important hydrocarbon reservoir Recent exploration hasshown that silica-rich hydrothermal fluids have infiltratedthese carbonate series improving the physical properties ofthe reservoirs considerably (eg the Shunnan area of theTarim Basin [102 103]) It has been proposed that silica-richhydrothermal fluids were transported through extensionalfaults from the deep strata to the shallow carbonate sequencewhere they migrated laterally through porous and permeablecarbonate formations (sim6670m in the Shunnan area [104])Hydrothermal fluids originating in deep basins are generallyhot Microthermometric measurements have indicated thatthe silica-rich hydrothermal fluids in the Tarim basin reachover 200∘C [101 103] Given that the lower part of the lowerPalaeozoic sequence is mainly composed of dolomite silica-rich hydrothermal fluids could react with the dolomite toform talc and thus change the physical properties of the reser-voir Recently petrologic and diagenetic research haverevealed pervasive silicification in Early Cretaceous ultra-deep water carbonate reservoirs in the Atlantic Ocean off-shore from Brazil [105] The presence of talc calcite quartzand dolomite on the thin-section scale may indicate that thedolomite was strongly corroded by a silica-rich hydrothermalfluid
Alteration of dolomite to talcwill alsomodify the porosityand permeability of carbonate hydrocarbon reservoirs [29ndash31] The silica required for the mineral alteration can be pro-vided by either silica-rich hydrothermal fluids or silica (egquartz chert and opal) within the carbonate reservoirs [106]If SiO
2derives from quartzchert in the dolomite sequences
Geofluids 9
the hydrothermal alteration would increase the porosity ofthe dolomite reservoirs McKinley et al [29] reported thatthe total volume of minerals within a dolomite reservoir canbe reduced by 13 to 17 through the reaction betweendolomite and quartz in reaction (1) In addition the reactionbetween dolomite and silica-rich hydrothermal fluids can actas an important source of CO
2 in hydrocarbon reservoirsThepresence of CO2 can lower the pH of the formation waterand thus promote the dissolution of carbonate minerals [60107 108] increasing the porosity of the reservoirs [109ndash111]However the pore throats may be blocked by the formationof talc or other clay minerals [29 112] Therefore moredetailed factors should be considered in order to unequi-vocally evaluate the effects of silica-rich hydrothermal fluidsin dolomite reservoirs
Although talc can form from the interaction betweendolomite and silica-rich fluids at low temperatures it isseldom observed in hydrocarbon reservoirs [29 31] for thefollowing two reasons (1)A large amount of CO
2can be pro-
duced by the maturation of organic matter and the reactionbetween carbonate minerals and organic acid [98 101] Thepresence of CO
2decreases the lower thermal stability field
of talc [113] (2)The reaction path is dependent on the com-position of the hydrothermal fluid For example K+ andAl3+ are also important components of geological fluidsMontmorillonite instead of talc is more likely to form inthe presence of only a small quantity of Al3+ [41] and theformation of talc can also be inhibited by K+ [29]
43 Implications for High PndashT Experiment Using Fused SilicaCapillary Tubes as Reactors FSCCs are used to constructsynthetic fluid inclusions containing organic and inorganiccomponents [46] They offer advantages such as being inertto many components especially acids and S allowing forthe convenient synthesis of fluid inclusions and facilitatingin situ optical and Raman spectroscopic observations (eg[57 114ndash117]) Fused silica tubes can tolerate relatively hightemperatures up to 600∘C and pressures up to 300MPa As aresult FSCCs are used in many research fields For examplein addition to construction of synthetic fluid inclusions[46 53 118] FSCCs were used in studying the propertiesof hydrothermal fluids as optical and Raman spectroscopiccells [115ndash117 119ndash121] FSCCs were also used as reactorsin investigating the mechanism of thermochemical sulfatereduction [114] and the decomposition of organic matter[57]
However SiO2 in the FSCC acted as a reagent in thisstudy and was partially dissolved as indicated by the pitson the inner surface of the tube (Figures 8(a)ndash8(d)) Thedissolution of silica from FSCCs containing alkali sulfatesolutions was also observed after quenching from ge350∘C(Figures 8(e) and 8(f)) The severe dissolution of fused silicacan be ascribed to three factors (1) Amorphous silica ismore soluble than quartz especially at high temperaturesIn neutral solutions its solubility increases sharply withtemperature from 100 ppm at 20∘C to 1500 ppm at 310∘C[74 122 123] (2) Under basic conditions the solubility ofamorphous silica is greatly enhanced by the ionization ofsilicic acid (H
4SiO4+ OHminus rarr H
3SiO4
minus + H2O [124]) (3)
SiO2may act as a reagent as it did in this experiment The
presence of dissolution pits will weaken the mechanicalstrength of the silica tube In addition the presence ofdissolved silica can make the system more complicated thanexpected Therefore the solubility and reactivity of silicaunder hydrothermal conditions should be evaluated beforeFSCCs are used as reactors
5 Conclusion
The reactions in the CaMg(CO3)2ndashSiO2ndashH2O system atlow temperatures were investigated using fused silica tubesas reactors Results showed that dolomite reacted with asilica-rich fluid to form talc calcite and CO2 at le200
∘Cand low PCO2 The reaction rate increased with increasingtemperature and decreased with rising PCO2Therefore hightemperature and the presence of a conduit to release CO2 willpromote the formation of talcThis experiment has importantgeological and geochemical implications(1)Theresults confirmed themechanism of talcminerali-
zation in Mg-carbonate hosted talc deposits Dolomitereacted with silica-rich hydrothermal fluids to form talccalcite and CO
2 Talc could form at le200∘C whereas pre-
vious hydrothermal experiments examining the CaOndashMgOndashSiO2ndashCO2ndashH2O system were mainly conducted at gt250∘C
However considering the effect of temperature on thereaction rate and other geological conditions massive talcdeposits are still more likely to form at higher temperaturesThe formation of talc along a fault in a Mg-carbonateformation will also weaken the fault thus preventing strongearthquakes(2) Talc in carbonate reservoirs can indicate the activity
of silica-rich hydrothermal fluids Fluid-aided alteration ofdolomite can change the physical properties of dolomitereservoirs substantially The reaction between dolomite andquartz within the carbonate can decrease the total volume ofminerals by 13ndash17 The generation of CO2 can promotethe dissolution of carbonate minerals elsewhere under theappropriate conditions increasing the porosity and perme-ability of carbonate reservoirs However talc minerals mayblock pore throats in the reservoirs Therefore additionalfactors need to be considered when evaluating the effectsof CaMg(CO
3)2ndashSiO2ndashH2O interactions on the physical
properties of carbonate reservoirs(3) The solubility and reactivity of silica should be con-
sidered when using fused silica tubes as reactors in highPndashT experiments The dissolution of silica will increase thecomplexity of the system andweaken themechanical strengthof the tube
Conflicts of Interest
The authors declare that they have no conflicts of interest
Acknowledgments
The dolomite sample was provided by Mr Chunhua ShiMisses Yang Qu Wanlu Gao and Ye Qiu helped the authorsa lot during the micro-XRD analysis and HPOC experiment
10 Geofluids
Outer surfaceInner surface
(a) (b)In
ner s
urfa
ce
(c) (d)
Inner surface
(e) (f)
Figure 8 SEM images of the inner surface of the silica tube (a) Smooth inner surface before the reaction (b) magnification of the squarearea shown in (a) (c) dissolution pits on the inner surface after heating at 200∘C for sim60 days (d) magnification of (c) severe erosion of thesilica on the inner surface of FSCCs containing (e) 10m Na
2SO4and (f) 10m Li
2SO4after heating at 350∘C for 1 h
Dr Rui Wang and Miss Siyu Hu are also thanked for theirhelp in the thermodynamic calculations of the reactionsThis work was financially supported by the National NaturalScience Foundation of China (Grant nos 41230312 and41573054) I-Ming Chou is thankful for the support of theKnowledge Innovation Program (SIDSSE-201302) and theHadal-trench Research Program (XDB06060100) of ChineseAcademy of Sciences
References
[1] L D Meinert ldquoSkarns and skarn depositsrdquo Geoscience Canadavol 19 no 4 pp 145ndash162 1992
[2] L D Meinert G M Dipple and S Nicolescu ldquoWorld skarndepositsrdquo Economic Geology 100th Anniversary Volume pp299ndash336 2005
[3] Y Yao J Chen J Lu R Wang and R Zhang ldquoGeology andgenesis of the Hehuaping magnesian skarn-type cassiterite-sulfide deposit Hunan Province Southern ChinardquoOre GeologyReviews vol 58 no C pp 163ndash184 2014
[4] T M Gordon and H J Greenwood ldquoThe reaction dolomite+ quartz + water = talc + calcite + carbon dioxiderdquo AmericanJournal of Science vol 268 pp 225ndash242 1970
[5] M B Holness ldquoFluid flow paths and mechanisms of fluidinfiltration in carbonates during contact metamorphism TheBeinn an Dubhaich aureole Skyerdquo Journal of MetamorphicGeology vol 15 no 1 pp 59ndash70 1997
Geofluids 11
[6] W Heinrich S S Churakov andM Gottschalk ldquoMineral-fluidequilibria in the system CaOndashMgOndashSiO
2ndashH2OndashCO
2ndashNaCl
and the record of reactive fluid flow in contact metamorphicaureolesrdquo Contributions to Mineralogy and Petrology vol 148no 2 pp 131ndash149 2004
[7] M Wesołowski ldquoThermal decomposition of talc a reviewrdquoThermochimica Acta vol 78 no 1-3 pp 395ndash421 1984
[8] L A Perez-Maqueda A Duran and J L Perez-RodrıguezldquoPreparation of submicron talc particles by sonicationrdquoAppliedClay Science vol 28 no 1-4 pp 245ndash255 2005
[9] R L Johnson ldquoTalcrdquoAmerican Ceramic Society Bulletin vol 71pp 818ndash820 1992
[10] R L Johnson and R L Virta ldquoTalcrdquo American Ceramic SocietyBulletin vol 79 pp 79ndash81 2000
[11] M Z Abzalov ldquoChrome-spinels in gabbro-wehrlite intrusionsof the Pechenga area Kola Peninsula Russia emphasis onalteration featuresrdquo Lithos vol 43 no 3 pp 109ndash134 1998
[12] M F El-Sharkawy ldquoTalc mineralization of ultramafic affinity inthe Eastern Desert of Egyptrdquo Mineralium Deposita vol 35 no4 pp 346ndash363 2000
[13] M Franceschelli G Carcangiu A M Caredda G CrucianiI Memmi and M Zucca ldquoTransformation of cumulate maficrocks to granulite and re-equilibration in amphibolite andgreenschist facies in NE Sardinia Italyrdquo Lithos vol 63 no 1-2pp 1ndash18 2002
[14] S G Tesalina P Nimis T Auge and V V Zaykov ldquoOriginof chromite in mafic-ultramafic-hosted hydrothermal massivesulfides from the Main Uralian Fault South Urals RussiardquoLithos vol 70 no 1-2 pp 39ndash59 2003
[15] D M Evans ldquoMetamorphic modifications of the Muremeramafic-ultramafic intrusions eastern Burundi and their effecton chromite compositionsrdquo Journal of African Earth Sciencesvol 101 pp 19ndash34 2015
[16] T Yamanaka K Maeto H Akashi et al ldquoShallow submarinehydrothermal activity with significant contribution of mag-matic water producing talc chimneys in the Wakamiko CraterofKagoshimaBay southernKyushu Japanrdquo Journal of Volcanol-ogy and Geothermal Research vol 258 pp 74ndash84 2013
[17] B Moine J P Fortune P Moreau and F Viguier ldquoComparativemineralogy geochemistry and conditions of formation of twometasomatic talc and chlorite deposits Trimouns PyreneesFrance and Rabenwald eastern Alps Austriardquo Economic Geol-ogy vol 84 no 5 pp 1398ndash1416 1989
[18] W Prochaska ldquoGeochemistry and genesis of Austrian talcdepositsrdquo Applied Geochemistry vol 4 no 5 pp 511ndash525 1989
[19] P de Parseval S Jiang F Fontan R Wang F Martin and JFreeet ldquoGeology and ore genesis of the Trimouns talc-chloriteore deposit Pyrenees Francerdquo Acta Petrologica Sinica vol 20no 4 pp 877ndash886 2004
[20] A C Gondim and S Jiang ldquoGeologic characteristics and gene-ticmodels for the talc deposits in Parana andBahia BrazilrdquoActaPetrologica Sinica vol 20 no 4 pp 829ndash836 2004
[21] P Boulvais P de Parseval A DrsquoHulst and P Paris ldquoCarbonatealteration associated with talc-chlorite mineralization in theeastern Pyrenees with emphasis on the St Barthelemy MassifrdquoMineralogy and Petrology vol 88 no 3-4 pp 499ndash526 2006
[22] G R Davies and L B Smith Jr ldquoStructurally controlled hydro-thermal dolomite reservoir facies an overviewrdquoAAPG Bulletinvol 90 no 11 pp 1641ndash1690 2006
[23] J Lonnee and H G Machel ldquoPervasive dolomitization withsubsequent hydrothermal alteration in theClarke Lake gas field
Middle Devonian Slave Point Formation British ColumbiaCanadardquo AAPG Bulletin vol 90 no 11 pp 1739ndash1761 2006
[24] J A Luczaj ldquoEvidence against the Dorag (mixing-zone) modelfor dolomitization along theWisconsin arch - A case for hydro-thermal diagenesisrdquo AAPG Bulletin vol 90 no 11 pp 1719ndash1738 2006
[25] L B Smith Jr ldquoOrigin and reservoir characteristics of UpperOrdovician Trenton-Black River hydrothermal dolomite reser-voirs in New YorkrdquoAAPG Bulletin vol 90 no 11 pp 1691ndash17182006
[26] J Parnell ldquoDevonianMagadi-type cherts in theOrcadian BasinScotlandrdquo Journal of Sedimentary Petrology vol 56 no 4 pp495ndash500 1986
[27] J M Garcıa-Ruiz ldquoCarbonate precipitation into alkaline silica-rich environmentsrdquo Geology vol 26 no 9 pp 843ndash846 1998
[28] J Zhang W Hu Y Qian et al ldquoFormation of saddle dolomitesin Upper Cambrian carbonates western Tarim Basin (north-west China) implications for fault-related fluid flowrdquo Marineand Petroleum Geology vol 26 no 8 pp 1428ndash1440 2009
[29] J M McKinley R H Worden and A H Ruffell ldquoContactdiagenesis the effect of an intrusion on reservoir quality in thetriassic sherwood sandstone group Northern Irelandrdquo Journalof Sedimentary Research vol 71 no 3 pp 484ndash495 2001
[30] S Dong D Chen H Qing et al ldquoHydrothermal alteration ofdolostones in the Lower Ordovician Tarim Basin NW Chinamultiple constraints from petrology isotope geochemistry andfluid inclusion microthermometryrdquo Marine and PetroleumGeology vol 46 pp 270ndash286 2013
[31] V Madrucci C W D D Anjos R A Spadini D B Alvesand S M C Anjos ldquoAuthigenic magnesian clays in carbonatereservoirs in Brazilrdquo in Proceedings of the 15th International ClayConference Rio De Janeiro Brazil 2013
[32] C H Scholz ldquoEarthquakes and friction lawsrdquo Nature vol 391no 6662 pp 37ndash42 1998
[33] A M Schleicher B A Van Der Pluijm J G Solum andL N Warr ldquoOrigin and significance of clay-coated fracturesin mudrock fragments of the SAFOD borehole (ParkfieldCalifornia)rdquoGeophysical Research Letters vol 33 no 16 ArticleID L16313 2006
[34] A M Schleicher B A van der Pluijm and L N Warr ldquoNano-coatings of clay and creep of the San Andreas fault at ParkfieldCaliforniardquo Geology vol 38 no 7 pp 667ndash670 2010
[35] C Collettini C Viti S A F Smith and R E HoldsworthldquoDevelopment of interconnected talc networks and weakeningof continental low-angle normal faultsrdquo Geology vol 37 no 6pp 567ndash570 2009
[36] F Tornos and B F Spiro ldquoThe geology and isotope geochem-istry of the talc deposits of Puebla de Lillo (Cantabrian zonenorthern Spain)rdquo Economic Geology vol 95 no 6 pp 1277ndash1296 2000
[37] L Hecht R Freiberger H A Gilg G Grundmann and Y AKostitsyn ldquoRare earth element and isotope (C O Sr) charac-teristics of hydrothermal carbonates genetic implications fordolomite-hosted talc mineralization at Gopfersgrun (Fichtelge-birge Germany)rdquo Chemical Geology vol 155 no 1-2 pp 115ndash130 1999
[38] R Sharma P Joshi and P D Pant ldquoThe role of fluids inthe formation of talc deposits of Rema area Kumaun LesserHimalayardquo Journal of the Geological Society of India vol 73 no2 pp 237ndash248 2009
12 Geofluids
[39] P De Parseval B Moine J P Fortune and J Ferret ldquoFluid-mineral interactions at the origin of the Trimouns talc andchlorite deposit (Pyrenees France)rdquo in Current Research inGeology Applied to Ore Deposits P Fenoll Hach-Ali J Torrez-Ruiz and F Gervilla Eds pp 205ndash209 University of GranadaGranada Granada Spain 1993
[40] M C Boiron P Boulvais M Cathelineau D Banks N Cal-vayrac and G Hubert ldquoFluid circulation at the origin of thetrimouns talc deposit (Pyrenees France)rdquo in Proceedings of the18th Meeting of European Current Research on Fluid InclusionsSiena Italy 2005
[41] P Bayliss andA A Levhinson ldquoLow temperature hydrothermalsynthesis from dolomite or calcite quartz and kaoliniterdquo Claysand Clay Minerals vol 19 no 2 pp 109ndash114 1971
[42] G Skippen ldquoAn experimental model for low pressure meta-morphism of siliceous dolomitic marblerdquo American Journal ofScience vol 274 no 5 pp 487ndash509 1974
[43] J Slaughter D M Kerrick and V J Wall ldquoExperimen-tal and thermodynamic study of equilibria in the systemCaOndashMgOndashSiO
2ndashH2OndashCO
2rdquoAmerican Journal of Science vol
275 pp 143ndash162 1975[44] R G Eggert and D M Kerrick ldquoMetamorphic equilibria in the
siliceous dolomite system 6 kbar experimental data and geo-logic implicationsrdquo Geochimica et Cosmochimica Acta vol 45no 7 pp 1039ndash1049 1981
[45] Z Zhang and Z Duan ldquoPrediction of the PVT properties ofwater over wide range of temperatures and pressures frommolecular dynamics simulationrdquo Physics of the Earth andPlanetary Interiors vol 149 no 3-4 pp 335ndash354 2005
[46] I-M Chou Y Song and R C Burruss ldquoA newmethod for syn-thesizing fluid inclusions in fused silica capillaries containingorganic and inorganic materialrdquo Geochimica et CosmochimicaActa vol 72 no 21 pp 5217ndash5231 2008
[47] I-M Chou R C Burruss and W J Lu ldquoA new optical cellfor spectroscopic studies of geologic fluids at pressures up to100MPardquo in Advances in High-Pressure Technology for Geo-physical Applications J Chen YWang T S Duffy G Shen andL F Dobrzhinetakaya Eds pp 475ndash485 Elsevier AmsterdamNetherlands 2005
[48] K M Rosso and R J Bodnar ldquoMicrothermometric and Ramanspectroscopic detection limits of CO
2in fluid inclusions and the
Raman spectroscopic characterization of CO2rdquo Geochimica et
Cosmochimica Acta vol 59 no 19 pp 3961ndash3975 1995[49] H M Lamadrid Geochemistry of fluid-rock processes [Doctoral
dissertation] Virginia Polytechnic Institute and State Univer-sity Blacksburg VA USA 2016
[50] J H Parker D W Feldman and M Ashkin ldquoRaman scatteringby silicon and germaniumrdquo Physical Review vol 155 no 3 pp712ndash714 1967
[51] Y V Shvarov ldquoAlgorithmization of the numeric equilibriummodeling of dynamic geochemical processesrdquo GeochemistryInternational vol 37 no 6 pp 571ndash576 1999
[52] R B Wright and C H Wang ldquoDensity effect on the Fermiresonance in gaseous CO
2by Raman scatteringrdquoThe Journal of
Chemical Physics vol 58 no 7 pp 2893ndash2895 1973[53] XWang I-M ChouWHu R C Burruss Q Sun and Y Song
ldquoRaman spectroscopic measurements of CO2density experi-
mental calibration with high-pressure optical cell (HPOC) andfused silica capillary capsule (FSCC) with application to fluidinclusion observationsrdquo Geochimica et Cosmochimica Acta vol75 no 14 pp 4080ndash4093 2011
[54] H R Gordon and T K McCubbin Jr ldquoThe 28-micron bandsof CO
2rdquo Journal of Molecular Spectroscopy vol 19 no 1ndash4 pp
137ndash154 1966[55] T Azbej M J Severs B G Rusk and R J Bodnar ldquoIn situ
quantitative analysis of individual H2O-CO
2fluid inclusions by
laser Raman spectroscopyrdquo Chemical Geology vol 237 no 3-4pp 255ndash263 2007
[56] Y Song I M Chou W Hu B Robert and W Lu ldquoCO2
density-raman shift relation derived from synthetic inclusionsin fused silica capillaries and its applicationrdquo Acta GeologicaSinica (English Edition) vol 83 pp 932ndash938 2009
[57] Z Pan I-M Chou and R C Burruss ldquoHydrolysis of polycar-bonate in sub-critical water in fused silica capillary reactor within situ Raman spectroscopyrdquo Green Chemistry vol 11 no 8 pp1105ndash1107 2009
[58] M L Frezzotti F Tecce and A Casagli ldquoRaman spectroscopyfor fluid inclusion analysisrdquo Journal of Geochemical Explorationvol 112 pp 1ndash20 2012
[59] E L Shock and H C Helgeson ldquoCalculation of the thermo-dynamic and transport properties of aqueous species at highpressures and temperatures correlation algorithms for ionicspecies and equation of state predictions to 5 kb and 1000∘CrdquoGeochimica et Cosmochimica Acta vol 52 no 8 pp 2009ndash20361988
[60] O S Pokrovsky SVGolubev J Schott andACastillo ldquoCalcitedolomite and magnesite dissolution kinetics in aqueous solu-tions at acid to circumneutral pH 25 to 150∘C and 1 to 55 atmpCO2 New constraints on CO
2sequestration in sedimentary
basinsrdquo Chemical Geology vol 265 no 1-2 pp 20ndash32 2009[61] YGarrabos R Tufeu B LeNeindre G Zalczer andD Beysens
ldquoRayleigh andRaman scattering near the critical point of carbondioxiderdquo The Journal of Chemical Physics vol 72 no 8 pp4637ndash4651 1979
[62] J H Nicola J F Scott R M Couto andMM Correa ldquoRamanspectra of dolomite [CaMg(CO
3)2]rdquo Physical Review B vol 14
no 10 pp 4676ndash4678 1976[63] S Gunasekaran G Anbalagan and S Pandi ldquoRaman and
infrared spectra of carbonates of calcite structurerdquo Journal ofRaman Spectroscopy vol 37 no 9 pp 892ndash899 2006
[64] G J Rosasco and J J Blaha ldquoRaman microprobe spectra andvibrationalmode assignments of talcrdquoApplied Spectroscopy vol34 no 2 pp 140ndash144 1980
[65] V Trommsdorff and B W Evans ldquoAntigorite-ophicarbo-nates phase relations in a portion of the system CaOndashMgOndashSiO2ndashH2OndashCO
2rdquo Contributions to Mineralogy and Petrology
vol 60 no 1 pp 39ndash56 1977[66] V Trommsdorff and J A D Connolly ldquoConstraints on phase
diagram topology for the systemCaOndashMgOndashSiO2ndashCO2ndashH2Ordquo
Contributions to Mineralogy and Petrology vol 104 no 1 pp 1ndash7 1990
[67] B S Van Gosen H A Lowers S J Sutley and C A GentldquoUsing the geologic setting of talc deposits as an indicator ofamphibole asbestos contentrdquo Environmental Geology vol 45no 7 pp 920ndash939 2004
[68] W Johannes ldquoAn experimental investigation of the systemMgO-SiO
2-H2O-CO
2rdquo American Journal of Science vol 267
no 9 pp 1083ndash1104 1969[69] E S Schandl and M P Gorton ldquoHydrothermal alteration and
CO2metasomatism (natural carbon sequestration) of komati-
ites in the south-western Abitibi greenstone beltrdquo CanadianMineralogist vol 50 no 1 pp 129ndash146 2012
Geofluids 13
[70] B W Evans and S Guggenheim ldquoTalc phyrophyllite andrelated mineralsrdquo in Reviews in Mineralogy S W Bailey Edvol 19 pp 225ndash294 1988
[71] B Velde ldquoExperimental pseudomorphism of diopside by talcand serpentine in (Ni Mg)Cl
2aqueous solutionsrdquo Geochimica
et Cosmochimica Acta vol 52 no 2 pp 415ndash424 1988[72] A E Williams-Jones C Normand H Clark Vali Jr R F
Martin A Dufresne and Nayebzadeh A ldquoControls of amphi-bole formation in chrysotile from the Jeffrey Mine AsbestosQuebecrdquo inTheHealth Effects Effects of Chrysotile Asbestos R PNolan AM LangerM RossWicks F J andMartin F R Edsvol 5 pp 89ndash104 The Mineralogical Association of CanadaQuebec Quebec Canada 2001
[73] B W Evans ldquoThe serpentinite multisystem revisited chrysotileis metastablerdquo International Geology Review vol 46 no 6 pp479ndash506 2004
[74] I Gunnarsson and S Arnorsson ldquoAmorphous silica solubilityand the thermodynamic properties of H
4SiO∘4in the range of
0∘ to 350∘C at Psatrdquo Geochimica et Cosmochimica Acta vol 64no 13 pp 2295ndash2307 2000
[75] M W Bodine Jr ldquoTrioctahedral clay mineral assemblages inPaleozoic marine evaporite rocksrdquo in Proceedings of the Pre-sented in the Sixth International Symposium on Salt vol 1 pp267ndash284 Toronto Canada 1983
[76] W Schreyer and K Abraham ldquoThree-stage metamorphic his-tory of a whiteschist from Sar e Sang Afghanistan as part ofa former evaporite depositrdquo Contributions to Mineralogy andPetrology vol 59 no 2 pp 111ndash130 1976
[77] T Angerer and S G Hagemann ldquoThe BIF-hosted high-gradeiron ore deposits in the archean koolyanobbing greenstonebelt Western Australia structural control on synorogenic-and weathering-related magnetite- hematite- and goethite-rich iron orerdquo Economic Geology vol 105 no 5 pp 917ndash9452010
[78] P Duuring and S Hagemann ldquoLeaching of silica bands andconcentration of magnetite in Archean BIF by hypogene fluidsBeebyn Fe ore deposit Yilgarn Craton Western AustraliardquoMineralium Deposita vol 48 no 3 pp 341ndash370 2013
[79] D Shin and I Lee ldquoFluid inclusions and their stable isotopegeochemistry of the carbonate-hosted talc deposits near theCretaceous Muamsa Granite South Koreardquo Geochemical Jour-nal vol 40 no 1 pp 69ndash85 2006
[80] P G Novgorodov ldquoSolubility of quartz in anH2OndashCO
2mixture
at 700 degrees C and pressures of 3 and 5 kbarsrdquoGeokhimiya pp1484ndash1489 1975
[81] T M Gerlach ldquoChemical characteristics of the volcanic gasesfrom Nyiragongo lava lake and the generation of CH
4-rich
fluid inclusions in alkaline rocksrdquo Journal of Volcanology ampGeothermal Research vol 8 no 2-4 pp 177ndash189 1980
[82] J V Walther and P M Orville ldquoVolatile production and trans-port in regional metamorphismrdquo Contributions to Mineralogyand Petrology vol 79 no 3 pp 252ndash257 1982
[83] W F Giggenbach ldquoThe origin and evolution of fluids inmagmatic-hydrothermal systemsrdquo in Geochemistry of Hydro-thermalOreDeposits H L Barnes Ed pp 737ndash796WileyNewYork NY USA 3 edition 1997
[84] J B Lowenstern ldquoCarbon dioxide in magmas and implicationsfor hydrothermal systemsrdquoMineralium Deposita vol 36 no 6pp 490ndash502 2001
[85] R Kerrich and W S Fyfe ldquoThe gold-carbonate associationsource of CO
2 and CO
2fixation reactions in Archaean lode
depositsrdquo Chemical Geology vol 33 no 1ndash4 pp 265ndash294 1981
[86] P I Nabelek ldquoCalc-silicate reactions and bedding-controlledisotopic exchange in the Notch Peak aureole Utah implicationsfor differential fluid fluxes with metamorphic graderdquo Journal ofMetamorphic Geology vol 20 no 4 pp 429ndash440 2002
[87] P I Nabelek ldquoFluid evolution and kinetics of metamorphicreactions in calc-silicate contact aureoles - From H
2O to CO
2
and backrdquo Geology vol 35 no 10 pp 927ndash930 2007[88] H G Machel ldquoBacterial and thermochemical sulfate reduction
in diagenetic settings - old and new insightsrdquo SedimentaryGeology vol 140 no 1-2 pp 143ndash175 2001
[89] L Stalker P Farrimond and S R Larter ldquoWater as an oxygensource for the production of oxygenated compounds (includingCO2precursors) during kerogen maturationrdquo Organic Geo-
chemistry vol 22 no 3-5 pp 477ndashIN4 1994[90] Z K Shipton J P Evans D Kirschner P T Kolesar A P
Williams and J Heath ldquoAnalysis of CO2leakage through lsquolow-
permeabilityrsquo faults from natural reservoirs in the ColoradoPlateau east-central Utahrdquo Geological Society Special Publica-tion vol 233 pp 43ndash58 2004
[91] J Byerlee ldquoFriction overpressure and fault normal compres-sionrdquo Geophysical Research Letters vol 17 no 12 pp 2109ndash21121990
[92] C Morrow B Radney and J Byerlee ldquoChapter 3 frictionalstrength and the effective pressure law of montmorillonite andlllite claysrdquo International Geophysics vol 51 no C pp 69ndash881992
[93] C A Morrow D E Moore and D A Lockner ldquoThe effectof mineral bond strength and adsorbed water on fault gougefrictional strengthrdquo Geophysical Research Letters vol 27 no 6pp 815ndash818 2000
[94] D A Lockner C Morrow D Moore and S Hickman ldquoLowstrength of deep San Andreas fault gouge from SAFOD corerdquoNature vol 472 no 7341 pp 82ndash86 2011
[95] D EMoore andM J Rymer ldquoTalc-bearing serpentinite and thecreeping section of the San Andreas faultrdquo Nature vol 448 no7155 pp 795ndash797 2007
[96] DH Zenger ldquoDiscussion lsquoOn the formation and occurrence ofsaddle dolomitersquordquo Journal of Sedimentary Petrology vol 51 no4 pp 1350ndash1352 1981
[97] DAKatzG P Eberli P K Swart andL B Smith Jr ldquoTectonic-hydrothermal brecciation associated with calcite precipitationand permeability destruction in Mississippian carbonate reser-voirs Montana and Wyomingrdquo AAPG Bulletin vol 90 no 11pp 1803ndash1841 2006
[98] M Esteban and C Taberner ldquoSecondary porosity developmentduring late burial in carbonate reservoirs as a result of mixingandor cooling of brinesrdquo Journal of Geochemical Explorationvol 78-79 pp 355ndash359 2003
[99] H G MacHel ldquoInvestigations of burial diagenesis in carbonatehydrocarbon reservoir rocksrdquoGeoscience Canada vol 32 no 3pp 103ndash128 2005
[100] J A Sagan and B S Hart ldquoThree-dimensional seismic-baseddefinition of fault-related porosity development Trenton-BlackRiver interval Saybrook Ohiordquo AAPG Bulletin vol 90 no 11pp 1763ndash1785 2006
[101] F Xing and S Li ldquoGenesis and environment characteristics ofdolomite-hosted quartz and its significance for hydrocarbonexploration in Keping Area Tarim Basin Chinardquo Journal ofEarth Science vol 23 no 4 pp 476ndash489 2012
[102] L Yun and Z Cao ldquoHydrocarbon enrichment pattern andexploration potential of the Ordovician in Shunnan area TarimBasinrdquo Oil and Gas Geology vol 35 no 6 pp 788ndash797 2014
14 Geofluids
[103] Y Li N Ye X Yuan Q Huang B Su and R Zhou ldquoGeologicaland geochemical characteristics of silicified hydrothermal fluidsin Well Shunnan 4 Tarim Basinrdquo Oil and Gas Geology vol 36no 6 pp 934ndash944 2015
[104] L Qi ldquoOil and gas breakthrough in ultra-deep Ordoviciancarbonate formations in Shuntuoguole uplift Tarim BasinrdquoChina Petroleum Exploration vol 21 no 3 pp 38ndash51 2016 (inChinese with English abstract)
[105] H R Qing ldquoAn introduction of petrology and diagenesis ofultra-deep water carbonate reservoirs from the Atlantic Oceanoffshore Brazilrdquo 2017 Oral presentation at Wuxi Institute ofPetroleum Geology of SINOPEC Wuxi China
[106] G J Simandl and S Paradisl ldquoCarbonate-hosted talcrdquo SelectedBritish ColumbiaMineral Deposit Profiles vol 3 pp 35ndash38 1999
[107] Y K Kharaka D R Cole S D Hovorka W D Gunter K GKnauss and BM Freifeld ldquoGas-water-rock interactions in FrioFormation following CO
2injection implications for the storage
of greenhouse gases in sedimentary basinsrdquoGeology vol 34 no7 pp 577ndash580 2006
[108] Z Duan and D Li ldquoCoupled phase and aqueous speciesequilibrium of the H
2OndashCO
2ndashNaClndashCaCO
3system from 0 to
250∘C 1 to 1000 bar with NaCl concentrations up to saturationof haliterdquo Geochimica et Cosmochimica Acta vol 72 no 20 pp5128ndash5145 2008
[109] M R Giles and J DMarshall ldquoConstraints on the developmentof secondary porosity in the subsurface re-evaluation of pro-cessesrdquoMarine and PetroleumGeology vol 3 no 3 pp 243ndash2551986
[110] O S Pokrovsky S V Golubev and J Schott ldquoDissolution kinet-ics of calcite dolomite and magnesite at 25∘C and 0 to 50 atmpCO2rdquo Chemical Geology vol 217 no 3-4 pp 239ndash255 2005
[111] P Cao Z T Karpyn and L Li ldquoThe role of host rock pro-perties in determining potential CO
2migration pathwaysrdquo
International Journal of Greenhouse Gas Control vol 45 pp 18ndash26 2016
[112] M D Fishburn ldquoSignificant results of deep drilling at ElkHills Kern County Californiardquo in Structure Stratigraphy andHydrocarbon Occurrences of the San Joaquin Basin CaliforniaG K Kuespert and S A Reid Eds vol 64 pp 157ndash167 PacificSections Society of Economic Paleontologists and Mineralo-gists and American Association of Petroleum Geologists 1990
[113] E Povoden M Horacek and R Abart ldquoContact metamor-phism of siliceous dolomite and impure limestones from theWerfen formation in the eastern Monzoni contact aureolerdquoMineralogy and Petrology vol 76 no 1-2 pp 99ndash120 2002
[114] S Yuan I-M Chou R C Burruss X Wang and J Li ldquoDispro-portionation and thermochemical sulfate reduction reactions inSndashH2OndashCH
4and SndashD
2OndashCH
4systems from 200 to 340∘C at
elevated pressuresrdquo Geochimica et Cosmochimica Acta vol 118pp 263ndash275 2013
[115] X Wang I-M Chou W Hu and R C Burruss ldquoIn situ obser-vations of liquid-liquid phase separation in aqueous MgSO
4
solutions geological and geochemical implicationsrdquo Geochim-ica et Cosmochimica Acta vol 103 pp 1ndash10 2013
[116] X Wang Y Wan W Hu et al ldquoIn situ observations of liquid-liquid phase separation in aqueous ZnSO
4solutions at tem-
peratures up to 400∘C Implications for Zn2+ndashSO2minus4
[117] X Wang IM Chou W Hu Y Wan and Z Li ldquoPropertiesof lithium under hydrothermal conditions revealed by in situ
Raman spectroscopic characterization of Li2O-SO
3-H2O(D2O)
systems at temperatures up to 420∘Crdquo Chemical Geology vol451 pp 104ndash115 2017
[118] L Shang I-M Chou W Lu R C Burruss and Y ZhangldquoDetermination of diffusion coefficients of hydrogen in fusedsilica between 296 and 523 K by Raman spectroscopy and appli-cation of fused silica capillaries in studying redox reactionsrdquoGeochimica et CosmochimicaActa vol 73 no 18 pp 5435ndash54432009
[119] M Dargent J Dubessy L Truche E F Bazarkina C Nguyen-Trung and P Robert ldquoExperimental study of uranyl(VI) chlo-ride complex formation in acidic LiCl aqueous solutions underhydrothermal conditions (T = 21∘Cndash350∘C Psat) using Ramanspectroscopyrdquo European Journal ofMineralogy vol 25 no 5 pp765ndash775 2013
[120] YWanXWangWHu and I-MChou ldquoRaman spectroscopicobservations of the ion association between Mg2+ and SO2minus
4
in MgSO4-saturated droplets at temperatures of le380∘Crdquo The
Journal of Physical Chemistry A vol 119 no 34 pp 9027ndash90362015
[121] Y Wan X Wang W Hu I M Chou Y Chen and Z Xu ldquoInsitu optical and Raman spectroscopic observations of the effectsof pressure and fluid composition on liquidliquid phase separa-tion in aqueous cadmium sulfate solutions (=400∘C 50MPa)with geological and geochemical implicationsrdquo Geochimica etCosmochimica Acta vol 211 pp 133ndash152 2017
[122] W L Marshall ldquoAmorphous silica solubilitiesmdashI Behavior inaqueous sodium nitrate solutions 25ndash300∘C 0ndash6 molalrdquo Geo-chimica et Cosmochimica Acta vol 44 no 7 pp 907ndash913 1980
[123] C-T A Chen andW LMarshall ldquoAmorphous silica solubilitiesIV Behavior in pure water and aqueous sodium chloridesodium sulfate magnesium chloride and magnesium sulfatesolutions up to 350∘Crdquo Geochimica et Cosmochimica Acta vol46 no 2 pp 279ndash287 1982
[124] B A Fleming and D A Crerar ldquoSilicic acid ionization and cal-culation of silica solubility at elevated temperature and pHapplication to geothermal fluid processing and reinjectionrdquoGeothermics vol 11 no 1 pp 15ndash29 1982
Figure 2 (a) The setup for measurements of the internal pressures within a HPOC containing dolomite and water (b) the batch stainlessreactor in the oven The left schematic diagram showing the structure of the reactor SCR represents the stainless cup of the reactor RCrepresents the reactor cover IC represents internal cup and CIC represents cover of the internal cup
Upper band
Lower band
Ram
an in
tens
ity (a
u)
1250 1300 1350 14001200 1450
CO2
150∘C 24 h
100∘C 24 h
90∘C 24 h
100∘C 24 h
Raman shift (cmminus1)
CaMg(CO3)2ndashSiO2ndashH2O
CaMg(CO3)2ndashSiO2ndashH2O
CaMg(CO3)2ndashSiO2ndashH2O
CaCO3ndashSiO2ndashH2O
(a)
Upper band
Lower band
Hot band
24 h
1200 1250 1300 1350 1400 1450
41 h
8 h
2 h
200∘C
Ram
an in
tens
ity (a
u)
Raman shift (cmminus1)
(b)
Figure 3 Raman spectra of the vapor phase in FSCCs containing (a) CaCO3ndashH2O and CaMg(CO
3)2ndashH2O after heating at 90ndash150∘C for 24 h
and (b) CaMg(CO3)2ndashH2O after heating at 200∘C from 2 to 41 h
of the CO2Fermi diad bands increased with experimental
duration up to about 120 h (200∘C) before eventually levelingoff (Figure 4 Table 1) Solid-phase characterization (seeSection 32) indicated that the dolomite was unlikely torun out over the length of the experiment Consequentlythe reaction reached an equilibrium state after reaction forsim120 hThe degree of the reaction (R) can be calculated using
the ratio between the total Raman peak area of CO2at time t
(A) and that at equilibrium state (119860lowast)
119877 () = 119860119860lowasttimes 100 (2)
As shown in Figure 4 (diamonds) the slope of R decreaseswith the increase of reaction time indicating that the
Geofluids 5
Table 1 Fermi diad bands splits and peak areas of CO2generated in the FSCC containing dolomite and water at 200∘C and the calculated
degree of reaction
Reaction time (h) Fermi diads and splits (cmminus1) Peak area Degree of reaction ()aV1
V2
Δ V1
V2
V1+ V2
0 mdash mdash mdash 0 0 0 02 128521 138792 10271 31587 36662 68249 1584 128519 138777 10258 53083 77521 130604 3026 128509 13877 10261 55164 81714 136878 3168 128514 138772 10258 59966 955 155466 35910 128484 138749 10265 73141 102321 175462 40620 128551 138804 10253 90065 141902 231967 53622 128545 1388 10255 100018 148336 248354 57428 128537 138795 10258 115519 171856 287375 66440 128543 138798 10255 13279 191084 323874 74843 128566 138821 10255 127099 188707 315806 73046 128576 138823 10247 138806 19958 338386 78249 128563 138817 10254 134642 192119 326761 75560 128539 138794 10255 13706 216374 353434 81765 128562 138816 10254 143307 220862 364169 84270 128559 138814 10255 145465 217231 362696 83887 128501 138757 10256 156179 230784 386963 89492 128549 138793 10244 162326 228882 391208 904104 128573 138811 10238 17136 245737 417097 964137 128567 138804 10237 172976 258905 431881149 128526 138799 10273 174657 250163 42482159 128538 138797 10259 183627 255395 439022171 128531 138793 10262 179781 259946 439727193 128524 138777 10253 169712 268104 437816203 128537 138795 10258 17552 255508 431028213 128566 138821 10255 174085 254889 428974224 12856 138815 10255 1725 25597 42847aThe total Raman peak area of CO2 at equilibrium state is an average of those after reaction for sim120 h Then the degree of reaction can be regarded as 100when the reaction time exceeds 120 h
reaction rates decrease with the increase of experimentaldurationPCO
2 The results also showed that the reaction
rate increased with increasing temperature For example theRaman intensity of CO2 was stronger at higher temperaturewithin a given period of time (Figure 3(a))
32 Solid-Phase Characterization Figure 5 shows XRD pat-terns of the quenched solid relicts in the fused silica tubesAfter heating at 200∘C for sim20 days the talc signals wereweak However heating for 80 days produced calcite andtalc as the main phases in the solid relicts whereas dolomitesignals were hardly visible in the XRD pattern (Figure 5)
The Raman spectrum of the solid phase before heat-ing (Figure 6) showed only dolomite peaks (sim177 30051098 cmminus1 [62]) indicating that the dolostone was of highpurity consistent with the XRD analysis However in addi-tion to dolomite characteristic calcite signals (sim282 and1086 cmminus1 [63]) and talc signals (1905 3605 and 675 cmminus1[64]) appeared after heating at 200∘C for 60 days
Figure 7 shows the morphology of the solid phaseafter heating at 200∘C for 60 days The solid phase has ahoneycomb-like texture and was widely distributed in therelicts (Figures 7(a)ndash7(d)) It was identified by EDS as talc(Figure 7(c)) The talc exhibited unoriented textures becauseit formed under strain-free conditions [21] Some cylindri-cal talc also occurred along the inner surface of the FSCC(Figure 7(d)) The dolomite grains had smooth edges (Fig-ure 7(c)) indicating dissolution during heating Some prod-ucts of rhombohedral calcite (Figure 7(d)) were also presentin the solid phase which formed along with the talc via reac-tion (1)
The amount of Mg-silicate mineral produced at 150∘Cfor 40 days was below the detection limit of the micro-XRD equipment Only dolomite and a small amount ofcalcite were observed in the XRD pattern after heating at150∘C for 40 days (Figure 5) This further supports the viewthat the metamorphic reaction rate is largely dependent ontemperature Some researchers view talc as the initial meta-morphic mineral for the CaMg(CO
3)2ndashSiO2ndashH2O system
6 Geofluids
TotalDegree of reaction
0
1000
2000
3000
4000
5000
Peak
area
0
20
40
60
80
100
Deg
ree o
f rea
ctio
n (
)
40 80 120 160 200 2400Reaction time (h)
sim1285minus1
simminus1
cmcm1385
Figure 4 Raman peak areas of CO2and the degree of reaction
versus reaction time at 200∘CBlack rectangles and red circles denotethe peak areas of the lower band at sim1285 cmminus1 and the upper bandat sim1385 cmminus1 respectively Blue triangles represent the total peakareas of both bandsThe green diamonds represent the degree of thereaction Data plotted are from Table 1
971
55 384
71
302
763
1645
283
81 258
822
4894
227
84
209
05 191
20
171
96
186
99
161
981
6004 1
5216
147
07 143
701
4219
133
691
3102
129
561
2440
123
451
1777
115
181
1437
402
133
6891
266
44
288
26
253
162
3986
219
03
201
262
0639
184
751
7863
156
49 154
19
138
75
110
89
104
471
0602
TalcCalciteDolomite
452
10
10 15 20 25 30 35 4052 (∘)Mo tube
20 days
40 days150∘C
200∘C
80 days200∘C
Figure 5 X-ray patterns of the solid relicts in FSCCs containingdolomite and water after heating at 150∘C for sim40 days (lower blueline) and at 200∘C for sim20 days (middle orange line) and sim80 days(upper black line)
(eg [4ndash6]) However serpentine minerals like lizardite andchrysotile are also likely to form at low temperatures duringmetamorphism of the CaOndashMgOndashSiO
2ndashH2OndashCO
2system
especially in contact or regional metamorphic settings [65ndash67] Some researchers have even pointed out that serpentineforms at lower temperatures than talc during metamorphism
CalciteDolomite
TalcRam
an in
tens
ity (a
u)
Solid phase
400 600 800 1000 1200200Raman shift (cmminus1)
(200∘C 60 days)
Figure 6 Raman spectrum of solid relicts after heating at 200∘C for60 daysThe reference spectra of dolomite calcite and talc were alsoshown for comparison The dolomite spectrum was acquired fromthe sample before heating The calcite spectrum was acquired fromcrystalline calcite and the reference spectrum of talc was cited froman open database hosted by the Department of Geosciences at theUniversity of Arizona (RRUFF Project httprruffinfoindexphp)
Table 2 Variations in the internal pressures of the HPOC contain-ing dolomite and water with experimental duration at 200∘C
serpentine is likely to form in a low-silica environment
Geofluids 7
(a) (b)
MgOSi
Dol
(c)
Talc
CaO
C
(d)
Figure 7 SEM micrographs and EDS analyses of the solid relicts in an FSCC containing dolomite and water after heating at 200∘C for sim60days (a b) Honeycomb-like talc (c) dolomite grains with smooth edges and EDS result of talc (yellow arrow) (d) euhedral calcite formed inthe relicts (white arrow) and cylindrical talc growing on the inner surface of the tube (yellow arrow)
further introduction of SiO2 will make talc stable relativeto serpentine [70ndash73] Considering the fact that talc wascharacterized as the product of Mg-silicate mineral in the200∘C experiment via reaction (1) we speculate that whilenot detected byXRD talc also formed below 200∘C sinceCO
2
was generated during the experiment (see above)
33 Thermodynamic Calculations Due to the limits of theUnithermdatabase we used aqueous silica as the SiO
2species
that participated in the reaction Considering that the solu-bility of amorphous silica was high at elevated temperatures[74] the calculated results should approximate the conditionsof the experiments The Gibbs free energy (Δ119866) of formationfor talc from CaMg(CO3)2 aqueous SiO2 and H
2O at the
pressure and temperature of interest are given in Table 3 TheΔ119866 of reaction decreases with increasing temperature at thesaturation pressure This indicates that the reaction is morefavorable at higher temperatures The Δ119866 becomes negativeat 119879 ge 80∘C which implies that the formation of product talcfrom dolomite and a silica-rich fluid is thermodynamicallyfavored However this reaction may not commence untileven higher temperatures are reached due to the probableinitial kinetic barrier to the reaction These thermodynamiccalculations support the implication from the experimentalresults that talc formation can occur at temperatures above100∘C
4 Discussion
41 Implications for the Formation of Mg-Carbonate-HostedTalc Geologically Prochaska [18] grouped the talc depositsinto five types (1) talc related to ultramafics (eg [13ndash15]) (2)Mg-carbonate-hosted talc (eg [20 37]) (3) metamorphictalc (eg [75 76]) (4) talc related to banded iron forma-tions (mostly minnesotaite [77 78]) and (5) secondary talcdeposits [18] The most economically viable of these depositsare usually related to the metamorphic reaction between anMg-carbonate infiltrated by a silica-rich hydrothermal fluid[18 20 21 37] Intense fractures that increase the permeabilityof geological fluid flow generally develop near such deposits[18 20 21 37 38]
Investigating the formation temperature of talc canimprove our understanding of its mineralization processThis has previously been done using several methods Theseinclude microthermometric measurements of relevant fluidinclusions (eg [39 40 79]) and calculations using talcndashdolo-mite oxygen isotope thermometry assuming that themineralpairs achieve oxygen isotope equilibrium [21 36] In additionthe phase diagram of the CaOndashMgOndashSiO2ndashCO2ndashH2O sys-tem has often been referred to for evaluating the formationtemperature of talc [5 35] The diagram was establishedbased on hydrothermal experiments geological case studiesand thermodynamic calculations [4 5 43 44] However the
8 Geofluids
Table 3 The Gibbs free energies of the reaction 3CaMg(CO3)2+ 4SiO
2(aq) + H
2O = Mg
3(Si4O10)(OH)
2+ 3CaCO
3+ 3CO
2at the
temperatures of interest and their corresponding saturation pressures
Temperature (∘C) Δ119866a (kJmol) 119875satb (bar) Temperature (∘C) ΔG (kJmol) 119875sat (bar)
25 7709 0032 100 ndash7083 101450 4663 0124 110 ndash9951 143460 2771 0199 120 ndash12938 198770 0609 0312 130 ndash16032 270380 ndash1778 0474 140 ndash19223 361590 ndash4351 0702 150 ndash22502 4761aΔ119866 refers to the Gibbs free energy of the reaction b119875sat represents the corresponding saturation pressures which are calculated based on the thermodynamicmodel proposed by Zhang and Duan [45]
experiments used to chart out this systemhave been generallyconducted at gt250∘C [4 41ndash44] The reaction path of thephase diagram at low temperatures was mainly establishedthrough thermodynamic calculations implying the need fortalc forming experiments at temperatures below 250∘C
Some geological case studies attribute low talc mineral-ization temperatures (lt200∘C) derived from adjacent talc anddolomite oxygen isotope thermometry to actually reflect iso-topic disequilibrium [36] This study shows that talc depositscan still form at temperatures below 200∘C on geologicaltime scales especially if the product CO
2can be released
(cf reaction (1)) However large-scale talc mineralization ismore likely to form at higher temperatures (eg 250ndash400∘C)Firstly PCO
2controls the lower thermal limit of talc stability
The onset temperature of the transformation increases withincreasing PCO
2 because CO
2is a product of the metamor-
phic reaction (1) and its presence greatly decreases the solu-bility of SiO
2in the fluid [80] CO
2is a common component
in geological fluids and can be either released from magmas(eg [81ndash84]) or generated from the hydrothermal alterationof carbonate (eg [85ndash87]) The oxidation (eg [88]) andhydrothermal maturation of organic matter are also naturalsources of CO
2[89 90]Therefore talcmineralization should
occur at relatively high temperatures in the presence of CO2
Secondly as our results have shown the reaction rate forreaction (1) increases sharply with increasing temperaturefacilitating talc deposits to form at higher temperatures
This study can also contribute to understanding the faultweakening mechanism in the upper crust The elastic strainaccumulation along a fault can be released through a suddenseismic slip (earthquake) or aseismic creep slip [32] A lowerfrictional coefficient for a fault will facilitate stable creepweakening the fault and suppressing the occurrence of strongearthquakes [35]The frictional coefficient of a fault generallydecreases with increasing temperature [35] Therefore faultsare likely to beweakened due to high temperatures in the deepcrust but not in the cool shallow crust The pervasive distri-bution of clay minerals along faults has also been thought toweaken faults [33ndash35 91ndash94] because layered clay mineralsexhibit much lower frictional coefficients than otherminerals[95] For example talc discovered along the SanAndreas faultzone is responsible for helping in aiding slippage along thefault [35 95] As shown here dolomite could react at le200∘Cwith silica-rich fluids traveling along fault planes to form
talc and hence might be an important mechanism of faultweakening in carbonate sequences in the upper crust
42 Implications for Hydrothermal Dolomite Reservoir Re-search Carbonate rock is the main type of hydrocarbonreservoir worldwide hosting over 60 of petroleum reserves[31] Dolomite hydrocarbon reservoirs are important com-prising about half of the carbonate hydrocarbon reser-voirs worldwide [96] Recent research has suggested thathydrothermal alteration can increase the porosity and per-meability of dolomite reservoirs substantially and is animportant factor affecting the development and distributionof dolomite reservoirs [24 25 97ndash101] The Tarim basin isone of the most important petroliferous basins in China andcontains a lower Palaeozoic carbonate series which is alsoan important hydrocarbon reservoir Recent exploration hasshown that silica-rich hydrothermal fluids have infiltratedthese carbonate series improving the physical properties ofthe reservoirs considerably (eg the Shunnan area of theTarim Basin [102 103]) It has been proposed that silica-richhydrothermal fluids were transported through extensionalfaults from the deep strata to the shallow carbonate sequencewhere they migrated laterally through porous and permeablecarbonate formations (sim6670m in the Shunnan area [104])Hydrothermal fluids originating in deep basins are generallyhot Microthermometric measurements have indicated thatthe silica-rich hydrothermal fluids in the Tarim basin reachover 200∘C [101 103] Given that the lower part of the lowerPalaeozoic sequence is mainly composed of dolomite silica-rich hydrothermal fluids could react with the dolomite toform talc and thus change the physical properties of the reser-voir Recently petrologic and diagenetic research haverevealed pervasive silicification in Early Cretaceous ultra-deep water carbonate reservoirs in the Atlantic Ocean off-shore from Brazil [105] The presence of talc calcite quartzand dolomite on the thin-section scale may indicate that thedolomite was strongly corroded by a silica-rich hydrothermalfluid
Alteration of dolomite to talcwill alsomodify the porosityand permeability of carbonate hydrocarbon reservoirs [29ndash31] The silica required for the mineral alteration can be pro-vided by either silica-rich hydrothermal fluids or silica (egquartz chert and opal) within the carbonate reservoirs [106]If SiO
2derives from quartzchert in the dolomite sequences
Geofluids 9
the hydrothermal alteration would increase the porosity ofthe dolomite reservoirs McKinley et al [29] reported thatthe total volume of minerals within a dolomite reservoir canbe reduced by 13 to 17 through the reaction betweendolomite and quartz in reaction (1) In addition the reactionbetween dolomite and silica-rich hydrothermal fluids can actas an important source of CO
2 in hydrocarbon reservoirsThepresence of CO2 can lower the pH of the formation waterand thus promote the dissolution of carbonate minerals [60107 108] increasing the porosity of the reservoirs [109ndash111]However the pore throats may be blocked by the formationof talc or other clay minerals [29 112] Therefore moredetailed factors should be considered in order to unequi-vocally evaluate the effects of silica-rich hydrothermal fluidsin dolomite reservoirs
Although talc can form from the interaction betweendolomite and silica-rich fluids at low temperatures it isseldom observed in hydrocarbon reservoirs [29 31] for thefollowing two reasons (1)A large amount of CO
2can be pro-
duced by the maturation of organic matter and the reactionbetween carbonate minerals and organic acid [98 101] Thepresence of CO
2decreases the lower thermal stability field
of talc [113] (2)The reaction path is dependent on the com-position of the hydrothermal fluid For example K+ andAl3+ are also important components of geological fluidsMontmorillonite instead of talc is more likely to form inthe presence of only a small quantity of Al3+ [41] and theformation of talc can also be inhibited by K+ [29]
43 Implications for High PndashT Experiment Using Fused SilicaCapillary Tubes as Reactors FSCCs are used to constructsynthetic fluid inclusions containing organic and inorganiccomponents [46] They offer advantages such as being inertto many components especially acids and S allowing forthe convenient synthesis of fluid inclusions and facilitatingin situ optical and Raman spectroscopic observations (eg[57 114ndash117]) Fused silica tubes can tolerate relatively hightemperatures up to 600∘C and pressures up to 300MPa As aresult FSCCs are used in many research fields For examplein addition to construction of synthetic fluid inclusions[46 53 118] FSCCs were used in studying the propertiesof hydrothermal fluids as optical and Raman spectroscopiccells [115ndash117 119ndash121] FSCCs were also used as reactorsin investigating the mechanism of thermochemical sulfatereduction [114] and the decomposition of organic matter[57]
However SiO2 in the FSCC acted as a reagent in thisstudy and was partially dissolved as indicated by the pitson the inner surface of the tube (Figures 8(a)ndash8(d)) Thedissolution of silica from FSCCs containing alkali sulfatesolutions was also observed after quenching from ge350∘C(Figures 8(e) and 8(f)) The severe dissolution of fused silicacan be ascribed to three factors (1) Amorphous silica ismore soluble than quartz especially at high temperaturesIn neutral solutions its solubility increases sharply withtemperature from 100 ppm at 20∘C to 1500 ppm at 310∘C[74 122 123] (2) Under basic conditions the solubility ofamorphous silica is greatly enhanced by the ionization ofsilicic acid (H
4SiO4+ OHminus rarr H
3SiO4
minus + H2O [124]) (3)
SiO2may act as a reagent as it did in this experiment The
presence of dissolution pits will weaken the mechanicalstrength of the silica tube In addition the presence ofdissolved silica can make the system more complicated thanexpected Therefore the solubility and reactivity of silicaunder hydrothermal conditions should be evaluated beforeFSCCs are used as reactors
5 Conclusion
The reactions in the CaMg(CO3)2ndashSiO2ndashH2O system atlow temperatures were investigated using fused silica tubesas reactors Results showed that dolomite reacted with asilica-rich fluid to form talc calcite and CO2 at le200
∘Cand low PCO2 The reaction rate increased with increasingtemperature and decreased with rising PCO2Therefore hightemperature and the presence of a conduit to release CO2 willpromote the formation of talcThis experiment has importantgeological and geochemical implications(1)Theresults confirmed themechanism of talcminerali-
zation in Mg-carbonate hosted talc deposits Dolomitereacted with silica-rich hydrothermal fluids to form talccalcite and CO
2 Talc could form at le200∘C whereas pre-
vious hydrothermal experiments examining the CaOndashMgOndashSiO2ndashCO2ndashH2O system were mainly conducted at gt250∘C
However considering the effect of temperature on thereaction rate and other geological conditions massive talcdeposits are still more likely to form at higher temperaturesThe formation of talc along a fault in a Mg-carbonateformation will also weaken the fault thus preventing strongearthquakes(2) Talc in carbonate reservoirs can indicate the activity
of silica-rich hydrothermal fluids Fluid-aided alteration ofdolomite can change the physical properties of dolomitereservoirs substantially The reaction between dolomite andquartz within the carbonate can decrease the total volume ofminerals by 13ndash17 The generation of CO2 can promotethe dissolution of carbonate minerals elsewhere under theappropriate conditions increasing the porosity and perme-ability of carbonate reservoirs However talc minerals mayblock pore throats in the reservoirs Therefore additionalfactors need to be considered when evaluating the effectsof CaMg(CO
3)2ndashSiO2ndashH2O interactions on the physical
properties of carbonate reservoirs(3) The solubility and reactivity of silica should be con-
sidered when using fused silica tubes as reactors in highPndashT experiments The dissolution of silica will increase thecomplexity of the system andweaken themechanical strengthof the tube
Conflicts of Interest
The authors declare that they have no conflicts of interest
Acknowledgments
The dolomite sample was provided by Mr Chunhua ShiMisses Yang Qu Wanlu Gao and Ye Qiu helped the authorsa lot during the micro-XRD analysis and HPOC experiment
10 Geofluids
Outer surfaceInner surface
(a) (b)In
ner s
urfa
ce
(c) (d)
Inner surface
(e) (f)
Figure 8 SEM images of the inner surface of the silica tube (a) Smooth inner surface before the reaction (b) magnification of the squarearea shown in (a) (c) dissolution pits on the inner surface after heating at 200∘C for sim60 days (d) magnification of (c) severe erosion of thesilica on the inner surface of FSCCs containing (e) 10m Na
2SO4and (f) 10m Li
2SO4after heating at 350∘C for 1 h
Dr Rui Wang and Miss Siyu Hu are also thanked for theirhelp in the thermodynamic calculations of the reactionsThis work was financially supported by the National NaturalScience Foundation of China (Grant nos 41230312 and41573054) I-Ming Chou is thankful for the support of theKnowledge Innovation Program (SIDSSE-201302) and theHadal-trench Research Program (XDB06060100) of ChineseAcademy of Sciences
References
[1] L D Meinert ldquoSkarns and skarn depositsrdquo Geoscience Canadavol 19 no 4 pp 145ndash162 1992
[2] L D Meinert G M Dipple and S Nicolescu ldquoWorld skarndepositsrdquo Economic Geology 100th Anniversary Volume pp299ndash336 2005
[3] Y Yao J Chen J Lu R Wang and R Zhang ldquoGeology andgenesis of the Hehuaping magnesian skarn-type cassiterite-sulfide deposit Hunan Province Southern ChinardquoOre GeologyReviews vol 58 no C pp 163ndash184 2014
[4] T M Gordon and H J Greenwood ldquoThe reaction dolomite+ quartz + water = talc + calcite + carbon dioxiderdquo AmericanJournal of Science vol 268 pp 225ndash242 1970
[5] M B Holness ldquoFluid flow paths and mechanisms of fluidinfiltration in carbonates during contact metamorphism TheBeinn an Dubhaich aureole Skyerdquo Journal of MetamorphicGeology vol 15 no 1 pp 59ndash70 1997
Geofluids 11
[6] W Heinrich S S Churakov andM Gottschalk ldquoMineral-fluidequilibria in the system CaOndashMgOndashSiO
2ndashH2OndashCO
2ndashNaCl
and the record of reactive fluid flow in contact metamorphicaureolesrdquo Contributions to Mineralogy and Petrology vol 148no 2 pp 131ndash149 2004
[7] M Wesołowski ldquoThermal decomposition of talc a reviewrdquoThermochimica Acta vol 78 no 1-3 pp 395ndash421 1984
[8] L A Perez-Maqueda A Duran and J L Perez-RodrıguezldquoPreparation of submicron talc particles by sonicationrdquoAppliedClay Science vol 28 no 1-4 pp 245ndash255 2005
[9] R L Johnson ldquoTalcrdquoAmerican Ceramic Society Bulletin vol 71pp 818ndash820 1992
[10] R L Johnson and R L Virta ldquoTalcrdquo American Ceramic SocietyBulletin vol 79 pp 79ndash81 2000
[11] M Z Abzalov ldquoChrome-spinels in gabbro-wehrlite intrusionsof the Pechenga area Kola Peninsula Russia emphasis onalteration featuresrdquo Lithos vol 43 no 3 pp 109ndash134 1998
[12] M F El-Sharkawy ldquoTalc mineralization of ultramafic affinity inthe Eastern Desert of Egyptrdquo Mineralium Deposita vol 35 no4 pp 346ndash363 2000
[13] M Franceschelli G Carcangiu A M Caredda G CrucianiI Memmi and M Zucca ldquoTransformation of cumulate maficrocks to granulite and re-equilibration in amphibolite andgreenschist facies in NE Sardinia Italyrdquo Lithos vol 63 no 1-2pp 1ndash18 2002
[14] S G Tesalina P Nimis T Auge and V V Zaykov ldquoOriginof chromite in mafic-ultramafic-hosted hydrothermal massivesulfides from the Main Uralian Fault South Urals RussiardquoLithos vol 70 no 1-2 pp 39ndash59 2003
[15] D M Evans ldquoMetamorphic modifications of the Muremeramafic-ultramafic intrusions eastern Burundi and their effecton chromite compositionsrdquo Journal of African Earth Sciencesvol 101 pp 19ndash34 2015
[16] T Yamanaka K Maeto H Akashi et al ldquoShallow submarinehydrothermal activity with significant contribution of mag-matic water producing talc chimneys in the Wakamiko CraterofKagoshimaBay southernKyushu Japanrdquo Journal of Volcanol-ogy and Geothermal Research vol 258 pp 74ndash84 2013
[17] B Moine J P Fortune P Moreau and F Viguier ldquoComparativemineralogy geochemistry and conditions of formation of twometasomatic talc and chlorite deposits Trimouns PyreneesFrance and Rabenwald eastern Alps Austriardquo Economic Geol-ogy vol 84 no 5 pp 1398ndash1416 1989
[18] W Prochaska ldquoGeochemistry and genesis of Austrian talcdepositsrdquo Applied Geochemistry vol 4 no 5 pp 511ndash525 1989
[19] P de Parseval S Jiang F Fontan R Wang F Martin and JFreeet ldquoGeology and ore genesis of the Trimouns talc-chloriteore deposit Pyrenees Francerdquo Acta Petrologica Sinica vol 20no 4 pp 877ndash886 2004
[20] A C Gondim and S Jiang ldquoGeologic characteristics and gene-ticmodels for the talc deposits in Parana andBahia BrazilrdquoActaPetrologica Sinica vol 20 no 4 pp 829ndash836 2004
[21] P Boulvais P de Parseval A DrsquoHulst and P Paris ldquoCarbonatealteration associated with talc-chlorite mineralization in theeastern Pyrenees with emphasis on the St Barthelemy MassifrdquoMineralogy and Petrology vol 88 no 3-4 pp 499ndash526 2006
[22] G R Davies and L B Smith Jr ldquoStructurally controlled hydro-thermal dolomite reservoir facies an overviewrdquoAAPG Bulletinvol 90 no 11 pp 1641ndash1690 2006
[23] J Lonnee and H G Machel ldquoPervasive dolomitization withsubsequent hydrothermal alteration in theClarke Lake gas field
Middle Devonian Slave Point Formation British ColumbiaCanadardquo AAPG Bulletin vol 90 no 11 pp 1739ndash1761 2006
[24] J A Luczaj ldquoEvidence against the Dorag (mixing-zone) modelfor dolomitization along theWisconsin arch - A case for hydro-thermal diagenesisrdquo AAPG Bulletin vol 90 no 11 pp 1719ndash1738 2006
[25] L B Smith Jr ldquoOrigin and reservoir characteristics of UpperOrdovician Trenton-Black River hydrothermal dolomite reser-voirs in New YorkrdquoAAPG Bulletin vol 90 no 11 pp 1691ndash17182006
[26] J Parnell ldquoDevonianMagadi-type cherts in theOrcadian BasinScotlandrdquo Journal of Sedimentary Petrology vol 56 no 4 pp495ndash500 1986
[27] J M Garcıa-Ruiz ldquoCarbonate precipitation into alkaline silica-rich environmentsrdquo Geology vol 26 no 9 pp 843ndash846 1998
[28] J Zhang W Hu Y Qian et al ldquoFormation of saddle dolomitesin Upper Cambrian carbonates western Tarim Basin (north-west China) implications for fault-related fluid flowrdquo Marineand Petroleum Geology vol 26 no 8 pp 1428ndash1440 2009
[29] J M McKinley R H Worden and A H Ruffell ldquoContactdiagenesis the effect of an intrusion on reservoir quality in thetriassic sherwood sandstone group Northern Irelandrdquo Journalof Sedimentary Research vol 71 no 3 pp 484ndash495 2001
[30] S Dong D Chen H Qing et al ldquoHydrothermal alteration ofdolostones in the Lower Ordovician Tarim Basin NW Chinamultiple constraints from petrology isotope geochemistry andfluid inclusion microthermometryrdquo Marine and PetroleumGeology vol 46 pp 270ndash286 2013
[31] V Madrucci C W D D Anjos R A Spadini D B Alvesand S M C Anjos ldquoAuthigenic magnesian clays in carbonatereservoirs in Brazilrdquo in Proceedings of the 15th International ClayConference Rio De Janeiro Brazil 2013
[32] C H Scholz ldquoEarthquakes and friction lawsrdquo Nature vol 391no 6662 pp 37ndash42 1998
[33] A M Schleicher B A Van Der Pluijm J G Solum andL N Warr ldquoOrigin and significance of clay-coated fracturesin mudrock fragments of the SAFOD borehole (ParkfieldCalifornia)rdquoGeophysical Research Letters vol 33 no 16 ArticleID L16313 2006
[34] A M Schleicher B A van der Pluijm and L N Warr ldquoNano-coatings of clay and creep of the San Andreas fault at ParkfieldCaliforniardquo Geology vol 38 no 7 pp 667ndash670 2010
[35] C Collettini C Viti S A F Smith and R E HoldsworthldquoDevelopment of interconnected talc networks and weakeningof continental low-angle normal faultsrdquo Geology vol 37 no 6pp 567ndash570 2009
[36] F Tornos and B F Spiro ldquoThe geology and isotope geochem-istry of the talc deposits of Puebla de Lillo (Cantabrian zonenorthern Spain)rdquo Economic Geology vol 95 no 6 pp 1277ndash1296 2000
[37] L Hecht R Freiberger H A Gilg G Grundmann and Y AKostitsyn ldquoRare earth element and isotope (C O Sr) charac-teristics of hydrothermal carbonates genetic implications fordolomite-hosted talc mineralization at Gopfersgrun (Fichtelge-birge Germany)rdquo Chemical Geology vol 155 no 1-2 pp 115ndash130 1999
[38] R Sharma P Joshi and P D Pant ldquoThe role of fluids inthe formation of talc deposits of Rema area Kumaun LesserHimalayardquo Journal of the Geological Society of India vol 73 no2 pp 237ndash248 2009
12 Geofluids
[39] P De Parseval B Moine J P Fortune and J Ferret ldquoFluid-mineral interactions at the origin of the Trimouns talc andchlorite deposit (Pyrenees France)rdquo in Current Research inGeology Applied to Ore Deposits P Fenoll Hach-Ali J Torrez-Ruiz and F Gervilla Eds pp 205ndash209 University of GranadaGranada Granada Spain 1993
[40] M C Boiron P Boulvais M Cathelineau D Banks N Cal-vayrac and G Hubert ldquoFluid circulation at the origin of thetrimouns talc deposit (Pyrenees France)rdquo in Proceedings of the18th Meeting of European Current Research on Fluid InclusionsSiena Italy 2005
[41] P Bayliss andA A Levhinson ldquoLow temperature hydrothermalsynthesis from dolomite or calcite quartz and kaoliniterdquo Claysand Clay Minerals vol 19 no 2 pp 109ndash114 1971
[42] G Skippen ldquoAn experimental model for low pressure meta-morphism of siliceous dolomitic marblerdquo American Journal ofScience vol 274 no 5 pp 487ndash509 1974
[43] J Slaughter D M Kerrick and V J Wall ldquoExperimen-tal and thermodynamic study of equilibria in the systemCaOndashMgOndashSiO
2ndashH2OndashCO
2rdquoAmerican Journal of Science vol
275 pp 143ndash162 1975[44] R G Eggert and D M Kerrick ldquoMetamorphic equilibria in the
siliceous dolomite system 6 kbar experimental data and geo-logic implicationsrdquo Geochimica et Cosmochimica Acta vol 45no 7 pp 1039ndash1049 1981
[45] Z Zhang and Z Duan ldquoPrediction of the PVT properties ofwater over wide range of temperatures and pressures frommolecular dynamics simulationrdquo Physics of the Earth andPlanetary Interiors vol 149 no 3-4 pp 335ndash354 2005
[46] I-M Chou Y Song and R C Burruss ldquoA newmethod for syn-thesizing fluid inclusions in fused silica capillaries containingorganic and inorganic materialrdquo Geochimica et CosmochimicaActa vol 72 no 21 pp 5217ndash5231 2008
[47] I-M Chou R C Burruss and W J Lu ldquoA new optical cellfor spectroscopic studies of geologic fluids at pressures up to100MPardquo in Advances in High-Pressure Technology for Geo-physical Applications J Chen YWang T S Duffy G Shen andL F Dobrzhinetakaya Eds pp 475ndash485 Elsevier AmsterdamNetherlands 2005
[48] K M Rosso and R J Bodnar ldquoMicrothermometric and Ramanspectroscopic detection limits of CO
2in fluid inclusions and the
Raman spectroscopic characterization of CO2rdquo Geochimica et
Cosmochimica Acta vol 59 no 19 pp 3961ndash3975 1995[49] H M Lamadrid Geochemistry of fluid-rock processes [Doctoral
dissertation] Virginia Polytechnic Institute and State Univer-sity Blacksburg VA USA 2016
[50] J H Parker D W Feldman and M Ashkin ldquoRaman scatteringby silicon and germaniumrdquo Physical Review vol 155 no 3 pp712ndash714 1967
[51] Y V Shvarov ldquoAlgorithmization of the numeric equilibriummodeling of dynamic geochemical processesrdquo GeochemistryInternational vol 37 no 6 pp 571ndash576 1999
[52] R B Wright and C H Wang ldquoDensity effect on the Fermiresonance in gaseous CO
2by Raman scatteringrdquoThe Journal of
Chemical Physics vol 58 no 7 pp 2893ndash2895 1973[53] XWang I-M ChouWHu R C Burruss Q Sun and Y Song
ldquoRaman spectroscopic measurements of CO2density experi-
mental calibration with high-pressure optical cell (HPOC) andfused silica capillary capsule (FSCC) with application to fluidinclusion observationsrdquo Geochimica et Cosmochimica Acta vol75 no 14 pp 4080ndash4093 2011
[54] H R Gordon and T K McCubbin Jr ldquoThe 28-micron bandsof CO
2rdquo Journal of Molecular Spectroscopy vol 19 no 1ndash4 pp
137ndash154 1966[55] T Azbej M J Severs B G Rusk and R J Bodnar ldquoIn situ
quantitative analysis of individual H2O-CO
2fluid inclusions by
laser Raman spectroscopyrdquo Chemical Geology vol 237 no 3-4pp 255ndash263 2007
[56] Y Song I M Chou W Hu B Robert and W Lu ldquoCO2
density-raman shift relation derived from synthetic inclusionsin fused silica capillaries and its applicationrdquo Acta GeologicaSinica (English Edition) vol 83 pp 932ndash938 2009
[57] Z Pan I-M Chou and R C Burruss ldquoHydrolysis of polycar-bonate in sub-critical water in fused silica capillary reactor within situ Raman spectroscopyrdquo Green Chemistry vol 11 no 8 pp1105ndash1107 2009
[58] M L Frezzotti F Tecce and A Casagli ldquoRaman spectroscopyfor fluid inclusion analysisrdquo Journal of Geochemical Explorationvol 112 pp 1ndash20 2012
[59] E L Shock and H C Helgeson ldquoCalculation of the thermo-dynamic and transport properties of aqueous species at highpressures and temperatures correlation algorithms for ionicspecies and equation of state predictions to 5 kb and 1000∘CrdquoGeochimica et Cosmochimica Acta vol 52 no 8 pp 2009ndash20361988
[60] O S Pokrovsky SVGolubev J Schott andACastillo ldquoCalcitedolomite and magnesite dissolution kinetics in aqueous solu-tions at acid to circumneutral pH 25 to 150∘C and 1 to 55 atmpCO2 New constraints on CO
2sequestration in sedimentary
basinsrdquo Chemical Geology vol 265 no 1-2 pp 20ndash32 2009[61] YGarrabos R Tufeu B LeNeindre G Zalczer andD Beysens
ldquoRayleigh andRaman scattering near the critical point of carbondioxiderdquo The Journal of Chemical Physics vol 72 no 8 pp4637ndash4651 1979
[62] J H Nicola J F Scott R M Couto andMM Correa ldquoRamanspectra of dolomite [CaMg(CO
3)2]rdquo Physical Review B vol 14
no 10 pp 4676ndash4678 1976[63] S Gunasekaran G Anbalagan and S Pandi ldquoRaman and
infrared spectra of carbonates of calcite structurerdquo Journal ofRaman Spectroscopy vol 37 no 9 pp 892ndash899 2006
[64] G J Rosasco and J J Blaha ldquoRaman microprobe spectra andvibrationalmode assignments of talcrdquoApplied Spectroscopy vol34 no 2 pp 140ndash144 1980
[65] V Trommsdorff and B W Evans ldquoAntigorite-ophicarbo-nates phase relations in a portion of the system CaOndashMgOndashSiO2ndashH2OndashCO
2rdquo Contributions to Mineralogy and Petrology
vol 60 no 1 pp 39ndash56 1977[66] V Trommsdorff and J A D Connolly ldquoConstraints on phase
diagram topology for the systemCaOndashMgOndashSiO2ndashCO2ndashH2Ordquo
Contributions to Mineralogy and Petrology vol 104 no 1 pp 1ndash7 1990
[67] B S Van Gosen H A Lowers S J Sutley and C A GentldquoUsing the geologic setting of talc deposits as an indicator ofamphibole asbestos contentrdquo Environmental Geology vol 45no 7 pp 920ndash939 2004
[68] W Johannes ldquoAn experimental investigation of the systemMgO-SiO
2-H2O-CO
2rdquo American Journal of Science vol 267
no 9 pp 1083ndash1104 1969[69] E S Schandl and M P Gorton ldquoHydrothermal alteration and
CO2metasomatism (natural carbon sequestration) of komati-
ites in the south-western Abitibi greenstone beltrdquo CanadianMineralogist vol 50 no 1 pp 129ndash146 2012
Geofluids 13
[70] B W Evans and S Guggenheim ldquoTalc phyrophyllite andrelated mineralsrdquo in Reviews in Mineralogy S W Bailey Edvol 19 pp 225ndash294 1988
[71] B Velde ldquoExperimental pseudomorphism of diopside by talcand serpentine in (Ni Mg)Cl
2aqueous solutionsrdquo Geochimica
et Cosmochimica Acta vol 52 no 2 pp 415ndash424 1988[72] A E Williams-Jones C Normand H Clark Vali Jr R F
Martin A Dufresne and Nayebzadeh A ldquoControls of amphi-bole formation in chrysotile from the Jeffrey Mine AsbestosQuebecrdquo inTheHealth Effects Effects of Chrysotile Asbestos R PNolan AM LangerM RossWicks F J andMartin F R Edsvol 5 pp 89ndash104 The Mineralogical Association of CanadaQuebec Quebec Canada 2001
[73] B W Evans ldquoThe serpentinite multisystem revisited chrysotileis metastablerdquo International Geology Review vol 46 no 6 pp479ndash506 2004
[74] I Gunnarsson and S Arnorsson ldquoAmorphous silica solubilityand the thermodynamic properties of H
4SiO∘4in the range of
0∘ to 350∘C at Psatrdquo Geochimica et Cosmochimica Acta vol 64no 13 pp 2295ndash2307 2000
[75] M W Bodine Jr ldquoTrioctahedral clay mineral assemblages inPaleozoic marine evaporite rocksrdquo in Proceedings of the Pre-sented in the Sixth International Symposium on Salt vol 1 pp267ndash284 Toronto Canada 1983
[76] W Schreyer and K Abraham ldquoThree-stage metamorphic his-tory of a whiteschist from Sar e Sang Afghanistan as part ofa former evaporite depositrdquo Contributions to Mineralogy andPetrology vol 59 no 2 pp 111ndash130 1976
[77] T Angerer and S G Hagemann ldquoThe BIF-hosted high-gradeiron ore deposits in the archean koolyanobbing greenstonebelt Western Australia structural control on synorogenic-and weathering-related magnetite- hematite- and goethite-rich iron orerdquo Economic Geology vol 105 no 5 pp 917ndash9452010
[78] P Duuring and S Hagemann ldquoLeaching of silica bands andconcentration of magnetite in Archean BIF by hypogene fluidsBeebyn Fe ore deposit Yilgarn Craton Western AustraliardquoMineralium Deposita vol 48 no 3 pp 341ndash370 2013
[79] D Shin and I Lee ldquoFluid inclusions and their stable isotopegeochemistry of the carbonate-hosted talc deposits near theCretaceous Muamsa Granite South Koreardquo Geochemical Jour-nal vol 40 no 1 pp 69ndash85 2006
[80] P G Novgorodov ldquoSolubility of quartz in anH2OndashCO
2mixture
at 700 degrees C and pressures of 3 and 5 kbarsrdquoGeokhimiya pp1484ndash1489 1975
[81] T M Gerlach ldquoChemical characteristics of the volcanic gasesfrom Nyiragongo lava lake and the generation of CH
4-rich
fluid inclusions in alkaline rocksrdquo Journal of Volcanology ampGeothermal Research vol 8 no 2-4 pp 177ndash189 1980
[82] J V Walther and P M Orville ldquoVolatile production and trans-port in regional metamorphismrdquo Contributions to Mineralogyand Petrology vol 79 no 3 pp 252ndash257 1982
[83] W F Giggenbach ldquoThe origin and evolution of fluids inmagmatic-hydrothermal systemsrdquo in Geochemistry of Hydro-thermalOreDeposits H L Barnes Ed pp 737ndash796WileyNewYork NY USA 3 edition 1997
[84] J B Lowenstern ldquoCarbon dioxide in magmas and implicationsfor hydrothermal systemsrdquoMineralium Deposita vol 36 no 6pp 490ndash502 2001
[85] R Kerrich and W S Fyfe ldquoThe gold-carbonate associationsource of CO
2 and CO
2fixation reactions in Archaean lode
depositsrdquo Chemical Geology vol 33 no 1ndash4 pp 265ndash294 1981
[86] P I Nabelek ldquoCalc-silicate reactions and bedding-controlledisotopic exchange in the Notch Peak aureole Utah implicationsfor differential fluid fluxes with metamorphic graderdquo Journal ofMetamorphic Geology vol 20 no 4 pp 429ndash440 2002
[87] P I Nabelek ldquoFluid evolution and kinetics of metamorphicreactions in calc-silicate contact aureoles - From H
2O to CO
2
and backrdquo Geology vol 35 no 10 pp 927ndash930 2007[88] H G Machel ldquoBacterial and thermochemical sulfate reduction
in diagenetic settings - old and new insightsrdquo SedimentaryGeology vol 140 no 1-2 pp 143ndash175 2001
[89] L Stalker P Farrimond and S R Larter ldquoWater as an oxygensource for the production of oxygenated compounds (includingCO2precursors) during kerogen maturationrdquo Organic Geo-
chemistry vol 22 no 3-5 pp 477ndashIN4 1994[90] Z K Shipton J P Evans D Kirschner P T Kolesar A P
Williams and J Heath ldquoAnalysis of CO2leakage through lsquolow-
permeabilityrsquo faults from natural reservoirs in the ColoradoPlateau east-central Utahrdquo Geological Society Special Publica-tion vol 233 pp 43ndash58 2004
[91] J Byerlee ldquoFriction overpressure and fault normal compres-sionrdquo Geophysical Research Letters vol 17 no 12 pp 2109ndash21121990
[92] C Morrow B Radney and J Byerlee ldquoChapter 3 frictionalstrength and the effective pressure law of montmorillonite andlllite claysrdquo International Geophysics vol 51 no C pp 69ndash881992
[93] C A Morrow D E Moore and D A Lockner ldquoThe effectof mineral bond strength and adsorbed water on fault gougefrictional strengthrdquo Geophysical Research Letters vol 27 no 6pp 815ndash818 2000
[94] D A Lockner C Morrow D Moore and S Hickman ldquoLowstrength of deep San Andreas fault gouge from SAFOD corerdquoNature vol 472 no 7341 pp 82ndash86 2011
[95] D EMoore andM J Rymer ldquoTalc-bearing serpentinite and thecreeping section of the San Andreas faultrdquo Nature vol 448 no7155 pp 795ndash797 2007
[96] DH Zenger ldquoDiscussion lsquoOn the formation and occurrence ofsaddle dolomitersquordquo Journal of Sedimentary Petrology vol 51 no4 pp 1350ndash1352 1981
[97] DAKatzG P Eberli P K Swart andL B Smith Jr ldquoTectonic-hydrothermal brecciation associated with calcite precipitationand permeability destruction in Mississippian carbonate reser-voirs Montana and Wyomingrdquo AAPG Bulletin vol 90 no 11pp 1803ndash1841 2006
[98] M Esteban and C Taberner ldquoSecondary porosity developmentduring late burial in carbonate reservoirs as a result of mixingandor cooling of brinesrdquo Journal of Geochemical Explorationvol 78-79 pp 355ndash359 2003
[99] H G MacHel ldquoInvestigations of burial diagenesis in carbonatehydrocarbon reservoir rocksrdquoGeoscience Canada vol 32 no 3pp 103ndash128 2005
[100] J A Sagan and B S Hart ldquoThree-dimensional seismic-baseddefinition of fault-related porosity development Trenton-BlackRiver interval Saybrook Ohiordquo AAPG Bulletin vol 90 no 11pp 1763ndash1785 2006
[101] F Xing and S Li ldquoGenesis and environment characteristics ofdolomite-hosted quartz and its significance for hydrocarbonexploration in Keping Area Tarim Basin Chinardquo Journal ofEarth Science vol 23 no 4 pp 476ndash489 2012
[102] L Yun and Z Cao ldquoHydrocarbon enrichment pattern andexploration potential of the Ordovician in Shunnan area TarimBasinrdquo Oil and Gas Geology vol 35 no 6 pp 788ndash797 2014
14 Geofluids
[103] Y Li N Ye X Yuan Q Huang B Su and R Zhou ldquoGeologicaland geochemical characteristics of silicified hydrothermal fluidsin Well Shunnan 4 Tarim Basinrdquo Oil and Gas Geology vol 36no 6 pp 934ndash944 2015
[104] L Qi ldquoOil and gas breakthrough in ultra-deep Ordoviciancarbonate formations in Shuntuoguole uplift Tarim BasinrdquoChina Petroleum Exploration vol 21 no 3 pp 38ndash51 2016 (inChinese with English abstract)
[105] H R Qing ldquoAn introduction of petrology and diagenesis ofultra-deep water carbonate reservoirs from the Atlantic Oceanoffshore Brazilrdquo 2017 Oral presentation at Wuxi Institute ofPetroleum Geology of SINOPEC Wuxi China
[106] G J Simandl and S Paradisl ldquoCarbonate-hosted talcrdquo SelectedBritish ColumbiaMineral Deposit Profiles vol 3 pp 35ndash38 1999
[107] Y K Kharaka D R Cole S D Hovorka W D Gunter K GKnauss and BM Freifeld ldquoGas-water-rock interactions in FrioFormation following CO
2injection implications for the storage
of greenhouse gases in sedimentary basinsrdquoGeology vol 34 no7 pp 577ndash580 2006
[108] Z Duan and D Li ldquoCoupled phase and aqueous speciesequilibrium of the H
2OndashCO
2ndashNaClndashCaCO
3system from 0 to
250∘C 1 to 1000 bar with NaCl concentrations up to saturationof haliterdquo Geochimica et Cosmochimica Acta vol 72 no 20 pp5128ndash5145 2008
[109] M R Giles and J DMarshall ldquoConstraints on the developmentof secondary porosity in the subsurface re-evaluation of pro-cessesrdquoMarine and PetroleumGeology vol 3 no 3 pp 243ndash2551986
[110] O S Pokrovsky S V Golubev and J Schott ldquoDissolution kinet-ics of calcite dolomite and magnesite at 25∘C and 0 to 50 atmpCO2rdquo Chemical Geology vol 217 no 3-4 pp 239ndash255 2005
[111] P Cao Z T Karpyn and L Li ldquoThe role of host rock pro-perties in determining potential CO
2migration pathwaysrdquo
International Journal of Greenhouse Gas Control vol 45 pp 18ndash26 2016
[112] M D Fishburn ldquoSignificant results of deep drilling at ElkHills Kern County Californiardquo in Structure Stratigraphy andHydrocarbon Occurrences of the San Joaquin Basin CaliforniaG K Kuespert and S A Reid Eds vol 64 pp 157ndash167 PacificSections Society of Economic Paleontologists and Mineralo-gists and American Association of Petroleum Geologists 1990
[113] E Povoden M Horacek and R Abart ldquoContact metamor-phism of siliceous dolomite and impure limestones from theWerfen formation in the eastern Monzoni contact aureolerdquoMineralogy and Petrology vol 76 no 1-2 pp 99ndash120 2002
[114] S Yuan I-M Chou R C Burruss X Wang and J Li ldquoDispro-portionation and thermochemical sulfate reduction reactions inSndashH2OndashCH
4and SndashD
2OndashCH
4systems from 200 to 340∘C at
elevated pressuresrdquo Geochimica et Cosmochimica Acta vol 118pp 263ndash275 2013
[115] X Wang I-M Chou W Hu and R C Burruss ldquoIn situ obser-vations of liquid-liquid phase separation in aqueous MgSO
4
solutions geological and geochemical implicationsrdquo Geochim-ica et Cosmochimica Acta vol 103 pp 1ndash10 2013
[116] X Wang Y Wan W Hu et al ldquoIn situ observations of liquid-liquid phase separation in aqueous ZnSO
4solutions at tem-
peratures up to 400∘C Implications for Zn2+ndashSO2minus4
[117] X Wang IM Chou W Hu Y Wan and Z Li ldquoPropertiesof lithium under hydrothermal conditions revealed by in situ
Raman spectroscopic characterization of Li2O-SO
3-H2O(D2O)
systems at temperatures up to 420∘Crdquo Chemical Geology vol451 pp 104ndash115 2017
[118] L Shang I-M Chou W Lu R C Burruss and Y ZhangldquoDetermination of diffusion coefficients of hydrogen in fusedsilica between 296 and 523 K by Raman spectroscopy and appli-cation of fused silica capillaries in studying redox reactionsrdquoGeochimica et CosmochimicaActa vol 73 no 18 pp 5435ndash54432009
[119] M Dargent J Dubessy L Truche E F Bazarkina C Nguyen-Trung and P Robert ldquoExperimental study of uranyl(VI) chlo-ride complex formation in acidic LiCl aqueous solutions underhydrothermal conditions (T = 21∘Cndash350∘C Psat) using Ramanspectroscopyrdquo European Journal ofMineralogy vol 25 no 5 pp765ndash775 2013
[120] YWanXWangWHu and I-MChou ldquoRaman spectroscopicobservations of the ion association between Mg2+ and SO2minus
4
in MgSO4-saturated droplets at temperatures of le380∘Crdquo The
Journal of Physical Chemistry A vol 119 no 34 pp 9027ndash90362015
[121] Y Wan X Wang W Hu I M Chou Y Chen and Z Xu ldquoInsitu optical and Raman spectroscopic observations of the effectsof pressure and fluid composition on liquidliquid phase separa-tion in aqueous cadmium sulfate solutions (=400∘C 50MPa)with geological and geochemical implicationsrdquo Geochimica etCosmochimica Acta vol 211 pp 133ndash152 2017
[122] W L Marshall ldquoAmorphous silica solubilitiesmdashI Behavior inaqueous sodium nitrate solutions 25ndash300∘C 0ndash6 molalrdquo Geo-chimica et Cosmochimica Acta vol 44 no 7 pp 907ndash913 1980
[123] C-T A Chen andW LMarshall ldquoAmorphous silica solubilitiesIV Behavior in pure water and aqueous sodium chloridesodium sulfate magnesium chloride and magnesium sulfatesolutions up to 350∘Crdquo Geochimica et Cosmochimica Acta vol46 no 2 pp 279ndash287 1982
[124] B A Fleming and D A Crerar ldquoSilicic acid ionization and cal-culation of silica solubility at elevated temperature and pHapplication to geothermal fluid processing and reinjectionrdquoGeothermics vol 11 no 1 pp 15ndash29 1982
Table 1 Fermi diad bands splits and peak areas of CO2generated in the FSCC containing dolomite and water at 200∘C and the calculated
degree of reaction
Reaction time (h) Fermi diads and splits (cmminus1) Peak area Degree of reaction ()aV1
V2
Δ V1
V2
V1+ V2
0 mdash mdash mdash 0 0 0 02 128521 138792 10271 31587 36662 68249 1584 128519 138777 10258 53083 77521 130604 3026 128509 13877 10261 55164 81714 136878 3168 128514 138772 10258 59966 955 155466 35910 128484 138749 10265 73141 102321 175462 40620 128551 138804 10253 90065 141902 231967 53622 128545 1388 10255 100018 148336 248354 57428 128537 138795 10258 115519 171856 287375 66440 128543 138798 10255 13279 191084 323874 74843 128566 138821 10255 127099 188707 315806 73046 128576 138823 10247 138806 19958 338386 78249 128563 138817 10254 134642 192119 326761 75560 128539 138794 10255 13706 216374 353434 81765 128562 138816 10254 143307 220862 364169 84270 128559 138814 10255 145465 217231 362696 83887 128501 138757 10256 156179 230784 386963 89492 128549 138793 10244 162326 228882 391208 904104 128573 138811 10238 17136 245737 417097 964137 128567 138804 10237 172976 258905 431881149 128526 138799 10273 174657 250163 42482159 128538 138797 10259 183627 255395 439022171 128531 138793 10262 179781 259946 439727193 128524 138777 10253 169712 268104 437816203 128537 138795 10258 17552 255508 431028213 128566 138821 10255 174085 254889 428974224 12856 138815 10255 1725 25597 42847aThe total Raman peak area of CO2 at equilibrium state is an average of those after reaction for sim120 h Then the degree of reaction can be regarded as 100when the reaction time exceeds 120 h
reaction rates decrease with the increase of experimentaldurationPCO
2 The results also showed that the reaction
rate increased with increasing temperature For example theRaman intensity of CO2 was stronger at higher temperaturewithin a given period of time (Figure 3(a))
32 Solid-Phase Characterization Figure 5 shows XRD pat-terns of the quenched solid relicts in the fused silica tubesAfter heating at 200∘C for sim20 days the talc signals wereweak However heating for 80 days produced calcite andtalc as the main phases in the solid relicts whereas dolomitesignals were hardly visible in the XRD pattern (Figure 5)
The Raman spectrum of the solid phase before heat-ing (Figure 6) showed only dolomite peaks (sim177 30051098 cmminus1 [62]) indicating that the dolostone was of highpurity consistent with the XRD analysis However in addi-tion to dolomite characteristic calcite signals (sim282 and1086 cmminus1 [63]) and talc signals (1905 3605 and 675 cmminus1[64]) appeared after heating at 200∘C for 60 days
Figure 7 shows the morphology of the solid phaseafter heating at 200∘C for 60 days The solid phase has ahoneycomb-like texture and was widely distributed in therelicts (Figures 7(a)ndash7(d)) It was identified by EDS as talc(Figure 7(c)) The talc exhibited unoriented textures becauseit formed under strain-free conditions [21] Some cylindri-cal talc also occurred along the inner surface of the FSCC(Figure 7(d)) The dolomite grains had smooth edges (Fig-ure 7(c)) indicating dissolution during heating Some prod-ucts of rhombohedral calcite (Figure 7(d)) were also presentin the solid phase which formed along with the talc via reac-tion (1)
The amount of Mg-silicate mineral produced at 150∘Cfor 40 days was below the detection limit of the micro-XRD equipment Only dolomite and a small amount ofcalcite were observed in the XRD pattern after heating at150∘C for 40 days (Figure 5) This further supports the viewthat the metamorphic reaction rate is largely dependent ontemperature Some researchers view talc as the initial meta-morphic mineral for the CaMg(CO
3)2ndashSiO2ndashH2O system
6 Geofluids
TotalDegree of reaction
0
1000
2000
3000
4000
5000
Peak
area
0
20
40
60
80
100
Deg
ree o
f rea
ctio
n (
)
40 80 120 160 200 2400Reaction time (h)
sim1285minus1
simminus1
cmcm1385
Figure 4 Raman peak areas of CO2and the degree of reaction
versus reaction time at 200∘CBlack rectangles and red circles denotethe peak areas of the lower band at sim1285 cmminus1 and the upper bandat sim1385 cmminus1 respectively Blue triangles represent the total peakareas of both bandsThe green diamonds represent the degree of thereaction Data plotted are from Table 1
971
55 384
71
302
763
1645
283
81 258
822
4894
227
84
209
05 191
20
171
96
186
99
161
981
6004 1
5216
147
07 143
701
4219
133
691
3102
129
561
2440
123
451
1777
115
181
1437
402
133
6891
266
44
288
26
253
162
3986
219
03
201
262
0639
184
751
7863
156
49 154
19
138
75
110
89
104
471
0602
TalcCalciteDolomite
452
10
10 15 20 25 30 35 4052 (∘)Mo tube
20 days
40 days150∘C
200∘C
80 days200∘C
Figure 5 X-ray patterns of the solid relicts in FSCCs containingdolomite and water after heating at 150∘C for sim40 days (lower blueline) and at 200∘C for sim20 days (middle orange line) and sim80 days(upper black line)
(eg [4ndash6]) However serpentine minerals like lizardite andchrysotile are also likely to form at low temperatures duringmetamorphism of the CaOndashMgOndashSiO
2ndashH2OndashCO
2system
especially in contact or regional metamorphic settings [65ndash67] Some researchers have even pointed out that serpentineforms at lower temperatures than talc during metamorphism
CalciteDolomite
TalcRam
an in
tens
ity (a
u)
Solid phase
400 600 800 1000 1200200Raman shift (cmminus1)
(200∘C 60 days)
Figure 6 Raman spectrum of solid relicts after heating at 200∘C for60 daysThe reference spectra of dolomite calcite and talc were alsoshown for comparison The dolomite spectrum was acquired fromthe sample before heating The calcite spectrum was acquired fromcrystalline calcite and the reference spectrum of talc was cited froman open database hosted by the Department of Geosciences at theUniversity of Arizona (RRUFF Project httprruffinfoindexphp)
Table 2 Variations in the internal pressures of the HPOC contain-ing dolomite and water with experimental duration at 200∘C
serpentine is likely to form in a low-silica environment
Geofluids 7
(a) (b)
MgOSi
Dol
(c)
Talc
CaO
C
(d)
Figure 7 SEM micrographs and EDS analyses of the solid relicts in an FSCC containing dolomite and water after heating at 200∘C for sim60days (a b) Honeycomb-like talc (c) dolomite grains with smooth edges and EDS result of talc (yellow arrow) (d) euhedral calcite formed inthe relicts (white arrow) and cylindrical talc growing on the inner surface of the tube (yellow arrow)
further introduction of SiO2 will make talc stable relativeto serpentine [70ndash73] Considering the fact that talc wascharacterized as the product of Mg-silicate mineral in the200∘C experiment via reaction (1) we speculate that whilenot detected byXRD talc also formed below 200∘C sinceCO
2
was generated during the experiment (see above)
33 Thermodynamic Calculations Due to the limits of theUnithermdatabase we used aqueous silica as the SiO
2species
that participated in the reaction Considering that the solu-bility of amorphous silica was high at elevated temperatures[74] the calculated results should approximate the conditionsof the experiments The Gibbs free energy (Δ119866) of formationfor talc from CaMg(CO3)2 aqueous SiO2 and H
2O at the
pressure and temperature of interest are given in Table 3 TheΔ119866 of reaction decreases with increasing temperature at thesaturation pressure This indicates that the reaction is morefavorable at higher temperatures The Δ119866 becomes negativeat 119879 ge 80∘C which implies that the formation of product talcfrom dolomite and a silica-rich fluid is thermodynamicallyfavored However this reaction may not commence untileven higher temperatures are reached due to the probableinitial kinetic barrier to the reaction These thermodynamiccalculations support the implication from the experimentalresults that talc formation can occur at temperatures above100∘C
4 Discussion
41 Implications for the Formation of Mg-Carbonate-HostedTalc Geologically Prochaska [18] grouped the talc depositsinto five types (1) talc related to ultramafics (eg [13ndash15]) (2)Mg-carbonate-hosted talc (eg [20 37]) (3) metamorphictalc (eg [75 76]) (4) talc related to banded iron forma-tions (mostly minnesotaite [77 78]) and (5) secondary talcdeposits [18] The most economically viable of these depositsare usually related to the metamorphic reaction between anMg-carbonate infiltrated by a silica-rich hydrothermal fluid[18 20 21 37] Intense fractures that increase the permeabilityof geological fluid flow generally develop near such deposits[18 20 21 37 38]
Investigating the formation temperature of talc canimprove our understanding of its mineralization processThis has previously been done using several methods Theseinclude microthermometric measurements of relevant fluidinclusions (eg [39 40 79]) and calculations using talcndashdolo-mite oxygen isotope thermometry assuming that themineralpairs achieve oxygen isotope equilibrium [21 36] In additionthe phase diagram of the CaOndashMgOndashSiO2ndashCO2ndashH2O sys-tem has often been referred to for evaluating the formationtemperature of talc [5 35] The diagram was establishedbased on hydrothermal experiments geological case studiesand thermodynamic calculations [4 5 43 44] However the
8 Geofluids
Table 3 The Gibbs free energies of the reaction 3CaMg(CO3)2+ 4SiO
2(aq) + H
2O = Mg
3(Si4O10)(OH)
2+ 3CaCO
3+ 3CO
2at the
temperatures of interest and their corresponding saturation pressures
Temperature (∘C) Δ119866a (kJmol) 119875satb (bar) Temperature (∘C) ΔG (kJmol) 119875sat (bar)
25 7709 0032 100 ndash7083 101450 4663 0124 110 ndash9951 143460 2771 0199 120 ndash12938 198770 0609 0312 130 ndash16032 270380 ndash1778 0474 140 ndash19223 361590 ndash4351 0702 150 ndash22502 4761aΔ119866 refers to the Gibbs free energy of the reaction b119875sat represents the corresponding saturation pressures which are calculated based on the thermodynamicmodel proposed by Zhang and Duan [45]
experiments used to chart out this systemhave been generallyconducted at gt250∘C [4 41ndash44] The reaction path of thephase diagram at low temperatures was mainly establishedthrough thermodynamic calculations implying the need fortalc forming experiments at temperatures below 250∘C
Some geological case studies attribute low talc mineral-ization temperatures (lt200∘C) derived from adjacent talc anddolomite oxygen isotope thermometry to actually reflect iso-topic disequilibrium [36] This study shows that talc depositscan still form at temperatures below 200∘C on geologicaltime scales especially if the product CO
2can be released
(cf reaction (1)) However large-scale talc mineralization ismore likely to form at higher temperatures (eg 250ndash400∘C)Firstly PCO
2controls the lower thermal limit of talc stability
The onset temperature of the transformation increases withincreasing PCO
2 because CO
2is a product of the metamor-
phic reaction (1) and its presence greatly decreases the solu-bility of SiO
2in the fluid [80] CO
2is a common component
in geological fluids and can be either released from magmas(eg [81ndash84]) or generated from the hydrothermal alterationof carbonate (eg [85ndash87]) The oxidation (eg [88]) andhydrothermal maturation of organic matter are also naturalsources of CO
2[89 90]Therefore talcmineralization should
occur at relatively high temperatures in the presence of CO2
Secondly as our results have shown the reaction rate forreaction (1) increases sharply with increasing temperaturefacilitating talc deposits to form at higher temperatures
This study can also contribute to understanding the faultweakening mechanism in the upper crust The elastic strainaccumulation along a fault can be released through a suddenseismic slip (earthquake) or aseismic creep slip [32] A lowerfrictional coefficient for a fault will facilitate stable creepweakening the fault and suppressing the occurrence of strongearthquakes [35]The frictional coefficient of a fault generallydecreases with increasing temperature [35] Therefore faultsare likely to beweakened due to high temperatures in the deepcrust but not in the cool shallow crust The pervasive distri-bution of clay minerals along faults has also been thought toweaken faults [33ndash35 91ndash94] because layered clay mineralsexhibit much lower frictional coefficients than otherminerals[95] For example talc discovered along the SanAndreas faultzone is responsible for helping in aiding slippage along thefault [35 95] As shown here dolomite could react at le200∘Cwith silica-rich fluids traveling along fault planes to form
talc and hence might be an important mechanism of faultweakening in carbonate sequences in the upper crust
42 Implications for Hydrothermal Dolomite Reservoir Re-search Carbonate rock is the main type of hydrocarbonreservoir worldwide hosting over 60 of petroleum reserves[31] Dolomite hydrocarbon reservoirs are important com-prising about half of the carbonate hydrocarbon reser-voirs worldwide [96] Recent research has suggested thathydrothermal alteration can increase the porosity and per-meability of dolomite reservoirs substantially and is animportant factor affecting the development and distributionof dolomite reservoirs [24 25 97ndash101] The Tarim basin isone of the most important petroliferous basins in China andcontains a lower Palaeozoic carbonate series which is alsoan important hydrocarbon reservoir Recent exploration hasshown that silica-rich hydrothermal fluids have infiltratedthese carbonate series improving the physical properties ofthe reservoirs considerably (eg the Shunnan area of theTarim Basin [102 103]) It has been proposed that silica-richhydrothermal fluids were transported through extensionalfaults from the deep strata to the shallow carbonate sequencewhere they migrated laterally through porous and permeablecarbonate formations (sim6670m in the Shunnan area [104])Hydrothermal fluids originating in deep basins are generallyhot Microthermometric measurements have indicated thatthe silica-rich hydrothermal fluids in the Tarim basin reachover 200∘C [101 103] Given that the lower part of the lowerPalaeozoic sequence is mainly composed of dolomite silica-rich hydrothermal fluids could react with the dolomite toform talc and thus change the physical properties of the reser-voir Recently petrologic and diagenetic research haverevealed pervasive silicification in Early Cretaceous ultra-deep water carbonate reservoirs in the Atlantic Ocean off-shore from Brazil [105] The presence of talc calcite quartzand dolomite on the thin-section scale may indicate that thedolomite was strongly corroded by a silica-rich hydrothermalfluid
Alteration of dolomite to talcwill alsomodify the porosityand permeability of carbonate hydrocarbon reservoirs [29ndash31] The silica required for the mineral alteration can be pro-vided by either silica-rich hydrothermal fluids or silica (egquartz chert and opal) within the carbonate reservoirs [106]If SiO
2derives from quartzchert in the dolomite sequences
Geofluids 9
the hydrothermal alteration would increase the porosity ofthe dolomite reservoirs McKinley et al [29] reported thatthe total volume of minerals within a dolomite reservoir canbe reduced by 13 to 17 through the reaction betweendolomite and quartz in reaction (1) In addition the reactionbetween dolomite and silica-rich hydrothermal fluids can actas an important source of CO
2 in hydrocarbon reservoirsThepresence of CO2 can lower the pH of the formation waterand thus promote the dissolution of carbonate minerals [60107 108] increasing the porosity of the reservoirs [109ndash111]However the pore throats may be blocked by the formationof talc or other clay minerals [29 112] Therefore moredetailed factors should be considered in order to unequi-vocally evaluate the effects of silica-rich hydrothermal fluidsin dolomite reservoirs
Although talc can form from the interaction betweendolomite and silica-rich fluids at low temperatures it isseldom observed in hydrocarbon reservoirs [29 31] for thefollowing two reasons (1)A large amount of CO
2can be pro-
duced by the maturation of organic matter and the reactionbetween carbonate minerals and organic acid [98 101] Thepresence of CO
2decreases the lower thermal stability field
of talc [113] (2)The reaction path is dependent on the com-position of the hydrothermal fluid For example K+ andAl3+ are also important components of geological fluidsMontmorillonite instead of talc is more likely to form inthe presence of only a small quantity of Al3+ [41] and theformation of talc can also be inhibited by K+ [29]
43 Implications for High PndashT Experiment Using Fused SilicaCapillary Tubes as Reactors FSCCs are used to constructsynthetic fluid inclusions containing organic and inorganiccomponents [46] They offer advantages such as being inertto many components especially acids and S allowing forthe convenient synthesis of fluid inclusions and facilitatingin situ optical and Raman spectroscopic observations (eg[57 114ndash117]) Fused silica tubes can tolerate relatively hightemperatures up to 600∘C and pressures up to 300MPa As aresult FSCCs are used in many research fields For examplein addition to construction of synthetic fluid inclusions[46 53 118] FSCCs were used in studying the propertiesof hydrothermal fluids as optical and Raman spectroscopiccells [115ndash117 119ndash121] FSCCs were also used as reactorsin investigating the mechanism of thermochemical sulfatereduction [114] and the decomposition of organic matter[57]
However SiO2 in the FSCC acted as a reagent in thisstudy and was partially dissolved as indicated by the pitson the inner surface of the tube (Figures 8(a)ndash8(d)) Thedissolution of silica from FSCCs containing alkali sulfatesolutions was also observed after quenching from ge350∘C(Figures 8(e) and 8(f)) The severe dissolution of fused silicacan be ascribed to three factors (1) Amorphous silica ismore soluble than quartz especially at high temperaturesIn neutral solutions its solubility increases sharply withtemperature from 100 ppm at 20∘C to 1500 ppm at 310∘C[74 122 123] (2) Under basic conditions the solubility ofamorphous silica is greatly enhanced by the ionization ofsilicic acid (H
4SiO4+ OHminus rarr H
3SiO4
minus + H2O [124]) (3)
SiO2may act as a reagent as it did in this experiment The
presence of dissolution pits will weaken the mechanicalstrength of the silica tube In addition the presence ofdissolved silica can make the system more complicated thanexpected Therefore the solubility and reactivity of silicaunder hydrothermal conditions should be evaluated beforeFSCCs are used as reactors
5 Conclusion
The reactions in the CaMg(CO3)2ndashSiO2ndashH2O system atlow temperatures were investigated using fused silica tubesas reactors Results showed that dolomite reacted with asilica-rich fluid to form talc calcite and CO2 at le200
∘Cand low PCO2 The reaction rate increased with increasingtemperature and decreased with rising PCO2Therefore hightemperature and the presence of a conduit to release CO2 willpromote the formation of talcThis experiment has importantgeological and geochemical implications(1)Theresults confirmed themechanism of talcminerali-
zation in Mg-carbonate hosted talc deposits Dolomitereacted with silica-rich hydrothermal fluids to form talccalcite and CO
2 Talc could form at le200∘C whereas pre-
vious hydrothermal experiments examining the CaOndashMgOndashSiO2ndashCO2ndashH2O system were mainly conducted at gt250∘C
However considering the effect of temperature on thereaction rate and other geological conditions massive talcdeposits are still more likely to form at higher temperaturesThe formation of talc along a fault in a Mg-carbonateformation will also weaken the fault thus preventing strongearthquakes(2) Talc in carbonate reservoirs can indicate the activity
of silica-rich hydrothermal fluids Fluid-aided alteration ofdolomite can change the physical properties of dolomitereservoirs substantially The reaction between dolomite andquartz within the carbonate can decrease the total volume ofminerals by 13ndash17 The generation of CO2 can promotethe dissolution of carbonate minerals elsewhere under theappropriate conditions increasing the porosity and perme-ability of carbonate reservoirs However talc minerals mayblock pore throats in the reservoirs Therefore additionalfactors need to be considered when evaluating the effectsof CaMg(CO
3)2ndashSiO2ndashH2O interactions on the physical
properties of carbonate reservoirs(3) The solubility and reactivity of silica should be con-
sidered when using fused silica tubes as reactors in highPndashT experiments The dissolution of silica will increase thecomplexity of the system andweaken themechanical strengthof the tube
Conflicts of Interest
The authors declare that they have no conflicts of interest
Acknowledgments
The dolomite sample was provided by Mr Chunhua ShiMisses Yang Qu Wanlu Gao and Ye Qiu helped the authorsa lot during the micro-XRD analysis and HPOC experiment
10 Geofluids
Outer surfaceInner surface
(a) (b)In
ner s
urfa
ce
(c) (d)
Inner surface
(e) (f)
Figure 8 SEM images of the inner surface of the silica tube (a) Smooth inner surface before the reaction (b) magnification of the squarearea shown in (a) (c) dissolution pits on the inner surface after heating at 200∘C for sim60 days (d) magnification of (c) severe erosion of thesilica on the inner surface of FSCCs containing (e) 10m Na
2SO4and (f) 10m Li
2SO4after heating at 350∘C for 1 h
Dr Rui Wang and Miss Siyu Hu are also thanked for theirhelp in the thermodynamic calculations of the reactionsThis work was financially supported by the National NaturalScience Foundation of China (Grant nos 41230312 and41573054) I-Ming Chou is thankful for the support of theKnowledge Innovation Program (SIDSSE-201302) and theHadal-trench Research Program (XDB06060100) of ChineseAcademy of Sciences
References
[1] L D Meinert ldquoSkarns and skarn depositsrdquo Geoscience Canadavol 19 no 4 pp 145ndash162 1992
[2] L D Meinert G M Dipple and S Nicolescu ldquoWorld skarndepositsrdquo Economic Geology 100th Anniversary Volume pp299ndash336 2005
[3] Y Yao J Chen J Lu R Wang and R Zhang ldquoGeology andgenesis of the Hehuaping magnesian skarn-type cassiterite-sulfide deposit Hunan Province Southern ChinardquoOre GeologyReviews vol 58 no C pp 163ndash184 2014
[4] T M Gordon and H J Greenwood ldquoThe reaction dolomite+ quartz + water = talc + calcite + carbon dioxiderdquo AmericanJournal of Science vol 268 pp 225ndash242 1970
[5] M B Holness ldquoFluid flow paths and mechanisms of fluidinfiltration in carbonates during contact metamorphism TheBeinn an Dubhaich aureole Skyerdquo Journal of MetamorphicGeology vol 15 no 1 pp 59ndash70 1997
Geofluids 11
[6] W Heinrich S S Churakov andM Gottschalk ldquoMineral-fluidequilibria in the system CaOndashMgOndashSiO
2ndashH2OndashCO
2ndashNaCl
and the record of reactive fluid flow in contact metamorphicaureolesrdquo Contributions to Mineralogy and Petrology vol 148no 2 pp 131ndash149 2004
[7] M Wesołowski ldquoThermal decomposition of talc a reviewrdquoThermochimica Acta vol 78 no 1-3 pp 395ndash421 1984
[8] L A Perez-Maqueda A Duran and J L Perez-RodrıguezldquoPreparation of submicron talc particles by sonicationrdquoAppliedClay Science vol 28 no 1-4 pp 245ndash255 2005
[9] R L Johnson ldquoTalcrdquoAmerican Ceramic Society Bulletin vol 71pp 818ndash820 1992
[10] R L Johnson and R L Virta ldquoTalcrdquo American Ceramic SocietyBulletin vol 79 pp 79ndash81 2000
[11] M Z Abzalov ldquoChrome-spinels in gabbro-wehrlite intrusionsof the Pechenga area Kola Peninsula Russia emphasis onalteration featuresrdquo Lithos vol 43 no 3 pp 109ndash134 1998
[12] M F El-Sharkawy ldquoTalc mineralization of ultramafic affinity inthe Eastern Desert of Egyptrdquo Mineralium Deposita vol 35 no4 pp 346ndash363 2000
[13] M Franceschelli G Carcangiu A M Caredda G CrucianiI Memmi and M Zucca ldquoTransformation of cumulate maficrocks to granulite and re-equilibration in amphibolite andgreenschist facies in NE Sardinia Italyrdquo Lithos vol 63 no 1-2pp 1ndash18 2002
[14] S G Tesalina P Nimis T Auge and V V Zaykov ldquoOriginof chromite in mafic-ultramafic-hosted hydrothermal massivesulfides from the Main Uralian Fault South Urals RussiardquoLithos vol 70 no 1-2 pp 39ndash59 2003
[15] D M Evans ldquoMetamorphic modifications of the Muremeramafic-ultramafic intrusions eastern Burundi and their effecton chromite compositionsrdquo Journal of African Earth Sciencesvol 101 pp 19ndash34 2015
[16] T Yamanaka K Maeto H Akashi et al ldquoShallow submarinehydrothermal activity with significant contribution of mag-matic water producing talc chimneys in the Wakamiko CraterofKagoshimaBay southernKyushu Japanrdquo Journal of Volcanol-ogy and Geothermal Research vol 258 pp 74ndash84 2013
[17] B Moine J P Fortune P Moreau and F Viguier ldquoComparativemineralogy geochemistry and conditions of formation of twometasomatic talc and chlorite deposits Trimouns PyreneesFrance and Rabenwald eastern Alps Austriardquo Economic Geol-ogy vol 84 no 5 pp 1398ndash1416 1989
[18] W Prochaska ldquoGeochemistry and genesis of Austrian talcdepositsrdquo Applied Geochemistry vol 4 no 5 pp 511ndash525 1989
[19] P de Parseval S Jiang F Fontan R Wang F Martin and JFreeet ldquoGeology and ore genesis of the Trimouns talc-chloriteore deposit Pyrenees Francerdquo Acta Petrologica Sinica vol 20no 4 pp 877ndash886 2004
[20] A C Gondim and S Jiang ldquoGeologic characteristics and gene-ticmodels for the talc deposits in Parana andBahia BrazilrdquoActaPetrologica Sinica vol 20 no 4 pp 829ndash836 2004
[21] P Boulvais P de Parseval A DrsquoHulst and P Paris ldquoCarbonatealteration associated with talc-chlorite mineralization in theeastern Pyrenees with emphasis on the St Barthelemy MassifrdquoMineralogy and Petrology vol 88 no 3-4 pp 499ndash526 2006
[22] G R Davies and L B Smith Jr ldquoStructurally controlled hydro-thermal dolomite reservoir facies an overviewrdquoAAPG Bulletinvol 90 no 11 pp 1641ndash1690 2006
[23] J Lonnee and H G Machel ldquoPervasive dolomitization withsubsequent hydrothermal alteration in theClarke Lake gas field
Middle Devonian Slave Point Formation British ColumbiaCanadardquo AAPG Bulletin vol 90 no 11 pp 1739ndash1761 2006
[24] J A Luczaj ldquoEvidence against the Dorag (mixing-zone) modelfor dolomitization along theWisconsin arch - A case for hydro-thermal diagenesisrdquo AAPG Bulletin vol 90 no 11 pp 1719ndash1738 2006
[25] L B Smith Jr ldquoOrigin and reservoir characteristics of UpperOrdovician Trenton-Black River hydrothermal dolomite reser-voirs in New YorkrdquoAAPG Bulletin vol 90 no 11 pp 1691ndash17182006
[26] J Parnell ldquoDevonianMagadi-type cherts in theOrcadian BasinScotlandrdquo Journal of Sedimentary Petrology vol 56 no 4 pp495ndash500 1986
[27] J M Garcıa-Ruiz ldquoCarbonate precipitation into alkaline silica-rich environmentsrdquo Geology vol 26 no 9 pp 843ndash846 1998
[28] J Zhang W Hu Y Qian et al ldquoFormation of saddle dolomitesin Upper Cambrian carbonates western Tarim Basin (north-west China) implications for fault-related fluid flowrdquo Marineand Petroleum Geology vol 26 no 8 pp 1428ndash1440 2009
[29] J M McKinley R H Worden and A H Ruffell ldquoContactdiagenesis the effect of an intrusion on reservoir quality in thetriassic sherwood sandstone group Northern Irelandrdquo Journalof Sedimentary Research vol 71 no 3 pp 484ndash495 2001
[30] S Dong D Chen H Qing et al ldquoHydrothermal alteration ofdolostones in the Lower Ordovician Tarim Basin NW Chinamultiple constraints from petrology isotope geochemistry andfluid inclusion microthermometryrdquo Marine and PetroleumGeology vol 46 pp 270ndash286 2013
[31] V Madrucci C W D D Anjos R A Spadini D B Alvesand S M C Anjos ldquoAuthigenic magnesian clays in carbonatereservoirs in Brazilrdquo in Proceedings of the 15th International ClayConference Rio De Janeiro Brazil 2013
[32] C H Scholz ldquoEarthquakes and friction lawsrdquo Nature vol 391no 6662 pp 37ndash42 1998
[33] A M Schleicher B A Van Der Pluijm J G Solum andL N Warr ldquoOrigin and significance of clay-coated fracturesin mudrock fragments of the SAFOD borehole (ParkfieldCalifornia)rdquoGeophysical Research Letters vol 33 no 16 ArticleID L16313 2006
[34] A M Schleicher B A van der Pluijm and L N Warr ldquoNano-coatings of clay and creep of the San Andreas fault at ParkfieldCaliforniardquo Geology vol 38 no 7 pp 667ndash670 2010
[35] C Collettini C Viti S A F Smith and R E HoldsworthldquoDevelopment of interconnected talc networks and weakeningof continental low-angle normal faultsrdquo Geology vol 37 no 6pp 567ndash570 2009
[36] F Tornos and B F Spiro ldquoThe geology and isotope geochem-istry of the talc deposits of Puebla de Lillo (Cantabrian zonenorthern Spain)rdquo Economic Geology vol 95 no 6 pp 1277ndash1296 2000
[37] L Hecht R Freiberger H A Gilg G Grundmann and Y AKostitsyn ldquoRare earth element and isotope (C O Sr) charac-teristics of hydrothermal carbonates genetic implications fordolomite-hosted talc mineralization at Gopfersgrun (Fichtelge-birge Germany)rdquo Chemical Geology vol 155 no 1-2 pp 115ndash130 1999
[38] R Sharma P Joshi and P D Pant ldquoThe role of fluids inthe formation of talc deposits of Rema area Kumaun LesserHimalayardquo Journal of the Geological Society of India vol 73 no2 pp 237ndash248 2009
12 Geofluids
[39] P De Parseval B Moine J P Fortune and J Ferret ldquoFluid-mineral interactions at the origin of the Trimouns talc andchlorite deposit (Pyrenees France)rdquo in Current Research inGeology Applied to Ore Deposits P Fenoll Hach-Ali J Torrez-Ruiz and F Gervilla Eds pp 205ndash209 University of GranadaGranada Granada Spain 1993
[40] M C Boiron P Boulvais M Cathelineau D Banks N Cal-vayrac and G Hubert ldquoFluid circulation at the origin of thetrimouns talc deposit (Pyrenees France)rdquo in Proceedings of the18th Meeting of European Current Research on Fluid InclusionsSiena Italy 2005
[41] P Bayliss andA A Levhinson ldquoLow temperature hydrothermalsynthesis from dolomite or calcite quartz and kaoliniterdquo Claysand Clay Minerals vol 19 no 2 pp 109ndash114 1971
[42] G Skippen ldquoAn experimental model for low pressure meta-morphism of siliceous dolomitic marblerdquo American Journal ofScience vol 274 no 5 pp 487ndash509 1974
[43] J Slaughter D M Kerrick and V J Wall ldquoExperimen-tal and thermodynamic study of equilibria in the systemCaOndashMgOndashSiO
2ndashH2OndashCO
2rdquoAmerican Journal of Science vol
275 pp 143ndash162 1975[44] R G Eggert and D M Kerrick ldquoMetamorphic equilibria in the
siliceous dolomite system 6 kbar experimental data and geo-logic implicationsrdquo Geochimica et Cosmochimica Acta vol 45no 7 pp 1039ndash1049 1981
[45] Z Zhang and Z Duan ldquoPrediction of the PVT properties ofwater over wide range of temperatures and pressures frommolecular dynamics simulationrdquo Physics of the Earth andPlanetary Interiors vol 149 no 3-4 pp 335ndash354 2005
[46] I-M Chou Y Song and R C Burruss ldquoA newmethod for syn-thesizing fluid inclusions in fused silica capillaries containingorganic and inorganic materialrdquo Geochimica et CosmochimicaActa vol 72 no 21 pp 5217ndash5231 2008
[47] I-M Chou R C Burruss and W J Lu ldquoA new optical cellfor spectroscopic studies of geologic fluids at pressures up to100MPardquo in Advances in High-Pressure Technology for Geo-physical Applications J Chen YWang T S Duffy G Shen andL F Dobrzhinetakaya Eds pp 475ndash485 Elsevier AmsterdamNetherlands 2005
[48] K M Rosso and R J Bodnar ldquoMicrothermometric and Ramanspectroscopic detection limits of CO
2in fluid inclusions and the
Raman spectroscopic characterization of CO2rdquo Geochimica et
Cosmochimica Acta vol 59 no 19 pp 3961ndash3975 1995[49] H M Lamadrid Geochemistry of fluid-rock processes [Doctoral
dissertation] Virginia Polytechnic Institute and State Univer-sity Blacksburg VA USA 2016
[50] J H Parker D W Feldman and M Ashkin ldquoRaman scatteringby silicon and germaniumrdquo Physical Review vol 155 no 3 pp712ndash714 1967
[51] Y V Shvarov ldquoAlgorithmization of the numeric equilibriummodeling of dynamic geochemical processesrdquo GeochemistryInternational vol 37 no 6 pp 571ndash576 1999
[52] R B Wright and C H Wang ldquoDensity effect on the Fermiresonance in gaseous CO
2by Raman scatteringrdquoThe Journal of
Chemical Physics vol 58 no 7 pp 2893ndash2895 1973[53] XWang I-M ChouWHu R C Burruss Q Sun and Y Song
ldquoRaman spectroscopic measurements of CO2density experi-
mental calibration with high-pressure optical cell (HPOC) andfused silica capillary capsule (FSCC) with application to fluidinclusion observationsrdquo Geochimica et Cosmochimica Acta vol75 no 14 pp 4080ndash4093 2011
[54] H R Gordon and T K McCubbin Jr ldquoThe 28-micron bandsof CO
2rdquo Journal of Molecular Spectroscopy vol 19 no 1ndash4 pp
137ndash154 1966[55] T Azbej M J Severs B G Rusk and R J Bodnar ldquoIn situ
quantitative analysis of individual H2O-CO
2fluid inclusions by
laser Raman spectroscopyrdquo Chemical Geology vol 237 no 3-4pp 255ndash263 2007
[56] Y Song I M Chou W Hu B Robert and W Lu ldquoCO2
density-raman shift relation derived from synthetic inclusionsin fused silica capillaries and its applicationrdquo Acta GeologicaSinica (English Edition) vol 83 pp 932ndash938 2009
[57] Z Pan I-M Chou and R C Burruss ldquoHydrolysis of polycar-bonate in sub-critical water in fused silica capillary reactor within situ Raman spectroscopyrdquo Green Chemistry vol 11 no 8 pp1105ndash1107 2009
[58] M L Frezzotti F Tecce and A Casagli ldquoRaman spectroscopyfor fluid inclusion analysisrdquo Journal of Geochemical Explorationvol 112 pp 1ndash20 2012
[59] E L Shock and H C Helgeson ldquoCalculation of the thermo-dynamic and transport properties of aqueous species at highpressures and temperatures correlation algorithms for ionicspecies and equation of state predictions to 5 kb and 1000∘CrdquoGeochimica et Cosmochimica Acta vol 52 no 8 pp 2009ndash20361988
[60] O S Pokrovsky SVGolubev J Schott andACastillo ldquoCalcitedolomite and magnesite dissolution kinetics in aqueous solu-tions at acid to circumneutral pH 25 to 150∘C and 1 to 55 atmpCO2 New constraints on CO
2sequestration in sedimentary
basinsrdquo Chemical Geology vol 265 no 1-2 pp 20ndash32 2009[61] YGarrabos R Tufeu B LeNeindre G Zalczer andD Beysens
ldquoRayleigh andRaman scattering near the critical point of carbondioxiderdquo The Journal of Chemical Physics vol 72 no 8 pp4637ndash4651 1979
[62] J H Nicola J F Scott R M Couto andMM Correa ldquoRamanspectra of dolomite [CaMg(CO
3)2]rdquo Physical Review B vol 14
no 10 pp 4676ndash4678 1976[63] S Gunasekaran G Anbalagan and S Pandi ldquoRaman and
infrared spectra of carbonates of calcite structurerdquo Journal ofRaman Spectroscopy vol 37 no 9 pp 892ndash899 2006
[64] G J Rosasco and J J Blaha ldquoRaman microprobe spectra andvibrationalmode assignments of talcrdquoApplied Spectroscopy vol34 no 2 pp 140ndash144 1980
[65] V Trommsdorff and B W Evans ldquoAntigorite-ophicarbo-nates phase relations in a portion of the system CaOndashMgOndashSiO2ndashH2OndashCO
2rdquo Contributions to Mineralogy and Petrology
vol 60 no 1 pp 39ndash56 1977[66] V Trommsdorff and J A D Connolly ldquoConstraints on phase
diagram topology for the systemCaOndashMgOndashSiO2ndashCO2ndashH2Ordquo
Contributions to Mineralogy and Petrology vol 104 no 1 pp 1ndash7 1990
[67] B S Van Gosen H A Lowers S J Sutley and C A GentldquoUsing the geologic setting of talc deposits as an indicator ofamphibole asbestos contentrdquo Environmental Geology vol 45no 7 pp 920ndash939 2004
[68] W Johannes ldquoAn experimental investigation of the systemMgO-SiO
2-H2O-CO
2rdquo American Journal of Science vol 267
no 9 pp 1083ndash1104 1969[69] E S Schandl and M P Gorton ldquoHydrothermal alteration and
CO2metasomatism (natural carbon sequestration) of komati-
ites in the south-western Abitibi greenstone beltrdquo CanadianMineralogist vol 50 no 1 pp 129ndash146 2012
Geofluids 13
[70] B W Evans and S Guggenheim ldquoTalc phyrophyllite andrelated mineralsrdquo in Reviews in Mineralogy S W Bailey Edvol 19 pp 225ndash294 1988
[71] B Velde ldquoExperimental pseudomorphism of diopside by talcand serpentine in (Ni Mg)Cl
2aqueous solutionsrdquo Geochimica
et Cosmochimica Acta vol 52 no 2 pp 415ndash424 1988[72] A E Williams-Jones C Normand H Clark Vali Jr R F
Martin A Dufresne and Nayebzadeh A ldquoControls of amphi-bole formation in chrysotile from the Jeffrey Mine AsbestosQuebecrdquo inTheHealth Effects Effects of Chrysotile Asbestos R PNolan AM LangerM RossWicks F J andMartin F R Edsvol 5 pp 89ndash104 The Mineralogical Association of CanadaQuebec Quebec Canada 2001
[73] B W Evans ldquoThe serpentinite multisystem revisited chrysotileis metastablerdquo International Geology Review vol 46 no 6 pp479ndash506 2004
[74] I Gunnarsson and S Arnorsson ldquoAmorphous silica solubilityand the thermodynamic properties of H
4SiO∘4in the range of
0∘ to 350∘C at Psatrdquo Geochimica et Cosmochimica Acta vol 64no 13 pp 2295ndash2307 2000
[75] M W Bodine Jr ldquoTrioctahedral clay mineral assemblages inPaleozoic marine evaporite rocksrdquo in Proceedings of the Pre-sented in the Sixth International Symposium on Salt vol 1 pp267ndash284 Toronto Canada 1983
[76] W Schreyer and K Abraham ldquoThree-stage metamorphic his-tory of a whiteschist from Sar e Sang Afghanistan as part ofa former evaporite depositrdquo Contributions to Mineralogy andPetrology vol 59 no 2 pp 111ndash130 1976
[77] T Angerer and S G Hagemann ldquoThe BIF-hosted high-gradeiron ore deposits in the archean koolyanobbing greenstonebelt Western Australia structural control on synorogenic-and weathering-related magnetite- hematite- and goethite-rich iron orerdquo Economic Geology vol 105 no 5 pp 917ndash9452010
[78] P Duuring and S Hagemann ldquoLeaching of silica bands andconcentration of magnetite in Archean BIF by hypogene fluidsBeebyn Fe ore deposit Yilgarn Craton Western AustraliardquoMineralium Deposita vol 48 no 3 pp 341ndash370 2013
[79] D Shin and I Lee ldquoFluid inclusions and their stable isotopegeochemistry of the carbonate-hosted talc deposits near theCretaceous Muamsa Granite South Koreardquo Geochemical Jour-nal vol 40 no 1 pp 69ndash85 2006
[80] P G Novgorodov ldquoSolubility of quartz in anH2OndashCO
2mixture
at 700 degrees C and pressures of 3 and 5 kbarsrdquoGeokhimiya pp1484ndash1489 1975
[81] T M Gerlach ldquoChemical characteristics of the volcanic gasesfrom Nyiragongo lava lake and the generation of CH
4-rich
fluid inclusions in alkaline rocksrdquo Journal of Volcanology ampGeothermal Research vol 8 no 2-4 pp 177ndash189 1980
[82] J V Walther and P M Orville ldquoVolatile production and trans-port in regional metamorphismrdquo Contributions to Mineralogyand Petrology vol 79 no 3 pp 252ndash257 1982
[83] W F Giggenbach ldquoThe origin and evolution of fluids inmagmatic-hydrothermal systemsrdquo in Geochemistry of Hydro-thermalOreDeposits H L Barnes Ed pp 737ndash796WileyNewYork NY USA 3 edition 1997
[84] J B Lowenstern ldquoCarbon dioxide in magmas and implicationsfor hydrothermal systemsrdquoMineralium Deposita vol 36 no 6pp 490ndash502 2001
[85] R Kerrich and W S Fyfe ldquoThe gold-carbonate associationsource of CO
2 and CO
2fixation reactions in Archaean lode
depositsrdquo Chemical Geology vol 33 no 1ndash4 pp 265ndash294 1981
[86] P I Nabelek ldquoCalc-silicate reactions and bedding-controlledisotopic exchange in the Notch Peak aureole Utah implicationsfor differential fluid fluxes with metamorphic graderdquo Journal ofMetamorphic Geology vol 20 no 4 pp 429ndash440 2002
[87] P I Nabelek ldquoFluid evolution and kinetics of metamorphicreactions in calc-silicate contact aureoles - From H
2O to CO
2
and backrdquo Geology vol 35 no 10 pp 927ndash930 2007[88] H G Machel ldquoBacterial and thermochemical sulfate reduction
in diagenetic settings - old and new insightsrdquo SedimentaryGeology vol 140 no 1-2 pp 143ndash175 2001
[89] L Stalker P Farrimond and S R Larter ldquoWater as an oxygensource for the production of oxygenated compounds (includingCO2precursors) during kerogen maturationrdquo Organic Geo-
chemistry vol 22 no 3-5 pp 477ndashIN4 1994[90] Z K Shipton J P Evans D Kirschner P T Kolesar A P
Williams and J Heath ldquoAnalysis of CO2leakage through lsquolow-
permeabilityrsquo faults from natural reservoirs in the ColoradoPlateau east-central Utahrdquo Geological Society Special Publica-tion vol 233 pp 43ndash58 2004
[91] J Byerlee ldquoFriction overpressure and fault normal compres-sionrdquo Geophysical Research Letters vol 17 no 12 pp 2109ndash21121990
[92] C Morrow B Radney and J Byerlee ldquoChapter 3 frictionalstrength and the effective pressure law of montmorillonite andlllite claysrdquo International Geophysics vol 51 no C pp 69ndash881992
[93] C A Morrow D E Moore and D A Lockner ldquoThe effectof mineral bond strength and adsorbed water on fault gougefrictional strengthrdquo Geophysical Research Letters vol 27 no 6pp 815ndash818 2000
[94] D A Lockner C Morrow D Moore and S Hickman ldquoLowstrength of deep San Andreas fault gouge from SAFOD corerdquoNature vol 472 no 7341 pp 82ndash86 2011
[95] D EMoore andM J Rymer ldquoTalc-bearing serpentinite and thecreeping section of the San Andreas faultrdquo Nature vol 448 no7155 pp 795ndash797 2007
[96] DH Zenger ldquoDiscussion lsquoOn the formation and occurrence ofsaddle dolomitersquordquo Journal of Sedimentary Petrology vol 51 no4 pp 1350ndash1352 1981
[97] DAKatzG P Eberli P K Swart andL B Smith Jr ldquoTectonic-hydrothermal brecciation associated with calcite precipitationand permeability destruction in Mississippian carbonate reser-voirs Montana and Wyomingrdquo AAPG Bulletin vol 90 no 11pp 1803ndash1841 2006
[98] M Esteban and C Taberner ldquoSecondary porosity developmentduring late burial in carbonate reservoirs as a result of mixingandor cooling of brinesrdquo Journal of Geochemical Explorationvol 78-79 pp 355ndash359 2003
[99] H G MacHel ldquoInvestigations of burial diagenesis in carbonatehydrocarbon reservoir rocksrdquoGeoscience Canada vol 32 no 3pp 103ndash128 2005
[100] J A Sagan and B S Hart ldquoThree-dimensional seismic-baseddefinition of fault-related porosity development Trenton-BlackRiver interval Saybrook Ohiordquo AAPG Bulletin vol 90 no 11pp 1763ndash1785 2006
[101] F Xing and S Li ldquoGenesis and environment characteristics ofdolomite-hosted quartz and its significance for hydrocarbonexploration in Keping Area Tarim Basin Chinardquo Journal ofEarth Science vol 23 no 4 pp 476ndash489 2012
[102] L Yun and Z Cao ldquoHydrocarbon enrichment pattern andexploration potential of the Ordovician in Shunnan area TarimBasinrdquo Oil and Gas Geology vol 35 no 6 pp 788ndash797 2014
14 Geofluids
[103] Y Li N Ye X Yuan Q Huang B Su and R Zhou ldquoGeologicaland geochemical characteristics of silicified hydrothermal fluidsin Well Shunnan 4 Tarim Basinrdquo Oil and Gas Geology vol 36no 6 pp 934ndash944 2015
[104] L Qi ldquoOil and gas breakthrough in ultra-deep Ordoviciancarbonate formations in Shuntuoguole uplift Tarim BasinrdquoChina Petroleum Exploration vol 21 no 3 pp 38ndash51 2016 (inChinese with English abstract)
[105] H R Qing ldquoAn introduction of petrology and diagenesis ofultra-deep water carbonate reservoirs from the Atlantic Oceanoffshore Brazilrdquo 2017 Oral presentation at Wuxi Institute ofPetroleum Geology of SINOPEC Wuxi China
[106] G J Simandl and S Paradisl ldquoCarbonate-hosted talcrdquo SelectedBritish ColumbiaMineral Deposit Profiles vol 3 pp 35ndash38 1999
[107] Y K Kharaka D R Cole S D Hovorka W D Gunter K GKnauss and BM Freifeld ldquoGas-water-rock interactions in FrioFormation following CO
2injection implications for the storage
of greenhouse gases in sedimentary basinsrdquoGeology vol 34 no7 pp 577ndash580 2006
[108] Z Duan and D Li ldquoCoupled phase and aqueous speciesequilibrium of the H
2OndashCO
2ndashNaClndashCaCO
3system from 0 to
250∘C 1 to 1000 bar with NaCl concentrations up to saturationof haliterdquo Geochimica et Cosmochimica Acta vol 72 no 20 pp5128ndash5145 2008
[109] M R Giles and J DMarshall ldquoConstraints on the developmentof secondary porosity in the subsurface re-evaluation of pro-cessesrdquoMarine and PetroleumGeology vol 3 no 3 pp 243ndash2551986
[110] O S Pokrovsky S V Golubev and J Schott ldquoDissolution kinet-ics of calcite dolomite and magnesite at 25∘C and 0 to 50 atmpCO2rdquo Chemical Geology vol 217 no 3-4 pp 239ndash255 2005
[111] P Cao Z T Karpyn and L Li ldquoThe role of host rock pro-perties in determining potential CO
2migration pathwaysrdquo
International Journal of Greenhouse Gas Control vol 45 pp 18ndash26 2016
[112] M D Fishburn ldquoSignificant results of deep drilling at ElkHills Kern County Californiardquo in Structure Stratigraphy andHydrocarbon Occurrences of the San Joaquin Basin CaliforniaG K Kuespert and S A Reid Eds vol 64 pp 157ndash167 PacificSections Society of Economic Paleontologists and Mineralo-gists and American Association of Petroleum Geologists 1990
[113] E Povoden M Horacek and R Abart ldquoContact metamor-phism of siliceous dolomite and impure limestones from theWerfen formation in the eastern Monzoni contact aureolerdquoMineralogy and Petrology vol 76 no 1-2 pp 99ndash120 2002
[114] S Yuan I-M Chou R C Burruss X Wang and J Li ldquoDispro-portionation and thermochemical sulfate reduction reactions inSndashH2OndashCH
4and SndashD
2OndashCH
4systems from 200 to 340∘C at
elevated pressuresrdquo Geochimica et Cosmochimica Acta vol 118pp 263ndash275 2013
[115] X Wang I-M Chou W Hu and R C Burruss ldquoIn situ obser-vations of liquid-liquid phase separation in aqueous MgSO
4
solutions geological and geochemical implicationsrdquo Geochim-ica et Cosmochimica Acta vol 103 pp 1ndash10 2013
[116] X Wang Y Wan W Hu et al ldquoIn situ observations of liquid-liquid phase separation in aqueous ZnSO
4solutions at tem-
peratures up to 400∘C Implications for Zn2+ndashSO2minus4
[117] X Wang IM Chou W Hu Y Wan and Z Li ldquoPropertiesof lithium under hydrothermal conditions revealed by in situ
Raman spectroscopic characterization of Li2O-SO
3-H2O(D2O)
systems at temperatures up to 420∘Crdquo Chemical Geology vol451 pp 104ndash115 2017
[118] L Shang I-M Chou W Lu R C Burruss and Y ZhangldquoDetermination of diffusion coefficients of hydrogen in fusedsilica between 296 and 523 K by Raman spectroscopy and appli-cation of fused silica capillaries in studying redox reactionsrdquoGeochimica et CosmochimicaActa vol 73 no 18 pp 5435ndash54432009
[119] M Dargent J Dubessy L Truche E F Bazarkina C Nguyen-Trung and P Robert ldquoExperimental study of uranyl(VI) chlo-ride complex formation in acidic LiCl aqueous solutions underhydrothermal conditions (T = 21∘Cndash350∘C Psat) using Ramanspectroscopyrdquo European Journal ofMineralogy vol 25 no 5 pp765ndash775 2013
[120] YWanXWangWHu and I-MChou ldquoRaman spectroscopicobservations of the ion association between Mg2+ and SO2minus
4
in MgSO4-saturated droplets at temperatures of le380∘Crdquo The
Journal of Physical Chemistry A vol 119 no 34 pp 9027ndash90362015
[121] Y Wan X Wang W Hu I M Chou Y Chen and Z Xu ldquoInsitu optical and Raman spectroscopic observations of the effectsof pressure and fluid composition on liquidliquid phase separa-tion in aqueous cadmium sulfate solutions (=400∘C 50MPa)with geological and geochemical implicationsrdquo Geochimica etCosmochimica Acta vol 211 pp 133ndash152 2017
[122] W L Marshall ldquoAmorphous silica solubilitiesmdashI Behavior inaqueous sodium nitrate solutions 25ndash300∘C 0ndash6 molalrdquo Geo-chimica et Cosmochimica Acta vol 44 no 7 pp 907ndash913 1980
[123] C-T A Chen andW LMarshall ldquoAmorphous silica solubilitiesIV Behavior in pure water and aqueous sodium chloridesodium sulfate magnesium chloride and magnesium sulfatesolutions up to 350∘Crdquo Geochimica et Cosmochimica Acta vol46 no 2 pp 279ndash287 1982
[124] B A Fleming and D A Crerar ldquoSilicic acid ionization and cal-culation of silica solubility at elevated temperature and pHapplication to geothermal fluid processing and reinjectionrdquoGeothermics vol 11 no 1 pp 15ndash29 1982
Figure 4 Raman peak areas of CO2and the degree of reaction
versus reaction time at 200∘CBlack rectangles and red circles denotethe peak areas of the lower band at sim1285 cmminus1 and the upper bandat sim1385 cmminus1 respectively Blue triangles represent the total peakareas of both bandsThe green diamonds represent the degree of thereaction Data plotted are from Table 1
971
55 384
71
302
763
1645
283
81 258
822
4894
227
84
209
05 191
20
171
96
186
99
161
981
6004 1
5216
147
07 143
701
4219
133
691
3102
129
561
2440
123
451
1777
115
181
1437
402
133
6891
266
44
288
26
253
162
3986
219
03
201
262
0639
184
751
7863
156
49 154
19
138
75
110
89
104
471
0602
TalcCalciteDolomite
452
10
10 15 20 25 30 35 4052 (∘)Mo tube
20 days
40 days150∘C
200∘C
80 days200∘C
Figure 5 X-ray patterns of the solid relicts in FSCCs containingdolomite and water after heating at 150∘C for sim40 days (lower blueline) and at 200∘C for sim20 days (middle orange line) and sim80 days(upper black line)
(eg [4ndash6]) However serpentine minerals like lizardite andchrysotile are also likely to form at low temperatures duringmetamorphism of the CaOndashMgOndashSiO
2ndashH2OndashCO
2system
especially in contact or regional metamorphic settings [65ndash67] Some researchers have even pointed out that serpentineforms at lower temperatures than talc during metamorphism
CalciteDolomite
TalcRam
an in
tens
ity (a
u)
Solid phase
400 600 800 1000 1200200Raman shift (cmminus1)
(200∘C 60 days)
Figure 6 Raman spectrum of solid relicts after heating at 200∘C for60 daysThe reference spectra of dolomite calcite and talc were alsoshown for comparison The dolomite spectrum was acquired fromthe sample before heating The calcite spectrum was acquired fromcrystalline calcite and the reference spectrum of talc was cited froman open database hosted by the Department of Geosciences at theUniversity of Arizona (RRUFF Project httprruffinfoindexphp)
Table 2 Variations in the internal pressures of the HPOC contain-ing dolomite and water with experimental duration at 200∘C
serpentine is likely to form in a low-silica environment
Geofluids 7
(a) (b)
MgOSi
Dol
(c)
Talc
CaO
C
(d)
Figure 7 SEM micrographs and EDS analyses of the solid relicts in an FSCC containing dolomite and water after heating at 200∘C for sim60days (a b) Honeycomb-like talc (c) dolomite grains with smooth edges and EDS result of talc (yellow arrow) (d) euhedral calcite formed inthe relicts (white arrow) and cylindrical talc growing on the inner surface of the tube (yellow arrow)
further introduction of SiO2 will make talc stable relativeto serpentine [70ndash73] Considering the fact that talc wascharacterized as the product of Mg-silicate mineral in the200∘C experiment via reaction (1) we speculate that whilenot detected byXRD talc also formed below 200∘C sinceCO
2
was generated during the experiment (see above)
33 Thermodynamic Calculations Due to the limits of theUnithermdatabase we used aqueous silica as the SiO
2species
that participated in the reaction Considering that the solu-bility of amorphous silica was high at elevated temperatures[74] the calculated results should approximate the conditionsof the experiments The Gibbs free energy (Δ119866) of formationfor talc from CaMg(CO3)2 aqueous SiO2 and H
2O at the
pressure and temperature of interest are given in Table 3 TheΔ119866 of reaction decreases with increasing temperature at thesaturation pressure This indicates that the reaction is morefavorable at higher temperatures The Δ119866 becomes negativeat 119879 ge 80∘C which implies that the formation of product talcfrom dolomite and a silica-rich fluid is thermodynamicallyfavored However this reaction may not commence untileven higher temperatures are reached due to the probableinitial kinetic barrier to the reaction These thermodynamiccalculations support the implication from the experimentalresults that talc formation can occur at temperatures above100∘C
4 Discussion
41 Implications for the Formation of Mg-Carbonate-HostedTalc Geologically Prochaska [18] grouped the talc depositsinto five types (1) talc related to ultramafics (eg [13ndash15]) (2)Mg-carbonate-hosted talc (eg [20 37]) (3) metamorphictalc (eg [75 76]) (4) talc related to banded iron forma-tions (mostly minnesotaite [77 78]) and (5) secondary talcdeposits [18] The most economically viable of these depositsare usually related to the metamorphic reaction between anMg-carbonate infiltrated by a silica-rich hydrothermal fluid[18 20 21 37] Intense fractures that increase the permeabilityof geological fluid flow generally develop near such deposits[18 20 21 37 38]
Investigating the formation temperature of talc canimprove our understanding of its mineralization processThis has previously been done using several methods Theseinclude microthermometric measurements of relevant fluidinclusions (eg [39 40 79]) and calculations using talcndashdolo-mite oxygen isotope thermometry assuming that themineralpairs achieve oxygen isotope equilibrium [21 36] In additionthe phase diagram of the CaOndashMgOndashSiO2ndashCO2ndashH2O sys-tem has often been referred to for evaluating the formationtemperature of talc [5 35] The diagram was establishedbased on hydrothermal experiments geological case studiesand thermodynamic calculations [4 5 43 44] However the
8 Geofluids
Table 3 The Gibbs free energies of the reaction 3CaMg(CO3)2+ 4SiO
2(aq) + H
2O = Mg
3(Si4O10)(OH)
2+ 3CaCO
3+ 3CO
2at the
temperatures of interest and their corresponding saturation pressures
Temperature (∘C) Δ119866a (kJmol) 119875satb (bar) Temperature (∘C) ΔG (kJmol) 119875sat (bar)
25 7709 0032 100 ndash7083 101450 4663 0124 110 ndash9951 143460 2771 0199 120 ndash12938 198770 0609 0312 130 ndash16032 270380 ndash1778 0474 140 ndash19223 361590 ndash4351 0702 150 ndash22502 4761aΔ119866 refers to the Gibbs free energy of the reaction b119875sat represents the corresponding saturation pressures which are calculated based on the thermodynamicmodel proposed by Zhang and Duan [45]
experiments used to chart out this systemhave been generallyconducted at gt250∘C [4 41ndash44] The reaction path of thephase diagram at low temperatures was mainly establishedthrough thermodynamic calculations implying the need fortalc forming experiments at temperatures below 250∘C
Some geological case studies attribute low talc mineral-ization temperatures (lt200∘C) derived from adjacent talc anddolomite oxygen isotope thermometry to actually reflect iso-topic disequilibrium [36] This study shows that talc depositscan still form at temperatures below 200∘C on geologicaltime scales especially if the product CO
2can be released
(cf reaction (1)) However large-scale talc mineralization ismore likely to form at higher temperatures (eg 250ndash400∘C)Firstly PCO
2controls the lower thermal limit of talc stability
The onset temperature of the transformation increases withincreasing PCO
2 because CO
2is a product of the metamor-
phic reaction (1) and its presence greatly decreases the solu-bility of SiO
2in the fluid [80] CO
2is a common component
in geological fluids and can be either released from magmas(eg [81ndash84]) or generated from the hydrothermal alterationof carbonate (eg [85ndash87]) The oxidation (eg [88]) andhydrothermal maturation of organic matter are also naturalsources of CO
2[89 90]Therefore talcmineralization should
occur at relatively high temperatures in the presence of CO2
Secondly as our results have shown the reaction rate forreaction (1) increases sharply with increasing temperaturefacilitating talc deposits to form at higher temperatures
This study can also contribute to understanding the faultweakening mechanism in the upper crust The elastic strainaccumulation along a fault can be released through a suddenseismic slip (earthquake) or aseismic creep slip [32] A lowerfrictional coefficient for a fault will facilitate stable creepweakening the fault and suppressing the occurrence of strongearthquakes [35]The frictional coefficient of a fault generallydecreases with increasing temperature [35] Therefore faultsare likely to beweakened due to high temperatures in the deepcrust but not in the cool shallow crust The pervasive distri-bution of clay minerals along faults has also been thought toweaken faults [33ndash35 91ndash94] because layered clay mineralsexhibit much lower frictional coefficients than otherminerals[95] For example talc discovered along the SanAndreas faultzone is responsible for helping in aiding slippage along thefault [35 95] As shown here dolomite could react at le200∘Cwith silica-rich fluids traveling along fault planes to form
talc and hence might be an important mechanism of faultweakening in carbonate sequences in the upper crust
42 Implications for Hydrothermal Dolomite Reservoir Re-search Carbonate rock is the main type of hydrocarbonreservoir worldwide hosting over 60 of petroleum reserves[31] Dolomite hydrocarbon reservoirs are important com-prising about half of the carbonate hydrocarbon reser-voirs worldwide [96] Recent research has suggested thathydrothermal alteration can increase the porosity and per-meability of dolomite reservoirs substantially and is animportant factor affecting the development and distributionof dolomite reservoirs [24 25 97ndash101] The Tarim basin isone of the most important petroliferous basins in China andcontains a lower Palaeozoic carbonate series which is alsoan important hydrocarbon reservoir Recent exploration hasshown that silica-rich hydrothermal fluids have infiltratedthese carbonate series improving the physical properties ofthe reservoirs considerably (eg the Shunnan area of theTarim Basin [102 103]) It has been proposed that silica-richhydrothermal fluids were transported through extensionalfaults from the deep strata to the shallow carbonate sequencewhere they migrated laterally through porous and permeablecarbonate formations (sim6670m in the Shunnan area [104])Hydrothermal fluids originating in deep basins are generallyhot Microthermometric measurements have indicated thatthe silica-rich hydrothermal fluids in the Tarim basin reachover 200∘C [101 103] Given that the lower part of the lowerPalaeozoic sequence is mainly composed of dolomite silica-rich hydrothermal fluids could react with the dolomite toform talc and thus change the physical properties of the reser-voir Recently petrologic and diagenetic research haverevealed pervasive silicification in Early Cretaceous ultra-deep water carbonate reservoirs in the Atlantic Ocean off-shore from Brazil [105] The presence of talc calcite quartzand dolomite on the thin-section scale may indicate that thedolomite was strongly corroded by a silica-rich hydrothermalfluid
Alteration of dolomite to talcwill alsomodify the porosityand permeability of carbonate hydrocarbon reservoirs [29ndash31] The silica required for the mineral alteration can be pro-vided by either silica-rich hydrothermal fluids or silica (egquartz chert and opal) within the carbonate reservoirs [106]If SiO
2derives from quartzchert in the dolomite sequences
Geofluids 9
the hydrothermal alteration would increase the porosity ofthe dolomite reservoirs McKinley et al [29] reported thatthe total volume of minerals within a dolomite reservoir canbe reduced by 13 to 17 through the reaction betweendolomite and quartz in reaction (1) In addition the reactionbetween dolomite and silica-rich hydrothermal fluids can actas an important source of CO
2 in hydrocarbon reservoirsThepresence of CO2 can lower the pH of the formation waterand thus promote the dissolution of carbonate minerals [60107 108] increasing the porosity of the reservoirs [109ndash111]However the pore throats may be blocked by the formationof talc or other clay minerals [29 112] Therefore moredetailed factors should be considered in order to unequi-vocally evaluate the effects of silica-rich hydrothermal fluidsin dolomite reservoirs
Although talc can form from the interaction betweendolomite and silica-rich fluids at low temperatures it isseldom observed in hydrocarbon reservoirs [29 31] for thefollowing two reasons (1)A large amount of CO
2can be pro-
duced by the maturation of organic matter and the reactionbetween carbonate minerals and organic acid [98 101] Thepresence of CO
2decreases the lower thermal stability field
of talc [113] (2)The reaction path is dependent on the com-position of the hydrothermal fluid For example K+ andAl3+ are also important components of geological fluidsMontmorillonite instead of talc is more likely to form inthe presence of only a small quantity of Al3+ [41] and theformation of talc can also be inhibited by K+ [29]
43 Implications for High PndashT Experiment Using Fused SilicaCapillary Tubes as Reactors FSCCs are used to constructsynthetic fluid inclusions containing organic and inorganiccomponents [46] They offer advantages such as being inertto many components especially acids and S allowing forthe convenient synthesis of fluid inclusions and facilitatingin situ optical and Raman spectroscopic observations (eg[57 114ndash117]) Fused silica tubes can tolerate relatively hightemperatures up to 600∘C and pressures up to 300MPa As aresult FSCCs are used in many research fields For examplein addition to construction of synthetic fluid inclusions[46 53 118] FSCCs were used in studying the propertiesof hydrothermal fluids as optical and Raman spectroscopiccells [115ndash117 119ndash121] FSCCs were also used as reactorsin investigating the mechanism of thermochemical sulfatereduction [114] and the decomposition of organic matter[57]
However SiO2 in the FSCC acted as a reagent in thisstudy and was partially dissolved as indicated by the pitson the inner surface of the tube (Figures 8(a)ndash8(d)) Thedissolution of silica from FSCCs containing alkali sulfatesolutions was also observed after quenching from ge350∘C(Figures 8(e) and 8(f)) The severe dissolution of fused silicacan be ascribed to three factors (1) Amorphous silica ismore soluble than quartz especially at high temperaturesIn neutral solutions its solubility increases sharply withtemperature from 100 ppm at 20∘C to 1500 ppm at 310∘C[74 122 123] (2) Under basic conditions the solubility ofamorphous silica is greatly enhanced by the ionization ofsilicic acid (H
4SiO4+ OHminus rarr H
3SiO4
minus + H2O [124]) (3)
SiO2may act as a reagent as it did in this experiment The
presence of dissolution pits will weaken the mechanicalstrength of the silica tube In addition the presence ofdissolved silica can make the system more complicated thanexpected Therefore the solubility and reactivity of silicaunder hydrothermal conditions should be evaluated beforeFSCCs are used as reactors
5 Conclusion
The reactions in the CaMg(CO3)2ndashSiO2ndashH2O system atlow temperatures were investigated using fused silica tubesas reactors Results showed that dolomite reacted with asilica-rich fluid to form talc calcite and CO2 at le200
∘Cand low PCO2 The reaction rate increased with increasingtemperature and decreased with rising PCO2Therefore hightemperature and the presence of a conduit to release CO2 willpromote the formation of talcThis experiment has importantgeological and geochemical implications(1)Theresults confirmed themechanism of talcminerali-
zation in Mg-carbonate hosted talc deposits Dolomitereacted with silica-rich hydrothermal fluids to form talccalcite and CO
2 Talc could form at le200∘C whereas pre-
vious hydrothermal experiments examining the CaOndashMgOndashSiO2ndashCO2ndashH2O system were mainly conducted at gt250∘C
However considering the effect of temperature on thereaction rate and other geological conditions massive talcdeposits are still more likely to form at higher temperaturesThe formation of talc along a fault in a Mg-carbonateformation will also weaken the fault thus preventing strongearthquakes(2) Talc in carbonate reservoirs can indicate the activity
of silica-rich hydrothermal fluids Fluid-aided alteration ofdolomite can change the physical properties of dolomitereservoirs substantially The reaction between dolomite andquartz within the carbonate can decrease the total volume ofminerals by 13ndash17 The generation of CO2 can promotethe dissolution of carbonate minerals elsewhere under theappropriate conditions increasing the porosity and perme-ability of carbonate reservoirs However talc minerals mayblock pore throats in the reservoirs Therefore additionalfactors need to be considered when evaluating the effectsof CaMg(CO
3)2ndashSiO2ndashH2O interactions on the physical
properties of carbonate reservoirs(3) The solubility and reactivity of silica should be con-
sidered when using fused silica tubes as reactors in highPndashT experiments The dissolution of silica will increase thecomplexity of the system andweaken themechanical strengthof the tube
Conflicts of Interest
The authors declare that they have no conflicts of interest
Acknowledgments
The dolomite sample was provided by Mr Chunhua ShiMisses Yang Qu Wanlu Gao and Ye Qiu helped the authorsa lot during the micro-XRD analysis and HPOC experiment
10 Geofluids
Outer surfaceInner surface
(a) (b)In
ner s
urfa
ce
(c) (d)
Inner surface
(e) (f)
Figure 8 SEM images of the inner surface of the silica tube (a) Smooth inner surface before the reaction (b) magnification of the squarearea shown in (a) (c) dissolution pits on the inner surface after heating at 200∘C for sim60 days (d) magnification of (c) severe erosion of thesilica on the inner surface of FSCCs containing (e) 10m Na
2SO4and (f) 10m Li
2SO4after heating at 350∘C for 1 h
Dr Rui Wang and Miss Siyu Hu are also thanked for theirhelp in the thermodynamic calculations of the reactionsThis work was financially supported by the National NaturalScience Foundation of China (Grant nos 41230312 and41573054) I-Ming Chou is thankful for the support of theKnowledge Innovation Program (SIDSSE-201302) and theHadal-trench Research Program (XDB06060100) of ChineseAcademy of Sciences
References
[1] L D Meinert ldquoSkarns and skarn depositsrdquo Geoscience Canadavol 19 no 4 pp 145ndash162 1992
[2] L D Meinert G M Dipple and S Nicolescu ldquoWorld skarndepositsrdquo Economic Geology 100th Anniversary Volume pp299ndash336 2005
[3] Y Yao J Chen J Lu R Wang and R Zhang ldquoGeology andgenesis of the Hehuaping magnesian skarn-type cassiterite-sulfide deposit Hunan Province Southern ChinardquoOre GeologyReviews vol 58 no C pp 163ndash184 2014
[4] T M Gordon and H J Greenwood ldquoThe reaction dolomite+ quartz + water = talc + calcite + carbon dioxiderdquo AmericanJournal of Science vol 268 pp 225ndash242 1970
[5] M B Holness ldquoFluid flow paths and mechanisms of fluidinfiltration in carbonates during contact metamorphism TheBeinn an Dubhaich aureole Skyerdquo Journal of MetamorphicGeology vol 15 no 1 pp 59ndash70 1997
Geofluids 11
[6] W Heinrich S S Churakov andM Gottschalk ldquoMineral-fluidequilibria in the system CaOndashMgOndashSiO
2ndashH2OndashCO
2ndashNaCl
and the record of reactive fluid flow in contact metamorphicaureolesrdquo Contributions to Mineralogy and Petrology vol 148no 2 pp 131ndash149 2004
[7] M Wesołowski ldquoThermal decomposition of talc a reviewrdquoThermochimica Acta vol 78 no 1-3 pp 395ndash421 1984
[8] L A Perez-Maqueda A Duran and J L Perez-RodrıguezldquoPreparation of submicron talc particles by sonicationrdquoAppliedClay Science vol 28 no 1-4 pp 245ndash255 2005
[9] R L Johnson ldquoTalcrdquoAmerican Ceramic Society Bulletin vol 71pp 818ndash820 1992
[10] R L Johnson and R L Virta ldquoTalcrdquo American Ceramic SocietyBulletin vol 79 pp 79ndash81 2000
[11] M Z Abzalov ldquoChrome-spinels in gabbro-wehrlite intrusionsof the Pechenga area Kola Peninsula Russia emphasis onalteration featuresrdquo Lithos vol 43 no 3 pp 109ndash134 1998
[12] M F El-Sharkawy ldquoTalc mineralization of ultramafic affinity inthe Eastern Desert of Egyptrdquo Mineralium Deposita vol 35 no4 pp 346ndash363 2000
[13] M Franceschelli G Carcangiu A M Caredda G CrucianiI Memmi and M Zucca ldquoTransformation of cumulate maficrocks to granulite and re-equilibration in amphibolite andgreenschist facies in NE Sardinia Italyrdquo Lithos vol 63 no 1-2pp 1ndash18 2002
[14] S G Tesalina P Nimis T Auge and V V Zaykov ldquoOriginof chromite in mafic-ultramafic-hosted hydrothermal massivesulfides from the Main Uralian Fault South Urals RussiardquoLithos vol 70 no 1-2 pp 39ndash59 2003
[15] D M Evans ldquoMetamorphic modifications of the Muremeramafic-ultramafic intrusions eastern Burundi and their effecton chromite compositionsrdquo Journal of African Earth Sciencesvol 101 pp 19ndash34 2015
[16] T Yamanaka K Maeto H Akashi et al ldquoShallow submarinehydrothermal activity with significant contribution of mag-matic water producing talc chimneys in the Wakamiko CraterofKagoshimaBay southernKyushu Japanrdquo Journal of Volcanol-ogy and Geothermal Research vol 258 pp 74ndash84 2013
[17] B Moine J P Fortune P Moreau and F Viguier ldquoComparativemineralogy geochemistry and conditions of formation of twometasomatic talc and chlorite deposits Trimouns PyreneesFrance and Rabenwald eastern Alps Austriardquo Economic Geol-ogy vol 84 no 5 pp 1398ndash1416 1989
[18] W Prochaska ldquoGeochemistry and genesis of Austrian talcdepositsrdquo Applied Geochemistry vol 4 no 5 pp 511ndash525 1989
[19] P de Parseval S Jiang F Fontan R Wang F Martin and JFreeet ldquoGeology and ore genesis of the Trimouns talc-chloriteore deposit Pyrenees Francerdquo Acta Petrologica Sinica vol 20no 4 pp 877ndash886 2004
[20] A C Gondim and S Jiang ldquoGeologic characteristics and gene-ticmodels for the talc deposits in Parana andBahia BrazilrdquoActaPetrologica Sinica vol 20 no 4 pp 829ndash836 2004
[21] P Boulvais P de Parseval A DrsquoHulst and P Paris ldquoCarbonatealteration associated with talc-chlorite mineralization in theeastern Pyrenees with emphasis on the St Barthelemy MassifrdquoMineralogy and Petrology vol 88 no 3-4 pp 499ndash526 2006
[22] G R Davies and L B Smith Jr ldquoStructurally controlled hydro-thermal dolomite reservoir facies an overviewrdquoAAPG Bulletinvol 90 no 11 pp 1641ndash1690 2006
[23] J Lonnee and H G Machel ldquoPervasive dolomitization withsubsequent hydrothermal alteration in theClarke Lake gas field
Middle Devonian Slave Point Formation British ColumbiaCanadardquo AAPG Bulletin vol 90 no 11 pp 1739ndash1761 2006
[24] J A Luczaj ldquoEvidence against the Dorag (mixing-zone) modelfor dolomitization along theWisconsin arch - A case for hydro-thermal diagenesisrdquo AAPG Bulletin vol 90 no 11 pp 1719ndash1738 2006
[25] L B Smith Jr ldquoOrigin and reservoir characteristics of UpperOrdovician Trenton-Black River hydrothermal dolomite reser-voirs in New YorkrdquoAAPG Bulletin vol 90 no 11 pp 1691ndash17182006
[26] J Parnell ldquoDevonianMagadi-type cherts in theOrcadian BasinScotlandrdquo Journal of Sedimentary Petrology vol 56 no 4 pp495ndash500 1986
[27] J M Garcıa-Ruiz ldquoCarbonate precipitation into alkaline silica-rich environmentsrdquo Geology vol 26 no 9 pp 843ndash846 1998
[28] J Zhang W Hu Y Qian et al ldquoFormation of saddle dolomitesin Upper Cambrian carbonates western Tarim Basin (north-west China) implications for fault-related fluid flowrdquo Marineand Petroleum Geology vol 26 no 8 pp 1428ndash1440 2009
[29] J M McKinley R H Worden and A H Ruffell ldquoContactdiagenesis the effect of an intrusion on reservoir quality in thetriassic sherwood sandstone group Northern Irelandrdquo Journalof Sedimentary Research vol 71 no 3 pp 484ndash495 2001
[30] S Dong D Chen H Qing et al ldquoHydrothermal alteration ofdolostones in the Lower Ordovician Tarim Basin NW Chinamultiple constraints from petrology isotope geochemistry andfluid inclusion microthermometryrdquo Marine and PetroleumGeology vol 46 pp 270ndash286 2013
[31] V Madrucci C W D D Anjos R A Spadini D B Alvesand S M C Anjos ldquoAuthigenic magnesian clays in carbonatereservoirs in Brazilrdquo in Proceedings of the 15th International ClayConference Rio De Janeiro Brazil 2013
[32] C H Scholz ldquoEarthquakes and friction lawsrdquo Nature vol 391no 6662 pp 37ndash42 1998
[33] A M Schleicher B A Van Der Pluijm J G Solum andL N Warr ldquoOrigin and significance of clay-coated fracturesin mudrock fragments of the SAFOD borehole (ParkfieldCalifornia)rdquoGeophysical Research Letters vol 33 no 16 ArticleID L16313 2006
[34] A M Schleicher B A van der Pluijm and L N Warr ldquoNano-coatings of clay and creep of the San Andreas fault at ParkfieldCaliforniardquo Geology vol 38 no 7 pp 667ndash670 2010
[35] C Collettini C Viti S A F Smith and R E HoldsworthldquoDevelopment of interconnected talc networks and weakeningof continental low-angle normal faultsrdquo Geology vol 37 no 6pp 567ndash570 2009
[36] F Tornos and B F Spiro ldquoThe geology and isotope geochem-istry of the talc deposits of Puebla de Lillo (Cantabrian zonenorthern Spain)rdquo Economic Geology vol 95 no 6 pp 1277ndash1296 2000
[37] L Hecht R Freiberger H A Gilg G Grundmann and Y AKostitsyn ldquoRare earth element and isotope (C O Sr) charac-teristics of hydrothermal carbonates genetic implications fordolomite-hosted talc mineralization at Gopfersgrun (Fichtelge-birge Germany)rdquo Chemical Geology vol 155 no 1-2 pp 115ndash130 1999
[38] R Sharma P Joshi and P D Pant ldquoThe role of fluids inthe formation of talc deposits of Rema area Kumaun LesserHimalayardquo Journal of the Geological Society of India vol 73 no2 pp 237ndash248 2009
12 Geofluids
[39] P De Parseval B Moine J P Fortune and J Ferret ldquoFluid-mineral interactions at the origin of the Trimouns talc andchlorite deposit (Pyrenees France)rdquo in Current Research inGeology Applied to Ore Deposits P Fenoll Hach-Ali J Torrez-Ruiz and F Gervilla Eds pp 205ndash209 University of GranadaGranada Granada Spain 1993
[40] M C Boiron P Boulvais M Cathelineau D Banks N Cal-vayrac and G Hubert ldquoFluid circulation at the origin of thetrimouns talc deposit (Pyrenees France)rdquo in Proceedings of the18th Meeting of European Current Research on Fluid InclusionsSiena Italy 2005
[41] P Bayliss andA A Levhinson ldquoLow temperature hydrothermalsynthesis from dolomite or calcite quartz and kaoliniterdquo Claysand Clay Minerals vol 19 no 2 pp 109ndash114 1971
[42] G Skippen ldquoAn experimental model for low pressure meta-morphism of siliceous dolomitic marblerdquo American Journal ofScience vol 274 no 5 pp 487ndash509 1974
[43] J Slaughter D M Kerrick and V J Wall ldquoExperimen-tal and thermodynamic study of equilibria in the systemCaOndashMgOndashSiO
2ndashH2OndashCO
2rdquoAmerican Journal of Science vol
275 pp 143ndash162 1975[44] R G Eggert and D M Kerrick ldquoMetamorphic equilibria in the
siliceous dolomite system 6 kbar experimental data and geo-logic implicationsrdquo Geochimica et Cosmochimica Acta vol 45no 7 pp 1039ndash1049 1981
[45] Z Zhang and Z Duan ldquoPrediction of the PVT properties ofwater over wide range of temperatures and pressures frommolecular dynamics simulationrdquo Physics of the Earth andPlanetary Interiors vol 149 no 3-4 pp 335ndash354 2005
[46] I-M Chou Y Song and R C Burruss ldquoA newmethod for syn-thesizing fluid inclusions in fused silica capillaries containingorganic and inorganic materialrdquo Geochimica et CosmochimicaActa vol 72 no 21 pp 5217ndash5231 2008
[47] I-M Chou R C Burruss and W J Lu ldquoA new optical cellfor spectroscopic studies of geologic fluids at pressures up to100MPardquo in Advances in High-Pressure Technology for Geo-physical Applications J Chen YWang T S Duffy G Shen andL F Dobrzhinetakaya Eds pp 475ndash485 Elsevier AmsterdamNetherlands 2005
[48] K M Rosso and R J Bodnar ldquoMicrothermometric and Ramanspectroscopic detection limits of CO
2in fluid inclusions and the
Raman spectroscopic characterization of CO2rdquo Geochimica et
Cosmochimica Acta vol 59 no 19 pp 3961ndash3975 1995[49] H M Lamadrid Geochemistry of fluid-rock processes [Doctoral
dissertation] Virginia Polytechnic Institute and State Univer-sity Blacksburg VA USA 2016
[50] J H Parker D W Feldman and M Ashkin ldquoRaman scatteringby silicon and germaniumrdquo Physical Review vol 155 no 3 pp712ndash714 1967
[51] Y V Shvarov ldquoAlgorithmization of the numeric equilibriummodeling of dynamic geochemical processesrdquo GeochemistryInternational vol 37 no 6 pp 571ndash576 1999
[52] R B Wright and C H Wang ldquoDensity effect on the Fermiresonance in gaseous CO
2by Raman scatteringrdquoThe Journal of
Chemical Physics vol 58 no 7 pp 2893ndash2895 1973[53] XWang I-M ChouWHu R C Burruss Q Sun and Y Song
ldquoRaman spectroscopic measurements of CO2density experi-
mental calibration with high-pressure optical cell (HPOC) andfused silica capillary capsule (FSCC) with application to fluidinclusion observationsrdquo Geochimica et Cosmochimica Acta vol75 no 14 pp 4080ndash4093 2011
[54] H R Gordon and T K McCubbin Jr ldquoThe 28-micron bandsof CO
2rdquo Journal of Molecular Spectroscopy vol 19 no 1ndash4 pp
137ndash154 1966[55] T Azbej M J Severs B G Rusk and R J Bodnar ldquoIn situ
quantitative analysis of individual H2O-CO
2fluid inclusions by
laser Raman spectroscopyrdquo Chemical Geology vol 237 no 3-4pp 255ndash263 2007
[56] Y Song I M Chou W Hu B Robert and W Lu ldquoCO2
density-raman shift relation derived from synthetic inclusionsin fused silica capillaries and its applicationrdquo Acta GeologicaSinica (English Edition) vol 83 pp 932ndash938 2009
[57] Z Pan I-M Chou and R C Burruss ldquoHydrolysis of polycar-bonate in sub-critical water in fused silica capillary reactor within situ Raman spectroscopyrdquo Green Chemistry vol 11 no 8 pp1105ndash1107 2009
[58] M L Frezzotti F Tecce and A Casagli ldquoRaman spectroscopyfor fluid inclusion analysisrdquo Journal of Geochemical Explorationvol 112 pp 1ndash20 2012
[59] E L Shock and H C Helgeson ldquoCalculation of the thermo-dynamic and transport properties of aqueous species at highpressures and temperatures correlation algorithms for ionicspecies and equation of state predictions to 5 kb and 1000∘CrdquoGeochimica et Cosmochimica Acta vol 52 no 8 pp 2009ndash20361988
[60] O S Pokrovsky SVGolubev J Schott andACastillo ldquoCalcitedolomite and magnesite dissolution kinetics in aqueous solu-tions at acid to circumneutral pH 25 to 150∘C and 1 to 55 atmpCO2 New constraints on CO
2sequestration in sedimentary
basinsrdquo Chemical Geology vol 265 no 1-2 pp 20ndash32 2009[61] YGarrabos R Tufeu B LeNeindre G Zalczer andD Beysens
ldquoRayleigh andRaman scattering near the critical point of carbondioxiderdquo The Journal of Chemical Physics vol 72 no 8 pp4637ndash4651 1979
[62] J H Nicola J F Scott R M Couto andMM Correa ldquoRamanspectra of dolomite [CaMg(CO
3)2]rdquo Physical Review B vol 14
no 10 pp 4676ndash4678 1976[63] S Gunasekaran G Anbalagan and S Pandi ldquoRaman and
infrared spectra of carbonates of calcite structurerdquo Journal ofRaman Spectroscopy vol 37 no 9 pp 892ndash899 2006
[64] G J Rosasco and J J Blaha ldquoRaman microprobe spectra andvibrationalmode assignments of talcrdquoApplied Spectroscopy vol34 no 2 pp 140ndash144 1980
[65] V Trommsdorff and B W Evans ldquoAntigorite-ophicarbo-nates phase relations in a portion of the system CaOndashMgOndashSiO2ndashH2OndashCO
2rdquo Contributions to Mineralogy and Petrology
vol 60 no 1 pp 39ndash56 1977[66] V Trommsdorff and J A D Connolly ldquoConstraints on phase
diagram topology for the systemCaOndashMgOndashSiO2ndashCO2ndashH2Ordquo
Contributions to Mineralogy and Petrology vol 104 no 1 pp 1ndash7 1990
[67] B S Van Gosen H A Lowers S J Sutley and C A GentldquoUsing the geologic setting of talc deposits as an indicator ofamphibole asbestos contentrdquo Environmental Geology vol 45no 7 pp 920ndash939 2004
[68] W Johannes ldquoAn experimental investigation of the systemMgO-SiO
2-H2O-CO
2rdquo American Journal of Science vol 267
no 9 pp 1083ndash1104 1969[69] E S Schandl and M P Gorton ldquoHydrothermal alteration and
CO2metasomatism (natural carbon sequestration) of komati-
ites in the south-western Abitibi greenstone beltrdquo CanadianMineralogist vol 50 no 1 pp 129ndash146 2012
Geofluids 13
[70] B W Evans and S Guggenheim ldquoTalc phyrophyllite andrelated mineralsrdquo in Reviews in Mineralogy S W Bailey Edvol 19 pp 225ndash294 1988
[71] B Velde ldquoExperimental pseudomorphism of diopside by talcand serpentine in (Ni Mg)Cl
2aqueous solutionsrdquo Geochimica
et Cosmochimica Acta vol 52 no 2 pp 415ndash424 1988[72] A E Williams-Jones C Normand H Clark Vali Jr R F
Martin A Dufresne and Nayebzadeh A ldquoControls of amphi-bole formation in chrysotile from the Jeffrey Mine AsbestosQuebecrdquo inTheHealth Effects Effects of Chrysotile Asbestos R PNolan AM LangerM RossWicks F J andMartin F R Edsvol 5 pp 89ndash104 The Mineralogical Association of CanadaQuebec Quebec Canada 2001
[73] B W Evans ldquoThe serpentinite multisystem revisited chrysotileis metastablerdquo International Geology Review vol 46 no 6 pp479ndash506 2004
[74] I Gunnarsson and S Arnorsson ldquoAmorphous silica solubilityand the thermodynamic properties of H
4SiO∘4in the range of
0∘ to 350∘C at Psatrdquo Geochimica et Cosmochimica Acta vol 64no 13 pp 2295ndash2307 2000
[75] M W Bodine Jr ldquoTrioctahedral clay mineral assemblages inPaleozoic marine evaporite rocksrdquo in Proceedings of the Pre-sented in the Sixth International Symposium on Salt vol 1 pp267ndash284 Toronto Canada 1983
[76] W Schreyer and K Abraham ldquoThree-stage metamorphic his-tory of a whiteschist from Sar e Sang Afghanistan as part ofa former evaporite depositrdquo Contributions to Mineralogy andPetrology vol 59 no 2 pp 111ndash130 1976
[77] T Angerer and S G Hagemann ldquoThe BIF-hosted high-gradeiron ore deposits in the archean koolyanobbing greenstonebelt Western Australia structural control on synorogenic-and weathering-related magnetite- hematite- and goethite-rich iron orerdquo Economic Geology vol 105 no 5 pp 917ndash9452010
[78] P Duuring and S Hagemann ldquoLeaching of silica bands andconcentration of magnetite in Archean BIF by hypogene fluidsBeebyn Fe ore deposit Yilgarn Craton Western AustraliardquoMineralium Deposita vol 48 no 3 pp 341ndash370 2013
[79] D Shin and I Lee ldquoFluid inclusions and their stable isotopegeochemistry of the carbonate-hosted talc deposits near theCretaceous Muamsa Granite South Koreardquo Geochemical Jour-nal vol 40 no 1 pp 69ndash85 2006
[80] P G Novgorodov ldquoSolubility of quartz in anH2OndashCO
2mixture
at 700 degrees C and pressures of 3 and 5 kbarsrdquoGeokhimiya pp1484ndash1489 1975
[81] T M Gerlach ldquoChemical characteristics of the volcanic gasesfrom Nyiragongo lava lake and the generation of CH
4-rich
fluid inclusions in alkaline rocksrdquo Journal of Volcanology ampGeothermal Research vol 8 no 2-4 pp 177ndash189 1980
[82] J V Walther and P M Orville ldquoVolatile production and trans-port in regional metamorphismrdquo Contributions to Mineralogyand Petrology vol 79 no 3 pp 252ndash257 1982
[83] W F Giggenbach ldquoThe origin and evolution of fluids inmagmatic-hydrothermal systemsrdquo in Geochemistry of Hydro-thermalOreDeposits H L Barnes Ed pp 737ndash796WileyNewYork NY USA 3 edition 1997
[84] J B Lowenstern ldquoCarbon dioxide in magmas and implicationsfor hydrothermal systemsrdquoMineralium Deposita vol 36 no 6pp 490ndash502 2001
[85] R Kerrich and W S Fyfe ldquoThe gold-carbonate associationsource of CO
2 and CO
2fixation reactions in Archaean lode
depositsrdquo Chemical Geology vol 33 no 1ndash4 pp 265ndash294 1981
[86] P I Nabelek ldquoCalc-silicate reactions and bedding-controlledisotopic exchange in the Notch Peak aureole Utah implicationsfor differential fluid fluxes with metamorphic graderdquo Journal ofMetamorphic Geology vol 20 no 4 pp 429ndash440 2002
[87] P I Nabelek ldquoFluid evolution and kinetics of metamorphicreactions in calc-silicate contact aureoles - From H
2O to CO
2
and backrdquo Geology vol 35 no 10 pp 927ndash930 2007[88] H G Machel ldquoBacterial and thermochemical sulfate reduction
in diagenetic settings - old and new insightsrdquo SedimentaryGeology vol 140 no 1-2 pp 143ndash175 2001
[89] L Stalker P Farrimond and S R Larter ldquoWater as an oxygensource for the production of oxygenated compounds (includingCO2precursors) during kerogen maturationrdquo Organic Geo-
chemistry vol 22 no 3-5 pp 477ndashIN4 1994[90] Z K Shipton J P Evans D Kirschner P T Kolesar A P
Williams and J Heath ldquoAnalysis of CO2leakage through lsquolow-
permeabilityrsquo faults from natural reservoirs in the ColoradoPlateau east-central Utahrdquo Geological Society Special Publica-tion vol 233 pp 43ndash58 2004
[91] J Byerlee ldquoFriction overpressure and fault normal compres-sionrdquo Geophysical Research Letters vol 17 no 12 pp 2109ndash21121990
[92] C Morrow B Radney and J Byerlee ldquoChapter 3 frictionalstrength and the effective pressure law of montmorillonite andlllite claysrdquo International Geophysics vol 51 no C pp 69ndash881992
[93] C A Morrow D E Moore and D A Lockner ldquoThe effectof mineral bond strength and adsorbed water on fault gougefrictional strengthrdquo Geophysical Research Letters vol 27 no 6pp 815ndash818 2000
[94] D A Lockner C Morrow D Moore and S Hickman ldquoLowstrength of deep San Andreas fault gouge from SAFOD corerdquoNature vol 472 no 7341 pp 82ndash86 2011
[95] D EMoore andM J Rymer ldquoTalc-bearing serpentinite and thecreeping section of the San Andreas faultrdquo Nature vol 448 no7155 pp 795ndash797 2007
[96] DH Zenger ldquoDiscussion lsquoOn the formation and occurrence ofsaddle dolomitersquordquo Journal of Sedimentary Petrology vol 51 no4 pp 1350ndash1352 1981
[97] DAKatzG P Eberli P K Swart andL B Smith Jr ldquoTectonic-hydrothermal brecciation associated with calcite precipitationand permeability destruction in Mississippian carbonate reser-voirs Montana and Wyomingrdquo AAPG Bulletin vol 90 no 11pp 1803ndash1841 2006
[98] M Esteban and C Taberner ldquoSecondary porosity developmentduring late burial in carbonate reservoirs as a result of mixingandor cooling of brinesrdquo Journal of Geochemical Explorationvol 78-79 pp 355ndash359 2003
[99] H G MacHel ldquoInvestigations of burial diagenesis in carbonatehydrocarbon reservoir rocksrdquoGeoscience Canada vol 32 no 3pp 103ndash128 2005
[100] J A Sagan and B S Hart ldquoThree-dimensional seismic-baseddefinition of fault-related porosity development Trenton-BlackRiver interval Saybrook Ohiordquo AAPG Bulletin vol 90 no 11pp 1763ndash1785 2006
[101] F Xing and S Li ldquoGenesis and environment characteristics ofdolomite-hosted quartz and its significance for hydrocarbonexploration in Keping Area Tarim Basin Chinardquo Journal ofEarth Science vol 23 no 4 pp 476ndash489 2012
[102] L Yun and Z Cao ldquoHydrocarbon enrichment pattern andexploration potential of the Ordovician in Shunnan area TarimBasinrdquo Oil and Gas Geology vol 35 no 6 pp 788ndash797 2014
14 Geofluids
[103] Y Li N Ye X Yuan Q Huang B Su and R Zhou ldquoGeologicaland geochemical characteristics of silicified hydrothermal fluidsin Well Shunnan 4 Tarim Basinrdquo Oil and Gas Geology vol 36no 6 pp 934ndash944 2015
[104] L Qi ldquoOil and gas breakthrough in ultra-deep Ordoviciancarbonate formations in Shuntuoguole uplift Tarim BasinrdquoChina Petroleum Exploration vol 21 no 3 pp 38ndash51 2016 (inChinese with English abstract)
[105] H R Qing ldquoAn introduction of petrology and diagenesis ofultra-deep water carbonate reservoirs from the Atlantic Oceanoffshore Brazilrdquo 2017 Oral presentation at Wuxi Institute ofPetroleum Geology of SINOPEC Wuxi China
[106] G J Simandl and S Paradisl ldquoCarbonate-hosted talcrdquo SelectedBritish ColumbiaMineral Deposit Profiles vol 3 pp 35ndash38 1999
[107] Y K Kharaka D R Cole S D Hovorka W D Gunter K GKnauss and BM Freifeld ldquoGas-water-rock interactions in FrioFormation following CO
2injection implications for the storage
of greenhouse gases in sedimentary basinsrdquoGeology vol 34 no7 pp 577ndash580 2006
[108] Z Duan and D Li ldquoCoupled phase and aqueous speciesequilibrium of the H
2OndashCO
2ndashNaClndashCaCO
3system from 0 to
250∘C 1 to 1000 bar with NaCl concentrations up to saturationof haliterdquo Geochimica et Cosmochimica Acta vol 72 no 20 pp5128ndash5145 2008
[109] M R Giles and J DMarshall ldquoConstraints on the developmentof secondary porosity in the subsurface re-evaluation of pro-cessesrdquoMarine and PetroleumGeology vol 3 no 3 pp 243ndash2551986
[110] O S Pokrovsky S V Golubev and J Schott ldquoDissolution kinet-ics of calcite dolomite and magnesite at 25∘C and 0 to 50 atmpCO2rdquo Chemical Geology vol 217 no 3-4 pp 239ndash255 2005
[111] P Cao Z T Karpyn and L Li ldquoThe role of host rock pro-perties in determining potential CO
2migration pathwaysrdquo
International Journal of Greenhouse Gas Control vol 45 pp 18ndash26 2016
[112] M D Fishburn ldquoSignificant results of deep drilling at ElkHills Kern County Californiardquo in Structure Stratigraphy andHydrocarbon Occurrences of the San Joaquin Basin CaliforniaG K Kuespert and S A Reid Eds vol 64 pp 157ndash167 PacificSections Society of Economic Paleontologists and Mineralo-gists and American Association of Petroleum Geologists 1990
[113] E Povoden M Horacek and R Abart ldquoContact metamor-phism of siliceous dolomite and impure limestones from theWerfen formation in the eastern Monzoni contact aureolerdquoMineralogy and Petrology vol 76 no 1-2 pp 99ndash120 2002
[114] S Yuan I-M Chou R C Burruss X Wang and J Li ldquoDispro-portionation and thermochemical sulfate reduction reactions inSndashH2OndashCH
4and SndashD
2OndashCH
4systems from 200 to 340∘C at
elevated pressuresrdquo Geochimica et Cosmochimica Acta vol 118pp 263ndash275 2013
[115] X Wang I-M Chou W Hu and R C Burruss ldquoIn situ obser-vations of liquid-liquid phase separation in aqueous MgSO
4
solutions geological and geochemical implicationsrdquo Geochim-ica et Cosmochimica Acta vol 103 pp 1ndash10 2013
[116] X Wang Y Wan W Hu et al ldquoIn situ observations of liquid-liquid phase separation in aqueous ZnSO
4solutions at tem-
peratures up to 400∘C Implications for Zn2+ndashSO2minus4
[117] X Wang IM Chou W Hu Y Wan and Z Li ldquoPropertiesof lithium under hydrothermal conditions revealed by in situ
Raman spectroscopic characterization of Li2O-SO
3-H2O(D2O)
systems at temperatures up to 420∘Crdquo Chemical Geology vol451 pp 104ndash115 2017
[118] L Shang I-M Chou W Lu R C Burruss and Y ZhangldquoDetermination of diffusion coefficients of hydrogen in fusedsilica between 296 and 523 K by Raman spectroscopy and appli-cation of fused silica capillaries in studying redox reactionsrdquoGeochimica et CosmochimicaActa vol 73 no 18 pp 5435ndash54432009
[119] M Dargent J Dubessy L Truche E F Bazarkina C Nguyen-Trung and P Robert ldquoExperimental study of uranyl(VI) chlo-ride complex formation in acidic LiCl aqueous solutions underhydrothermal conditions (T = 21∘Cndash350∘C Psat) using Ramanspectroscopyrdquo European Journal ofMineralogy vol 25 no 5 pp765ndash775 2013
[120] YWanXWangWHu and I-MChou ldquoRaman spectroscopicobservations of the ion association between Mg2+ and SO2minus
4
in MgSO4-saturated droplets at temperatures of le380∘Crdquo The
Journal of Physical Chemistry A vol 119 no 34 pp 9027ndash90362015
[121] Y Wan X Wang W Hu I M Chou Y Chen and Z Xu ldquoInsitu optical and Raman spectroscopic observations of the effectsof pressure and fluid composition on liquidliquid phase separa-tion in aqueous cadmium sulfate solutions (=400∘C 50MPa)with geological and geochemical implicationsrdquo Geochimica etCosmochimica Acta vol 211 pp 133ndash152 2017
[122] W L Marshall ldquoAmorphous silica solubilitiesmdashI Behavior inaqueous sodium nitrate solutions 25ndash300∘C 0ndash6 molalrdquo Geo-chimica et Cosmochimica Acta vol 44 no 7 pp 907ndash913 1980
[123] C-T A Chen andW LMarshall ldquoAmorphous silica solubilitiesIV Behavior in pure water and aqueous sodium chloridesodium sulfate magnesium chloride and magnesium sulfatesolutions up to 350∘Crdquo Geochimica et Cosmochimica Acta vol46 no 2 pp 279ndash287 1982
[124] B A Fleming and D A Crerar ldquoSilicic acid ionization and cal-culation of silica solubility at elevated temperature and pHapplication to geothermal fluid processing and reinjectionrdquoGeothermics vol 11 no 1 pp 15ndash29 1982
Figure 7 SEM micrographs and EDS analyses of the solid relicts in an FSCC containing dolomite and water after heating at 200∘C for sim60days (a b) Honeycomb-like talc (c) dolomite grains with smooth edges and EDS result of talc (yellow arrow) (d) euhedral calcite formed inthe relicts (white arrow) and cylindrical talc growing on the inner surface of the tube (yellow arrow)
further introduction of SiO2 will make talc stable relativeto serpentine [70ndash73] Considering the fact that talc wascharacterized as the product of Mg-silicate mineral in the200∘C experiment via reaction (1) we speculate that whilenot detected byXRD talc also formed below 200∘C sinceCO
2
was generated during the experiment (see above)
33 Thermodynamic Calculations Due to the limits of theUnithermdatabase we used aqueous silica as the SiO
2species
that participated in the reaction Considering that the solu-bility of amorphous silica was high at elevated temperatures[74] the calculated results should approximate the conditionsof the experiments The Gibbs free energy (Δ119866) of formationfor talc from CaMg(CO3)2 aqueous SiO2 and H
2O at the
pressure and temperature of interest are given in Table 3 TheΔ119866 of reaction decreases with increasing temperature at thesaturation pressure This indicates that the reaction is morefavorable at higher temperatures The Δ119866 becomes negativeat 119879 ge 80∘C which implies that the formation of product talcfrom dolomite and a silica-rich fluid is thermodynamicallyfavored However this reaction may not commence untileven higher temperatures are reached due to the probableinitial kinetic barrier to the reaction These thermodynamiccalculations support the implication from the experimentalresults that talc formation can occur at temperatures above100∘C
4 Discussion
41 Implications for the Formation of Mg-Carbonate-HostedTalc Geologically Prochaska [18] grouped the talc depositsinto five types (1) talc related to ultramafics (eg [13ndash15]) (2)Mg-carbonate-hosted talc (eg [20 37]) (3) metamorphictalc (eg [75 76]) (4) talc related to banded iron forma-tions (mostly minnesotaite [77 78]) and (5) secondary talcdeposits [18] The most economically viable of these depositsare usually related to the metamorphic reaction between anMg-carbonate infiltrated by a silica-rich hydrothermal fluid[18 20 21 37] Intense fractures that increase the permeabilityof geological fluid flow generally develop near such deposits[18 20 21 37 38]
Investigating the formation temperature of talc canimprove our understanding of its mineralization processThis has previously been done using several methods Theseinclude microthermometric measurements of relevant fluidinclusions (eg [39 40 79]) and calculations using talcndashdolo-mite oxygen isotope thermometry assuming that themineralpairs achieve oxygen isotope equilibrium [21 36] In additionthe phase diagram of the CaOndashMgOndashSiO2ndashCO2ndashH2O sys-tem has often been referred to for evaluating the formationtemperature of talc [5 35] The diagram was establishedbased on hydrothermal experiments geological case studiesand thermodynamic calculations [4 5 43 44] However the
8 Geofluids
Table 3 The Gibbs free energies of the reaction 3CaMg(CO3)2+ 4SiO
2(aq) + H
2O = Mg
3(Si4O10)(OH)
2+ 3CaCO
3+ 3CO
2at the
temperatures of interest and their corresponding saturation pressures
Temperature (∘C) Δ119866a (kJmol) 119875satb (bar) Temperature (∘C) ΔG (kJmol) 119875sat (bar)
25 7709 0032 100 ndash7083 101450 4663 0124 110 ndash9951 143460 2771 0199 120 ndash12938 198770 0609 0312 130 ndash16032 270380 ndash1778 0474 140 ndash19223 361590 ndash4351 0702 150 ndash22502 4761aΔ119866 refers to the Gibbs free energy of the reaction b119875sat represents the corresponding saturation pressures which are calculated based on the thermodynamicmodel proposed by Zhang and Duan [45]
experiments used to chart out this systemhave been generallyconducted at gt250∘C [4 41ndash44] The reaction path of thephase diagram at low temperatures was mainly establishedthrough thermodynamic calculations implying the need fortalc forming experiments at temperatures below 250∘C
Some geological case studies attribute low talc mineral-ization temperatures (lt200∘C) derived from adjacent talc anddolomite oxygen isotope thermometry to actually reflect iso-topic disequilibrium [36] This study shows that talc depositscan still form at temperatures below 200∘C on geologicaltime scales especially if the product CO
2can be released
(cf reaction (1)) However large-scale talc mineralization ismore likely to form at higher temperatures (eg 250ndash400∘C)Firstly PCO
2controls the lower thermal limit of talc stability
The onset temperature of the transformation increases withincreasing PCO
2 because CO
2is a product of the metamor-
phic reaction (1) and its presence greatly decreases the solu-bility of SiO
2in the fluid [80] CO
2is a common component
in geological fluids and can be either released from magmas(eg [81ndash84]) or generated from the hydrothermal alterationof carbonate (eg [85ndash87]) The oxidation (eg [88]) andhydrothermal maturation of organic matter are also naturalsources of CO
2[89 90]Therefore talcmineralization should
occur at relatively high temperatures in the presence of CO2
Secondly as our results have shown the reaction rate forreaction (1) increases sharply with increasing temperaturefacilitating talc deposits to form at higher temperatures
This study can also contribute to understanding the faultweakening mechanism in the upper crust The elastic strainaccumulation along a fault can be released through a suddenseismic slip (earthquake) or aseismic creep slip [32] A lowerfrictional coefficient for a fault will facilitate stable creepweakening the fault and suppressing the occurrence of strongearthquakes [35]The frictional coefficient of a fault generallydecreases with increasing temperature [35] Therefore faultsare likely to beweakened due to high temperatures in the deepcrust but not in the cool shallow crust The pervasive distri-bution of clay minerals along faults has also been thought toweaken faults [33ndash35 91ndash94] because layered clay mineralsexhibit much lower frictional coefficients than otherminerals[95] For example talc discovered along the SanAndreas faultzone is responsible for helping in aiding slippage along thefault [35 95] As shown here dolomite could react at le200∘Cwith silica-rich fluids traveling along fault planes to form
talc and hence might be an important mechanism of faultweakening in carbonate sequences in the upper crust
42 Implications for Hydrothermal Dolomite Reservoir Re-search Carbonate rock is the main type of hydrocarbonreservoir worldwide hosting over 60 of petroleum reserves[31] Dolomite hydrocarbon reservoirs are important com-prising about half of the carbonate hydrocarbon reser-voirs worldwide [96] Recent research has suggested thathydrothermal alteration can increase the porosity and per-meability of dolomite reservoirs substantially and is animportant factor affecting the development and distributionof dolomite reservoirs [24 25 97ndash101] The Tarim basin isone of the most important petroliferous basins in China andcontains a lower Palaeozoic carbonate series which is alsoan important hydrocarbon reservoir Recent exploration hasshown that silica-rich hydrothermal fluids have infiltratedthese carbonate series improving the physical properties ofthe reservoirs considerably (eg the Shunnan area of theTarim Basin [102 103]) It has been proposed that silica-richhydrothermal fluids were transported through extensionalfaults from the deep strata to the shallow carbonate sequencewhere they migrated laterally through porous and permeablecarbonate formations (sim6670m in the Shunnan area [104])Hydrothermal fluids originating in deep basins are generallyhot Microthermometric measurements have indicated thatthe silica-rich hydrothermal fluids in the Tarim basin reachover 200∘C [101 103] Given that the lower part of the lowerPalaeozoic sequence is mainly composed of dolomite silica-rich hydrothermal fluids could react with the dolomite toform talc and thus change the physical properties of the reser-voir Recently petrologic and diagenetic research haverevealed pervasive silicification in Early Cretaceous ultra-deep water carbonate reservoirs in the Atlantic Ocean off-shore from Brazil [105] The presence of talc calcite quartzand dolomite on the thin-section scale may indicate that thedolomite was strongly corroded by a silica-rich hydrothermalfluid
Alteration of dolomite to talcwill alsomodify the porosityand permeability of carbonate hydrocarbon reservoirs [29ndash31] The silica required for the mineral alteration can be pro-vided by either silica-rich hydrothermal fluids or silica (egquartz chert and opal) within the carbonate reservoirs [106]If SiO
2derives from quartzchert in the dolomite sequences
Geofluids 9
the hydrothermal alteration would increase the porosity ofthe dolomite reservoirs McKinley et al [29] reported thatthe total volume of minerals within a dolomite reservoir canbe reduced by 13 to 17 through the reaction betweendolomite and quartz in reaction (1) In addition the reactionbetween dolomite and silica-rich hydrothermal fluids can actas an important source of CO
2 in hydrocarbon reservoirsThepresence of CO2 can lower the pH of the formation waterand thus promote the dissolution of carbonate minerals [60107 108] increasing the porosity of the reservoirs [109ndash111]However the pore throats may be blocked by the formationof talc or other clay minerals [29 112] Therefore moredetailed factors should be considered in order to unequi-vocally evaluate the effects of silica-rich hydrothermal fluidsin dolomite reservoirs
Although talc can form from the interaction betweendolomite and silica-rich fluids at low temperatures it isseldom observed in hydrocarbon reservoirs [29 31] for thefollowing two reasons (1)A large amount of CO
2can be pro-
duced by the maturation of organic matter and the reactionbetween carbonate minerals and organic acid [98 101] Thepresence of CO
2decreases the lower thermal stability field
of talc [113] (2)The reaction path is dependent on the com-position of the hydrothermal fluid For example K+ andAl3+ are also important components of geological fluidsMontmorillonite instead of talc is more likely to form inthe presence of only a small quantity of Al3+ [41] and theformation of talc can also be inhibited by K+ [29]
43 Implications for High PndashT Experiment Using Fused SilicaCapillary Tubes as Reactors FSCCs are used to constructsynthetic fluid inclusions containing organic and inorganiccomponents [46] They offer advantages such as being inertto many components especially acids and S allowing forthe convenient synthesis of fluid inclusions and facilitatingin situ optical and Raman spectroscopic observations (eg[57 114ndash117]) Fused silica tubes can tolerate relatively hightemperatures up to 600∘C and pressures up to 300MPa As aresult FSCCs are used in many research fields For examplein addition to construction of synthetic fluid inclusions[46 53 118] FSCCs were used in studying the propertiesof hydrothermal fluids as optical and Raman spectroscopiccells [115ndash117 119ndash121] FSCCs were also used as reactorsin investigating the mechanism of thermochemical sulfatereduction [114] and the decomposition of organic matter[57]
However SiO2 in the FSCC acted as a reagent in thisstudy and was partially dissolved as indicated by the pitson the inner surface of the tube (Figures 8(a)ndash8(d)) Thedissolution of silica from FSCCs containing alkali sulfatesolutions was also observed after quenching from ge350∘C(Figures 8(e) and 8(f)) The severe dissolution of fused silicacan be ascribed to three factors (1) Amorphous silica ismore soluble than quartz especially at high temperaturesIn neutral solutions its solubility increases sharply withtemperature from 100 ppm at 20∘C to 1500 ppm at 310∘C[74 122 123] (2) Under basic conditions the solubility ofamorphous silica is greatly enhanced by the ionization ofsilicic acid (H
4SiO4+ OHminus rarr H
3SiO4
minus + H2O [124]) (3)
SiO2may act as a reagent as it did in this experiment The
presence of dissolution pits will weaken the mechanicalstrength of the silica tube In addition the presence ofdissolved silica can make the system more complicated thanexpected Therefore the solubility and reactivity of silicaunder hydrothermal conditions should be evaluated beforeFSCCs are used as reactors
5 Conclusion
The reactions in the CaMg(CO3)2ndashSiO2ndashH2O system atlow temperatures were investigated using fused silica tubesas reactors Results showed that dolomite reacted with asilica-rich fluid to form talc calcite and CO2 at le200
∘Cand low PCO2 The reaction rate increased with increasingtemperature and decreased with rising PCO2Therefore hightemperature and the presence of a conduit to release CO2 willpromote the formation of talcThis experiment has importantgeological and geochemical implications(1)Theresults confirmed themechanism of talcminerali-
zation in Mg-carbonate hosted talc deposits Dolomitereacted with silica-rich hydrothermal fluids to form talccalcite and CO
2 Talc could form at le200∘C whereas pre-
vious hydrothermal experiments examining the CaOndashMgOndashSiO2ndashCO2ndashH2O system were mainly conducted at gt250∘C
However considering the effect of temperature on thereaction rate and other geological conditions massive talcdeposits are still more likely to form at higher temperaturesThe formation of talc along a fault in a Mg-carbonateformation will also weaken the fault thus preventing strongearthquakes(2) Talc in carbonate reservoirs can indicate the activity
of silica-rich hydrothermal fluids Fluid-aided alteration ofdolomite can change the physical properties of dolomitereservoirs substantially The reaction between dolomite andquartz within the carbonate can decrease the total volume ofminerals by 13ndash17 The generation of CO2 can promotethe dissolution of carbonate minerals elsewhere under theappropriate conditions increasing the porosity and perme-ability of carbonate reservoirs However talc minerals mayblock pore throats in the reservoirs Therefore additionalfactors need to be considered when evaluating the effectsof CaMg(CO
3)2ndashSiO2ndashH2O interactions on the physical
properties of carbonate reservoirs(3) The solubility and reactivity of silica should be con-
sidered when using fused silica tubes as reactors in highPndashT experiments The dissolution of silica will increase thecomplexity of the system andweaken themechanical strengthof the tube
Conflicts of Interest
The authors declare that they have no conflicts of interest
Acknowledgments
The dolomite sample was provided by Mr Chunhua ShiMisses Yang Qu Wanlu Gao and Ye Qiu helped the authorsa lot during the micro-XRD analysis and HPOC experiment
10 Geofluids
Outer surfaceInner surface
(a) (b)In
ner s
urfa
ce
(c) (d)
Inner surface
(e) (f)
Figure 8 SEM images of the inner surface of the silica tube (a) Smooth inner surface before the reaction (b) magnification of the squarearea shown in (a) (c) dissolution pits on the inner surface after heating at 200∘C for sim60 days (d) magnification of (c) severe erosion of thesilica on the inner surface of FSCCs containing (e) 10m Na
2SO4and (f) 10m Li
2SO4after heating at 350∘C for 1 h
Dr Rui Wang and Miss Siyu Hu are also thanked for theirhelp in the thermodynamic calculations of the reactionsThis work was financially supported by the National NaturalScience Foundation of China (Grant nos 41230312 and41573054) I-Ming Chou is thankful for the support of theKnowledge Innovation Program (SIDSSE-201302) and theHadal-trench Research Program (XDB06060100) of ChineseAcademy of Sciences
References
[1] L D Meinert ldquoSkarns and skarn depositsrdquo Geoscience Canadavol 19 no 4 pp 145ndash162 1992
[2] L D Meinert G M Dipple and S Nicolescu ldquoWorld skarndepositsrdquo Economic Geology 100th Anniversary Volume pp299ndash336 2005
[3] Y Yao J Chen J Lu R Wang and R Zhang ldquoGeology andgenesis of the Hehuaping magnesian skarn-type cassiterite-sulfide deposit Hunan Province Southern ChinardquoOre GeologyReviews vol 58 no C pp 163ndash184 2014
[4] T M Gordon and H J Greenwood ldquoThe reaction dolomite+ quartz + water = talc + calcite + carbon dioxiderdquo AmericanJournal of Science vol 268 pp 225ndash242 1970
[5] M B Holness ldquoFluid flow paths and mechanisms of fluidinfiltration in carbonates during contact metamorphism TheBeinn an Dubhaich aureole Skyerdquo Journal of MetamorphicGeology vol 15 no 1 pp 59ndash70 1997
Geofluids 11
[6] W Heinrich S S Churakov andM Gottschalk ldquoMineral-fluidequilibria in the system CaOndashMgOndashSiO
2ndashH2OndashCO
2ndashNaCl
and the record of reactive fluid flow in contact metamorphicaureolesrdquo Contributions to Mineralogy and Petrology vol 148no 2 pp 131ndash149 2004
[7] M Wesołowski ldquoThermal decomposition of talc a reviewrdquoThermochimica Acta vol 78 no 1-3 pp 395ndash421 1984
[8] L A Perez-Maqueda A Duran and J L Perez-RodrıguezldquoPreparation of submicron talc particles by sonicationrdquoAppliedClay Science vol 28 no 1-4 pp 245ndash255 2005
[9] R L Johnson ldquoTalcrdquoAmerican Ceramic Society Bulletin vol 71pp 818ndash820 1992
[10] R L Johnson and R L Virta ldquoTalcrdquo American Ceramic SocietyBulletin vol 79 pp 79ndash81 2000
[11] M Z Abzalov ldquoChrome-spinels in gabbro-wehrlite intrusionsof the Pechenga area Kola Peninsula Russia emphasis onalteration featuresrdquo Lithos vol 43 no 3 pp 109ndash134 1998
[12] M F El-Sharkawy ldquoTalc mineralization of ultramafic affinity inthe Eastern Desert of Egyptrdquo Mineralium Deposita vol 35 no4 pp 346ndash363 2000
[13] M Franceschelli G Carcangiu A M Caredda G CrucianiI Memmi and M Zucca ldquoTransformation of cumulate maficrocks to granulite and re-equilibration in amphibolite andgreenschist facies in NE Sardinia Italyrdquo Lithos vol 63 no 1-2pp 1ndash18 2002
[14] S G Tesalina P Nimis T Auge and V V Zaykov ldquoOriginof chromite in mafic-ultramafic-hosted hydrothermal massivesulfides from the Main Uralian Fault South Urals RussiardquoLithos vol 70 no 1-2 pp 39ndash59 2003
[15] D M Evans ldquoMetamorphic modifications of the Muremeramafic-ultramafic intrusions eastern Burundi and their effecton chromite compositionsrdquo Journal of African Earth Sciencesvol 101 pp 19ndash34 2015
[16] T Yamanaka K Maeto H Akashi et al ldquoShallow submarinehydrothermal activity with significant contribution of mag-matic water producing talc chimneys in the Wakamiko CraterofKagoshimaBay southernKyushu Japanrdquo Journal of Volcanol-ogy and Geothermal Research vol 258 pp 74ndash84 2013
[17] B Moine J P Fortune P Moreau and F Viguier ldquoComparativemineralogy geochemistry and conditions of formation of twometasomatic talc and chlorite deposits Trimouns PyreneesFrance and Rabenwald eastern Alps Austriardquo Economic Geol-ogy vol 84 no 5 pp 1398ndash1416 1989
[18] W Prochaska ldquoGeochemistry and genesis of Austrian talcdepositsrdquo Applied Geochemistry vol 4 no 5 pp 511ndash525 1989
[19] P de Parseval S Jiang F Fontan R Wang F Martin and JFreeet ldquoGeology and ore genesis of the Trimouns talc-chloriteore deposit Pyrenees Francerdquo Acta Petrologica Sinica vol 20no 4 pp 877ndash886 2004
[20] A C Gondim and S Jiang ldquoGeologic characteristics and gene-ticmodels for the talc deposits in Parana andBahia BrazilrdquoActaPetrologica Sinica vol 20 no 4 pp 829ndash836 2004
[21] P Boulvais P de Parseval A DrsquoHulst and P Paris ldquoCarbonatealteration associated with talc-chlorite mineralization in theeastern Pyrenees with emphasis on the St Barthelemy MassifrdquoMineralogy and Petrology vol 88 no 3-4 pp 499ndash526 2006
[22] G R Davies and L B Smith Jr ldquoStructurally controlled hydro-thermal dolomite reservoir facies an overviewrdquoAAPG Bulletinvol 90 no 11 pp 1641ndash1690 2006
[23] J Lonnee and H G Machel ldquoPervasive dolomitization withsubsequent hydrothermal alteration in theClarke Lake gas field
Middle Devonian Slave Point Formation British ColumbiaCanadardquo AAPG Bulletin vol 90 no 11 pp 1739ndash1761 2006
[24] J A Luczaj ldquoEvidence against the Dorag (mixing-zone) modelfor dolomitization along theWisconsin arch - A case for hydro-thermal diagenesisrdquo AAPG Bulletin vol 90 no 11 pp 1719ndash1738 2006
[25] L B Smith Jr ldquoOrigin and reservoir characteristics of UpperOrdovician Trenton-Black River hydrothermal dolomite reser-voirs in New YorkrdquoAAPG Bulletin vol 90 no 11 pp 1691ndash17182006
[26] J Parnell ldquoDevonianMagadi-type cherts in theOrcadian BasinScotlandrdquo Journal of Sedimentary Petrology vol 56 no 4 pp495ndash500 1986
[27] J M Garcıa-Ruiz ldquoCarbonate precipitation into alkaline silica-rich environmentsrdquo Geology vol 26 no 9 pp 843ndash846 1998
[28] J Zhang W Hu Y Qian et al ldquoFormation of saddle dolomitesin Upper Cambrian carbonates western Tarim Basin (north-west China) implications for fault-related fluid flowrdquo Marineand Petroleum Geology vol 26 no 8 pp 1428ndash1440 2009
[29] J M McKinley R H Worden and A H Ruffell ldquoContactdiagenesis the effect of an intrusion on reservoir quality in thetriassic sherwood sandstone group Northern Irelandrdquo Journalof Sedimentary Research vol 71 no 3 pp 484ndash495 2001
[30] S Dong D Chen H Qing et al ldquoHydrothermal alteration ofdolostones in the Lower Ordovician Tarim Basin NW Chinamultiple constraints from petrology isotope geochemistry andfluid inclusion microthermometryrdquo Marine and PetroleumGeology vol 46 pp 270ndash286 2013
[31] V Madrucci C W D D Anjos R A Spadini D B Alvesand S M C Anjos ldquoAuthigenic magnesian clays in carbonatereservoirs in Brazilrdquo in Proceedings of the 15th International ClayConference Rio De Janeiro Brazil 2013
[32] C H Scholz ldquoEarthquakes and friction lawsrdquo Nature vol 391no 6662 pp 37ndash42 1998
[33] A M Schleicher B A Van Der Pluijm J G Solum andL N Warr ldquoOrigin and significance of clay-coated fracturesin mudrock fragments of the SAFOD borehole (ParkfieldCalifornia)rdquoGeophysical Research Letters vol 33 no 16 ArticleID L16313 2006
[34] A M Schleicher B A van der Pluijm and L N Warr ldquoNano-coatings of clay and creep of the San Andreas fault at ParkfieldCaliforniardquo Geology vol 38 no 7 pp 667ndash670 2010
[35] C Collettini C Viti S A F Smith and R E HoldsworthldquoDevelopment of interconnected talc networks and weakeningof continental low-angle normal faultsrdquo Geology vol 37 no 6pp 567ndash570 2009
[36] F Tornos and B F Spiro ldquoThe geology and isotope geochem-istry of the talc deposits of Puebla de Lillo (Cantabrian zonenorthern Spain)rdquo Economic Geology vol 95 no 6 pp 1277ndash1296 2000
[37] L Hecht R Freiberger H A Gilg G Grundmann and Y AKostitsyn ldquoRare earth element and isotope (C O Sr) charac-teristics of hydrothermal carbonates genetic implications fordolomite-hosted talc mineralization at Gopfersgrun (Fichtelge-birge Germany)rdquo Chemical Geology vol 155 no 1-2 pp 115ndash130 1999
[38] R Sharma P Joshi and P D Pant ldquoThe role of fluids inthe formation of talc deposits of Rema area Kumaun LesserHimalayardquo Journal of the Geological Society of India vol 73 no2 pp 237ndash248 2009
12 Geofluids
[39] P De Parseval B Moine J P Fortune and J Ferret ldquoFluid-mineral interactions at the origin of the Trimouns talc andchlorite deposit (Pyrenees France)rdquo in Current Research inGeology Applied to Ore Deposits P Fenoll Hach-Ali J Torrez-Ruiz and F Gervilla Eds pp 205ndash209 University of GranadaGranada Granada Spain 1993
[40] M C Boiron P Boulvais M Cathelineau D Banks N Cal-vayrac and G Hubert ldquoFluid circulation at the origin of thetrimouns talc deposit (Pyrenees France)rdquo in Proceedings of the18th Meeting of European Current Research on Fluid InclusionsSiena Italy 2005
[41] P Bayliss andA A Levhinson ldquoLow temperature hydrothermalsynthesis from dolomite or calcite quartz and kaoliniterdquo Claysand Clay Minerals vol 19 no 2 pp 109ndash114 1971
[42] G Skippen ldquoAn experimental model for low pressure meta-morphism of siliceous dolomitic marblerdquo American Journal ofScience vol 274 no 5 pp 487ndash509 1974
[43] J Slaughter D M Kerrick and V J Wall ldquoExperimen-tal and thermodynamic study of equilibria in the systemCaOndashMgOndashSiO
2ndashH2OndashCO
2rdquoAmerican Journal of Science vol
275 pp 143ndash162 1975[44] R G Eggert and D M Kerrick ldquoMetamorphic equilibria in the
siliceous dolomite system 6 kbar experimental data and geo-logic implicationsrdquo Geochimica et Cosmochimica Acta vol 45no 7 pp 1039ndash1049 1981
[45] Z Zhang and Z Duan ldquoPrediction of the PVT properties ofwater over wide range of temperatures and pressures frommolecular dynamics simulationrdquo Physics of the Earth andPlanetary Interiors vol 149 no 3-4 pp 335ndash354 2005
[46] I-M Chou Y Song and R C Burruss ldquoA newmethod for syn-thesizing fluid inclusions in fused silica capillaries containingorganic and inorganic materialrdquo Geochimica et CosmochimicaActa vol 72 no 21 pp 5217ndash5231 2008
[47] I-M Chou R C Burruss and W J Lu ldquoA new optical cellfor spectroscopic studies of geologic fluids at pressures up to100MPardquo in Advances in High-Pressure Technology for Geo-physical Applications J Chen YWang T S Duffy G Shen andL F Dobrzhinetakaya Eds pp 475ndash485 Elsevier AmsterdamNetherlands 2005
[48] K M Rosso and R J Bodnar ldquoMicrothermometric and Ramanspectroscopic detection limits of CO
2in fluid inclusions and the
Raman spectroscopic characterization of CO2rdquo Geochimica et
Cosmochimica Acta vol 59 no 19 pp 3961ndash3975 1995[49] H M Lamadrid Geochemistry of fluid-rock processes [Doctoral
dissertation] Virginia Polytechnic Institute and State Univer-sity Blacksburg VA USA 2016
[50] J H Parker D W Feldman and M Ashkin ldquoRaman scatteringby silicon and germaniumrdquo Physical Review vol 155 no 3 pp712ndash714 1967
[51] Y V Shvarov ldquoAlgorithmization of the numeric equilibriummodeling of dynamic geochemical processesrdquo GeochemistryInternational vol 37 no 6 pp 571ndash576 1999
[52] R B Wright and C H Wang ldquoDensity effect on the Fermiresonance in gaseous CO
2by Raman scatteringrdquoThe Journal of
Chemical Physics vol 58 no 7 pp 2893ndash2895 1973[53] XWang I-M ChouWHu R C Burruss Q Sun and Y Song
ldquoRaman spectroscopic measurements of CO2density experi-
mental calibration with high-pressure optical cell (HPOC) andfused silica capillary capsule (FSCC) with application to fluidinclusion observationsrdquo Geochimica et Cosmochimica Acta vol75 no 14 pp 4080ndash4093 2011
[54] H R Gordon and T K McCubbin Jr ldquoThe 28-micron bandsof CO
2rdquo Journal of Molecular Spectroscopy vol 19 no 1ndash4 pp
137ndash154 1966[55] T Azbej M J Severs B G Rusk and R J Bodnar ldquoIn situ
quantitative analysis of individual H2O-CO
2fluid inclusions by
laser Raman spectroscopyrdquo Chemical Geology vol 237 no 3-4pp 255ndash263 2007
[56] Y Song I M Chou W Hu B Robert and W Lu ldquoCO2
density-raman shift relation derived from synthetic inclusionsin fused silica capillaries and its applicationrdquo Acta GeologicaSinica (English Edition) vol 83 pp 932ndash938 2009
[57] Z Pan I-M Chou and R C Burruss ldquoHydrolysis of polycar-bonate in sub-critical water in fused silica capillary reactor within situ Raman spectroscopyrdquo Green Chemistry vol 11 no 8 pp1105ndash1107 2009
[58] M L Frezzotti F Tecce and A Casagli ldquoRaman spectroscopyfor fluid inclusion analysisrdquo Journal of Geochemical Explorationvol 112 pp 1ndash20 2012
[59] E L Shock and H C Helgeson ldquoCalculation of the thermo-dynamic and transport properties of aqueous species at highpressures and temperatures correlation algorithms for ionicspecies and equation of state predictions to 5 kb and 1000∘CrdquoGeochimica et Cosmochimica Acta vol 52 no 8 pp 2009ndash20361988
[60] O S Pokrovsky SVGolubev J Schott andACastillo ldquoCalcitedolomite and magnesite dissolution kinetics in aqueous solu-tions at acid to circumneutral pH 25 to 150∘C and 1 to 55 atmpCO2 New constraints on CO
2sequestration in sedimentary
basinsrdquo Chemical Geology vol 265 no 1-2 pp 20ndash32 2009[61] YGarrabos R Tufeu B LeNeindre G Zalczer andD Beysens
ldquoRayleigh andRaman scattering near the critical point of carbondioxiderdquo The Journal of Chemical Physics vol 72 no 8 pp4637ndash4651 1979
[62] J H Nicola J F Scott R M Couto andMM Correa ldquoRamanspectra of dolomite [CaMg(CO
3)2]rdquo Physical Review B vol 14
no 10 pp 4676ndash4678 1976[63] S Gunasekaran G Anbalagan and S Pandi ldquoRaman and
infrared spectra of carbonates of calcite structurerdquo Journal ofRaman Spectroscopy vol 37 no 9 pp 892ndash899 2006
[64] G J Rosasco and J J Blaha ldquoRaman microprobe spectra andvibrationalmode assignments of talcrdquoApplied Spectroscopy vol34 no 2 pp 140ndash144 1980
[65] V Trommsdorff and B W Evans ldquoAntigorite-ophicarbo-nates phase relations in a portion of the system CaOndashMgOndashSiO2ndashH2OndashCO
2rdquo Contributions to Mineralogy and Petrology
vol 60 no 1 pp 39ndash56 1977[66] V Trommsdorff and J A D Connolly ldquoConstraints on phase
diagram topology for the systemCaOndashMgOndashSiO2ndashCO2ndashH2Ordquo
Contributions to Mineralogy and Petrology vol 104 no 1 pp 1ndash7 1990
[67] B S Van Gosen H A Lowers S J Sutley and C A GentldquoUsing the geologic setting of talc deposits as an indicator ofamphibole asbestos contentrdquo Environmental Geology vol 45no 7 pp 920ndash939 2004
[68] W Johannes ldquoAn experimental investigation of the systemMgO-SiO
2-H2O-CO
2rdquo American Journal of Science vol 267
no 9 pp 1083ndash1104 1969[69] E S Schandl and M P Gorton ldquoHydrothermal alteration and
CO2metasomatism (natural carbon sequestration) of komati-
ites in the south-western Abitibi greenstone beltrdquo CanadianMineralogist vol 50 no 1 pp 129ndash146 2012
Geofluids 13
[70] B W Evans and S Guggenheim ldquoTalc phyrophyllite andrelated mineralsrdquo in Reviews in Mineralogy S W Bailey Edvol 19 pp 225ndash294 1988
[71] B Velde ldquoExperimental pseudomorphism of diopside by talcand serpentine in (Ni Mg)Cl
2aqueous solutionsrdquo Geochimica
et Cosmochimica Acta vol 52 no 2 pp 415ndash424 1988[72] A E Williams-Jones C Normand H Clark Vali Jr R F
Martin A Dufresne and Nayebzadeh A ldquoControls of amphi-bole formation in chrysotile from the Jeffrey Mine AsbestosQuebecrdquo inTheHealth Effects Effects of Chrysotile Asbestos R PNolan AM LangerM RossWicks F J andMartin F R Edsvol 5 pp 89ndash104 The Mineralogical Association of CanadaQuebec Quebec Canada 2001
[73] B W Evans ldquoThe serpentinite multisystem revisited chrysotileis metastablerdquo International Geology Review vol 46 no 6 pp479ndash506 2004
[74] I Gunnarsson and S Arnorsson ldquoAmorphous silica solubilityand the thermodynamic properties of H
4SiO∘4in the range of
0∘ to 350∘C at Psatrdquo Geochimica et Cosmochimica Acta vol 64no 13 pp 2295ndash2307 2000
[75] M W Bodine Jr ldquoTrioctahedral clay mineral assemblages inPaleozoic marine evaporite rocksrdquo in Proceedings of the Pre-sented in the Sixth International Symposium on Salt vol 1 pp267ndash284 Toronto Canada 1983
[76] W Schreyer and K Abraham ldquoThree-stage metamorphic his-tory of a whiteschist from Sar e Sang Afghanistan as part ofa former evaporite depositrdquo Contributions to Mineralogy andPetrology vol 59 no 2 pp 111ndash130 1976
[77] T Angerer and S G Hagemann ldquoThe BIF-hosted high-gradeiron ore deposits in the archean koolyanobbing greenstonebelt Western Australia structural control on synorogenic-and weathering-related magnetite- hematite- and goethite-rich iron orerdquo Economic Geology vol 105 no 5 pp 917ndash9452010
[78] P Duuring and S Hagemann ldquoLeaching of silica bands andconcentration of magnetite in Archean BIF by hypogene fluidsBeebyn Fe ore deposit Yilgarn Craton Western AustraliardquoMineralium Deposita vol 48 no 3 pp 341ndash370 2013
[79] D Shin and I Lee ldquoFluid inclusions and their stable isotopegeochemistry of the carbonate-hosted talc deposits near theCretaceous Muamsa Granite South Koreardquo Geochemical Jour-nal vol 40 no 1 pp 69ndash85 2006
[80] P G Novgorodov ldquoSolubility of quartz in anH2OndashCO
2mixture
at 700 degrees C and pressures of 3 and 5 kbarsrdquoGeokhimiya pp1484ndash1489 1975
[81] T M Gerlach ldquoChemical characteristics of the volcanic gasesfrom Nyiragongo lava lake and the generation of CH
4-rich
fluid inclusions in alkaline rocksrdquo Journal of Volcanology ampGeothermal Research vol 8 no 2-4 pp 177ndash189 1980
[82] J V Walther and P M Orville ldquoVolatile production and trans-port in regional metamorphismrdquo Contributions to Mineralogyand Petrology vol 79 no 3 pp 252ndash257 1982
[83] W F Giggenbach ldquoThe origin and evolution of fluids inmagmatic-hydrothermal systemsrdquo in Geochemistry of Hydro-thermalOreDeposits H L Barnes Ed pp 737ndash796WileyNewYork NY USA 3 edition 1997
[84] J B Lowenstern ldquoCarbon dioxide in magmas and implicationsfor hydrothermal systemsrdquoMineralium Deposita vol 36 no 6pp 490ndash502 2001
[85] R Kerrich and W S Fyfe ldquoThe gold-carbonate associationsource of CO
2 and CO
2fixation reactions in Archaean lode
depositsrdquo Chemical Geology vol 33 no 1ndash4 pp 265ndash294 1981
[86] P I Nabelek ldquoCalc-silicate reactions and bedding-controlledisotopic exchange in the Notch Peak aureole Utah implicationsfor differential fluid fluxes with metamorphic graderdquo Journal ofMetamorphic Geology vol 20 no 4 pp 429ndash440 2002
[87] P I Nabelek ldquoFluid evolution and kinetics of metamorphicreactions in calc-silicate contact aureoles - From H
2O to CO
2
and backrdquo Geology vol 35 no 10 pp 927ndash930 2007[88] H G Machel ldquoBacterial and thermochemical sulfate reduction
in diagenetic settings - old and new insightsrdquo SedimentaryGeology vol 140 no 1-2 pp 143ndash175 2001
[89] L Stalker P Farrimond and S R Larter ldquoWater as an oxygensource for the production of oxygenated compounds (includingCO2precursors) during kerogen maturationrdquo Organic Geo-
chemistry vol 22 no 3-5 pp 477ndashIN4 1994[90] Z K Shipton J P Evans D Kirschner P T Kolesar A P
Williams and J Heath ldquoAnalysis of CO2leakage through lsquolow-
permeabilityrsquo faults from natural reservoirs in the ColoradoPlateau east-central Utahrdquo Geological Society Special Publica-tion vol 233 pp 43ndash58 2004
[91] J Byerlee ldquoFriction overpressure and fault normal compres-sionrdquo Geophysical Research Letters vol 17 no 12 pp 2109ndash21121990
[92] C Morrow B Radney and J Byerlee ldquoChapter 3 frictionalstrength and the effective pressure law of montmorillonite andlllite claysrdquo International Geophysics vol 51 no C pp 69ndash881992
[93] C A Morrow D E Moore and D A Lockner ldquoThe effectof mineral bond strength and adsorbed water on fault gougefrictional strengthrdquo Geophysical Research Letters vol 27 no 6pp 815ndash818 2000
[94] D A Lockner C Morrow D Moore and S Hickman ldquoLowstrength of deep San Andreas fault gouge from SAFOD corerdquoNature vol 472 no 7341 pp 82ndash86 2011
[95] D EMoore andM J Rymer ldquoTalc-bearing serpentinite and thecreeping section of the San Andreas faultrdquo Nature vol 448 no7155 pp 795ndash797 2007
[96] DH Zenger ldquoDiscussion lsquoOn the formation and occurrence ofsaddle dolomitersquordquo Journal of Sedimentary Petrology vol 51 no4 pp 1350ndash1352 1981
[97] DAKatzG P Eberli P K Swart andL B Smith Jr ldquoTectonic-hydrothermal brecciation associated with calcite precipitationand permeability destruction in Mississippian carbonate reser-voirs Montana and Wyomingrdquo AAPG Bulletin vol 90 no 11pp 1803ndash1841 2006
[98] M Esteban and C Taberner ldquoSecondary porosity developmentduring late burial in carbonate reservoirs as a result of mixingandor cooling of brinesrdquo Journal of Geochemical Explorationvol 78-79 pp 355ndash359 2003
[99] H G MacHel ldquoInvestigations of burial diagenesis in carbonatehydrocarbon reservoir rocksrdquoGeoscience Canada vol 32 no 3pp 103ndash128 2005
[100] J A Sagan and B S Hart ldquoThree-dimensional seismic-baseddefinition of fault-related porosity development Trenton-BlackRiver interval Saybrook Ohiordquo AAPG Bulletin vol 90 no 11pp 1763ndash1785 2006
[101] F Xing and S Li ldquoGenesis and environment characteristics ofdolomite-hosted quartz and its significance for hydrocarbonexploration in Keping Area Tarim Basin Chinardquo Journal ofEarth Science vol 23 no 4 pp 476ndash489 2012
[102] L Yun and Z Cao ldquoHydrocarbon enrichment pattern andexploration potential of the Ordovician in Shunnan area TarimBasinrdquo Oil and Gas Geology vol 35 no 6 pp 788ndash797 2014
14 Geofluids
[103] Y Li N Ye X Yuan Q Huang B Su and R Zhou ldquoGeologicaland geochemical characteristics of silicified hydrothermal fluidsin Well Shunnan 4 Tarim Basinrdquo Oil and Gas Geology vol 36no 6 pp 934ndash944 2015
[104] L Qi ldquoOil and gas breakthrough in ultra-deep Ordoviciancarbonate formations in Shuntuoguole uplift Tarim BasinrdquoChina Petroleum Exploration vol 21 no 3 pp 38ndash51 2016 (inChinese with English abstract)
[105] H R Qing ldquoAn introduction of petrology and diagenesis ofultra-deep water carbonate reservoirs from the Atlantic Oceanoffshore Brazilrdquo 2017 Oral presentation at Wuxi Institute ofPetroleum Geology of SINOPEC Wuxi China
[106] G J Simandl and S Paradisl ldquoCarbonate-hosted talcrdquo SelectedBritish ColumbiaMineral Deposit Profiles vol 3 pp 35ndash38 1999
[107] Y K Kharaka D R Cole S D Hovorka W D Gunter K GKnauss and BM Freifeld ldquoGas-water-rock interactions in FrioFormation following CO
2injection implications for the storage
of greenhouse gases in sedimentary basinsrdquoGeology vol 34 no7 pp 577ndash580 2006
[108] Z Duan and D Li ldquoCoupled phase and aqueous speciesequilibrium of the H
2OndashCO
2ndashNaClndashCaCO
3system from 0 to
250∘C 1 to 1000 bar with NaCl concentrations up to saturationof haliterdquo Geochimica et Cosmochimica Acta vol 72 no 20 pp5128ndash5145 2008
[109] M R Giles and J DMarshall ldquoConstraints on the developmentof secondary porosity in the subsurface re-evaluation of pro-cessesrdquoMarine and PetroleumGeology vol 3 no 3 pp 243ndash2551986
[110] O S Pokrovsky S V Golubev and J Schott ldquoDissolution kinet-ics of calcite dolomite and magnesite at 25∘C and 0 to 50 atmpCO2rdquo Chemical Geology vol 217 no 3-4 pp 239ndash255 2005
[111] P Cao Z T Karpyn and L Li ldquoThe role of host rock pro-perties in determining potential CO
2migration pathwaysrdquo
International Journal of Greenhouse Gas Control vol 45 pp 18ndash26 2016
[112] M D Fishburn ldquoSignificant results of deep drilling at ElkHills Kern County Californiardquo in Structure Stratigraphy andHydrocarbon Occurrences of the San Joaquin Basin CaliforniaG K Kuespert and S A Reid Eds vol 64 pp 157ndash167 PacificSections Society of Economic Paleontologists and Mineralo-gists and American Association of Petroleum Geologists 1990
[113] E Povoden M Horacek and R Abart ldquoContact metamor-phism of siliceous dolomite and impure limestones from theWerfen formation in the eastern Monzoni contact aureolerdquoMineralogy and Petrology vol 76 no 1-2 pp 99ndash120 2002
[114] S Yuan I-M Chou R C Burruss X Wang and J Li ldquoDispro-portionation and thermochemical sulfate reduction reactions inSndashH2OndashCH
4and SndashD
2OndashCH
4systems from 200 to 340∘C at
elevated pressuresrdquo Geochimica et Cosmochimica Acta vol 118pp 263ndash275 2013
[115] X Wang I-M Chou W Hu and R C Burruss ldquoIn situ obser-vations of liquid-liquid phase separation in aqueous MgSO
4
solutions geological and geochemical implicationsrdquo Geochim-ica et Cosmochimica Acta vol 103 pp 1ndash10 2013
[116] X Wang Y Wan W Hu et al ldquoIn situ observations of liquid-liquid phase separation in aqueous ZnSO
4solutions at tem-
peratures up to 400∘C Implications for Zn2+ndashSO2minus4
[117] X Wang IM Chou W Hu Y Wan and Z Li ldquoPropertiesof lithium under hydrothermal conditions revealed by in situ
Raman spectroscopic characterization of Li2O-SO
3-H2O(D2O)
systems at temperatures up to 420∘Crdquo Chemical Geology vol451 pp 104ndash115 2017
[118] L Shang I-M Chou W Lu R C Burruss and Y ZhangldquoDetermination of diffusion coefficients of hydrogen in fusedsilica between 296 and 523 K by Raman spectroscopy and appli-cation of fused silica capillaries in studying redox reactionsrdquoGeochimica et CosmochimicaActa vol 73 no 18 pp 5435ndash54432009
[119] M Dargent J Dubessy L Truche E F Bazarkina C Nguyen-Trung and P Robert ldquoExperimental study of uranyl(VI) chlo-ride complex formation in acidic LiCl aqueous solutions underhydrothermal conditions (T = 21∘Cndash350∘C Psat) using Ramanspectroscopyrdquo European Journal ofMineralogy vol 25 no 5 pp765ndash775 2013
[120] YWanXWangWHu and I-MChou ldquoRaman spectroscopicobservations of the ion association between Mg2+ and SO2minus
4
in MgSO4-saturated droplets at temperatures of le380∘Crdquo The
Journal of Physical Chemistry A vol 119 no 34 pp 9027ndash90362015
[121] Y Wan X Wang W Hu I M Chou Y Chen and Z Xu ldquoInsitu optical and Raman spectroscopic observations of the effectsof pressure and fluid composition on liquidliquid phase separa-tion in aqueous cadmium sulfate solutions (=400∘C 50MPa)with geological and geochemical implicationsrdquo Geochimica etCosmochimica Acta vol 211 pp 133ndash152 2017
[122] W L Marshall ldquoAmorphous silica solubilitiesmdashI Behavior inaqueous sodium nitrate solutions 25ndash300∘C 0ndash6 molalrdquo Geo-chimica et Cosmochimica Acta vol 44 no 7 pp 907ndash913 1980
[123] C-T A Chen andW LMarshall ldquoAmorphous silica solubilitiesIV Behavior in pure water and aqueous sodium chloridesodium sulfate magnesium chloride and magnesium sulfatesolutions up to 350∘Crdquo Geochimica et Cosmochimica Acta vol46 no 2 pp 279ndash287 1982
[124] B A Fleming and D A Crerar ldquoSilicic acid ionization and cal-culation of silica solubility at elevated temperature and pHapplication to geothermal fluid processing and reinjectionrdquoGeothermics vol 11 no 1 pp 15ndash29 1982
Table 3 The Gibbs free energies of the reaction 3CaMg(CO3)2+ 4SiO
2(aq) + H
2O = Mg
3(Si4O10)(OH)
2+ 3CaCO
3+ 3CO
2at the
temperatures of interest and their corresponding saturation pressures
Temperature (∘C) Δ119866a (kJmol) 119875satb (bar) Temperature (∘C) ΔG (kJmol) 119875sat (bar)
25 7709 0032 100 ndash7083 101450 4663 0124 110 ndash9951 143460 2771 0199 120 ndash12938 198770 0609 0312 130 ndash16032 270380 ndash1778 0474 140 ndash19223 361590 ndash4351 0702 150 ndash22502 4761aΔ119866 refers to the Gibbs free energy of the reaction b119875sat represents the corresponding saturation pressures which are calculated based on the thermodynamicmodel proposed by Zhang and Duan [45]
experiments used to chart out this systemhave been generallyconducted at gt250∘C [4 41ndash44] The reaction path of thephase diagram at low temperatures was mainly establishedthrough thermodynamic calculations implying the need fortalc forming experiments at temperatures below 250∘C
Some geological case studies attribute low talc mineral-ization temperatures (lt200∘C) derived from adjacent talc anddolomite oxygen isotope thermometry to actually reflect iso-topic disequilibrium [36] This study shows that talc depositscan still form at temperatures below 200∘C on geologicaltime scales especially if the product CO
2can be released
(cf reaction (1)) However large-scale talc mineralization ismore likely to form at higher temperatures (eg 250ndash400∘C)Firstly PCO
2controls the lower thermal limit of talc stability
The onset temperature of the transformation increases withincreasing PCO
2 because CO
2is a product of the metamor-
phic reaction (1) and its presence greatly decreases the solu-bility of SiO
2in the fluid [80] CO
2is a common component
in geological fluids and can be either released from magmas(eg [81ndash84]) or generated from the hydrothermal alterationof carbonate (eg [85ndash87]) The oxidation (eg [88]) andhydrothermal maturation of organic matter are also naturalsources of CO
2[89 90]Therefore talcmineralization should
occur at relatively high temperatures in the presence of CO2
Secondly as our results have shown the reaction rate forreaction (1) increases sharply with increasing temperaturefacilitating talc deposits to form at higher temperatures
This study can also contribute to understanding the faultweakening mechanism in the upper crust The elastic strainaccumulation along a fault can be released through a suddenseismic slip (earthquake) or aseismic creep slip [32] A lowerfrictional coefficient for a fault will facilitate stable creepweakening the fault and suppressing the occurrence of strongearthquakes [35]The frictional coefficient of a fault generallydecreases with increasing temperature [35] Therefore faultsare likely to beweakened due to high temperatures in the deepcrust but not in the cool shallow crust The pervasive distri-bution of clay minerals along faults has also been thought toweaken faults [33ndash35 91ndash94] because layered clay mineralsexhibit much lower frictional coefficients than otherminerals[95] For example talc discovered along the SanAndreas faultzone is responsible for helping in aiding slippage along thefault [35 95] As shown here dolomite could react at le200∘Cwith silica-rich fluids traveling along fault planes to form
talc and hence might be an important mechanism of faultweakening in carbonate sequences in the upper crust
42 Implications for Hydrothermal Dolomite Reservoir Re-search Carbonate rock is the main type of hydrocarbonreservoir worldwide hosting over 60 of petroleum reserves[31] Dolomite hydrocarbon reservoirs are important com-prising about half of the carbonate hydrocarbon reser-voirs worldwide [96] Recent research has suggested thathydrothermal alteration can increase the porosity and per-meability of dolomite reservoirs substantially and is animportant factor affecting the development and distributionof dolomite reservoirs [24 25 97ndash101] The Tarim basin isone of the most important petroliferous basins in China andcontains a lower Palaeozoic carbonate series which is alsoan important hydrocarbon reservoir Recent exploration hasshown that silica-rich hydrothermal fluids have infiltratedthese carbonate series improving the physical properties ofthe reservoirs considerably (eg the Shunnan area of theTarim Basin [102 103]) It has been proposed that silica-richhydrothermal fluids were transported through extensionalfaults from the deep strata to the shallow carbonate sequencewhere they migrated laterally through porous and permeablecarbonate formations (sim6670m in the Shunnan area [104])Hydrothermal fluids originating in deep basins are generallyhot Microthermometric measurements have indicated thatthe silica-rich hydrothermal fluids in the Tarim basin reachover 200∘C [101 103] Given that the lower part of the lowerPalaeozoic sequence is mainly composed of dolomite silica-rich hydrothermal fluids could react with the dolomite toform talc and thus change the physical properties of the reser-voir Recently petrologic and diagenetic research haverevealed pervasive silicification in Early Cretaceous ultra-deep water carbonate reservoirs in the Atlantic Ocean off-shore from Brazil [105] The presence of talc calcite quartzand dolomite on the thin-section scale may indicate that thedolomite was strongly corroded by a silica-rich hydrothermalfluid
Alteration of dolomite to talcwill alsomodify the porosityand permeability of carbonate hydrocarbon reservoirs [29ndash31] The silica required for the mineral alteration can be pro-vided by either silica-rich hydrothermal fluids or silica (egquartz chert and opal) within the carbonate reservoirs [106]If SiO
2derives from quartzchert in the dolomite sequences
Geofluids 9
the hydrothermal alteration would increase the porosity ofthe dolomite reservoirs McKinley et al [29] reported thatthe total volume of minerals within a dolomite reservoir canbe reduced by 13 to 17 through the reaction betweendolomite and quartz in reaction (1) In addition the reactionbetween dolomite and silica-rich hydrothermal fluids can actas an important source of CO
2 in hydrocarbon reservoirsThepresence of CO2 can lower the pH of the formation waterand thus promote the dissolution of carbonate minerals [60107 108] increasing the porosity of the reservoirs [109ndash111]However the pore throats may be blocked by the formationof talc or other clay minerals [29 112] Therefore moredetailed factors should be considered in order to unequi-vocally evaluate the effects of silica-rich hydrothermal fluidsin dolomite reservoirs
Although talc can form from the interaction betweendolomite and silica-rich fluids at low temperatures it isseldom observed in hydrocarbon reservoirs [29 31] for thefollowing two reasons (1)A large amount of CO
2can be pro-
duced by the maturation of organic matter and the reactionbetween carbonate minerals and organic acid [98 101] Thepresence of CO
2decreases the lower thermal stability field
of talc [113] (2)The reaction path is dependent on the com-position of the hydrothermal fluid For example K+ andAl3+ are also important components of geological fluidsMontmorillonite instead of talc is more likely to form inthe presence of only a small quantity of Al3+ [41] and theformation of talc can also be inhibited by K+ [29]
43 Implications for High PndashT Experiment Using Fused SilicaCapillary Tubes as Reactors FSCCs are used to constructsynthetic fluid inclusions containing organic and inorganiccomponents [46] They offer advantages such as being inertto many components especially acids and S allowing forthe convenient synthesis of fluid inclusions and facilitatingin situ optical and Raman spectroscopic observations (eg[57 114ndash117]) Fused silica tubes can tolerate relatively hightemperatures up to 600∘C and pressures up to 300MPa As aresult FSCCs are used in many research fields For examplein addition to construction of synthetic fluid inclusions[46 53 118] FSCCs were used in studying the propertiesof hydrothermal fluids as optical and Raman spectroscopiccells [115ndash117 119ndash121] FSCCs were also used as reactorsin investigating the mechanism of thermochemical sulfatereduction [114] and the decomposition of organic matter[57]
However SiO2 in the FSCC acted as a reagent in thisstudy and was partially dissolved as indicated by the pitson the inner surface of the tube (Figures 8(a)ndash8(d)) Thedissolution of silica from FSCCs containing alkali sulfatesolutions was also observed after quenching from ge350∘C(Figures 8(e) and 8(f)) The severe dissolution of fused silicacan be ascribed to three factors (1) Amorphous silica ismore soluble than quartz especially at high temperaturesIn neutral solutions its solubility increases sharply withtemperature from 100 ppm at 20∘C to 1500 ppm at 310∘C[74 122 123] (2) Under basic conditions the solubility ofamorphous silica is greatly enhanced by the ionization ofsilicic acid (H
4SiO4+ OHminus rarr H
3SiO4
minus + H2O [124]) (3)
SiO2may act as a reagent as it did in this experiment The
presence of dissolution pits will weaken the mechanicalstrength of the silica tube In addition the presence ofdissolved silica can make the system more complicated thanexpected Therefore the solubility and reactivity of silicaunder hydrothermal conditions should be evaluated beforeFSCCs are used as reactors
5 Conclusion
The reactions in the CaMg(CO3)2ndashSiO2ndashH2O system atlow temperatures were investigated using fused silica tubesas reactors Results showed that dolomite reacted with asilica-rich fluid to form talc calcite and CO2 at le200
∘Cand low PCO2 The reaction rate increased with increasingtemperature and decreased with rising PCO2Therefore hightemperature and the presence of a conduit to release CO2 willpromote the formation of talcThis experiment has importantgeological and geochemical implications(1)Theresults confirmed themechanism of talcminerali-
zation in Mg-carbonate hosted talc deposits Dolomitereacted with silica-rich hydrothermal fluids to form talccalcite and CO
2 Talc could form at le200∘C whereas pre-
vious hydrothermal experiments examining the CaOndashMgOndashSiO2ndashCO2ndashH2O system were mainly conducted at gt250∘C
However considering the effect of temperature on thereaction rate and other geological conditions massive talcdeposits are still more likely to form at higher temperaturesThe formation of talc along a fault in a Mg-carbonateformation will also weaken the fault thus preventing strongearthquakes(2) Talc in carbonate reservoirs can indicate the activity
of silica-rich hydrothermal fluids Fluid-aided alteration ofdolomite can change the physical properties of dolomitereservoirs substantially The reaction between dolomite andquartz within the carbonate can decrease the total volume ofminerals by 13ndash17 The generation of CO2 can promotethe dissolution of carbonate minerals elsewhere under theappropriate conditions increasing the porosity and perme-ability of carbonate reservoirs However talc minerals mayblock pore throats in the reservoirs Therefore additionalfactors need to be considered when evaluating the effectsof CaMg(CO
3)2ndashSiO2ndashH2O interactions on the physical
properties of carbonate reservoirs(3) The solubility and reactivity of silica should be con-
sidered when using fused silica tubes as reactors in highPndashT experiments The dissolution of silica will increase thecomplexity of the system andweaken themechanical strengthof the tube
Conflicts of Interest
The authors declare that they have no conflicts of interest
Acknowledgments
The dolomite sample was provided by Mr Chunhua ShiMisses Yang Qu Wanlu Gao and Ye Qiu helped the authorsa lot during the micro-XRD analysis and HPOC experiment
10 Geofluids
Outer surfaceInner surface
(a) (b)In
ner s
urfa
ce
(c) (d)
Inner surface
(e) (f)
Figure 8 SEM images of the inner surface of the silica tube (a) Smooth inner surface before the reaction (b) magnification of the squarearea shown in (a) (c) dissolution pits on the inner surface after heating at 200∘C for sim60 days (d) magnification of (c) severe erosion of thesilica on the inner surface of FSCCs containing (e) 10m Na
2SO4and (f) 10m Li
2SO4after heating at 350∘C for 1 h
Dr Rui Wang and Miss Siyu Hu are also thanked for theirhelp in the thermodynamic calculations of the reactionsThis work was financially supported by the National NaturalScience Foundation of China (Grant nos 41230312 and41573054) I-Ming Chou is thankful for the support of theKnowledge Innovation Program (SIDSSE-201302) and theHadal-trench Research Program (XDB06060100) of ChineseAcademy of Sciences
References
[1] L D Meinert ldquoSkarns and skarn depositsrdquo Geoscience Canadavol 19 no 4 pp 145ndash162 1992
[2] L D Meinert G M Dipple and S Nicolescu ldquoWorld skarndepositsrdquo Economic Geology 100th Anniversary Volume pp299ndash336 2005
[3] Y Yao J Chen J Lu R Wang and R Zhang ldquoGeology andgenesis of the Hehuaping magnesian skarn-type cassiterite-sulfide deposit Hunan Province Southern ChinardquoOre GeologyReviews vol 58 no C pp 163ndash184 2014
[4] T M Gordon and H J Greenwood ldquoThe reaction dolomite+ quartz + water = talc + calcite + carbon dioxiderdquo AmericanJournal of Science vol 268 pp 225ndash242 1970
[5] M B Holness ldquoFluid flow paths and mechanisms of fluidinfiltration in carbonates during contact metamorphism TheBeinn an Dubhaich aureole Skyerdquo Journal of MetamorphicGeology vol 15 no 1 pp 59ndash70 1997
Geofluids 11
[6] W Heinrich S S Churakov andM Gottschalk ldquoMineral-fluidequilibria in the system CaOndashMgOndashSiO
2ndashH2OndashCO
2ndashNaCl
and the record of reactive fluid flow in contact metamorphicaureolesrdquo Contributions to Mineralogy and Petrology vol 148no 2 pp 131ndash149 2004
[7] M Wesołowski ldquoThermal decomposition of talc a reviewrdquoThermochimica Acta vol 78 no 1-3 pp 395ndash421 1984
[8] L A Perez-Maqueda A Duran and J L Perez-RodrıguezldquoPreparation of submicron talc particles by sonicationrdquoAppliedClay Science vol 28 no 1-4 pp 245ndash255 2005
[9] R L Johnson ldquoTalcrdquoAmerican Ceramic Society Bulletin vol 71pp 818ndash820 1992
[10] R L Johnson and R L Virta ldquoTalcrdquo American Ceramic SocietyBulletin vol 79 pp 79ndash81 2000
[11] M Z Abzalov ldquoChrome-spinels in gabbro-wehrlite intrusionsof the Pechenga area Kola Peninsula Russia emphasis onalteration featuresrdquo Lithos vol 43 no 3 pp 109ndash134 1998
[12] M F El-Sharkawy ldquoTalc mineralization of ultramafic affinity inthe Eastern Desert of Egyptrdquo Mineralium Deposita vol 35 no4 pp 346ndash363 2000
[13] M Franceschelli G Carcangiu A M Caredda G CrucianiI Memmi and M Zucca ldquoTransformation of cumulate maficrocks to granulite and re-equilibration in amphibolite andgreenschist facies in NE Sardinia Italyrdquo Lithos vol 63 no 1-2pp 1ndash18 2002
[14] S G Tesalina P Nimis T Auge and V V Zaykov ldquoOriginof chromite in mafic-ultramafic-hosted hydrothermal massivesulfides from the Main Uralian Fault South Urals RussiardquoLithos vol 70 no 1-2 pp 39ndash59 2003
[15] D M Evans ldquoMetamorphic modifications of the Muremeramafic-ultramafic intrusions eastern Burundi and their effecton chromite compositionsrdquo Journal of African Earth Sciencesvol 101 pp 19ndash34 2015
[16] T Yamanaka K Maeto H Akashi et al ldquoShallow submarinehydrothermal activity with significant contribution of mag-matic water producing talc chimneys in the Wakamiko CraterofKagoshimaBay southernKyushu Japanrdquo Journal of Volcanol-ogy and Geothermal Research vol 258 pp 74ndash84 2013
[17] B Moine J P Fortune P Moreau and F Viguier ldquoComparativemineralogy geochemistry and conditions of formation of twometasomatic talc and chlorite deposits Trimouns PyreneesFrance and Rabenwald eastern Alps Austriardquo Economic Geol-ogy vol 84 no 5 pp 1398ndash1416 1989
[18] W Prochaska ldquoGeochemistry and genesis of Austrian talcdepositsrdquo Applied Geochemistry vol 4 no 5 pp 511ndash525 1989
[19] P de Parseval S Jiang F Fontan R Wang F Martin and JFreeet ldquoGeology and ore genesis of the Trimouns talc-chloriteore deposit Pyrenees Francerdquo Acta Petrologica Sinica vol 20no 4 pp 877ndash886 2004
[20] A C Gondim and S Jiang ldquoGeologic characteristics and gene-ticmodels for the talc deposits in Parana andBahia BrazilrdquoActaPetrologica Sinica vol 20 no 4 pp 829ndash836 2004
[21] P Boulvais P de Parseval A DrsquoHulst and P Paris ldquoCarbonatealteration associated with talc-chlorite mineralization in theeastern Pyrenees with emphasis on the St Barthelemy MassifrdquoMineralogy and Petrology vol 88 no 3-4 pp 499ndash526 2006
[22] G R Davies and L B Smith Jr ldquoStructurally controlled hydro-thermal dolomite reservoir facies an overviewrdquoAAPG Bulletinvol 90 no 11 pp 1641ndash1690 2006
[23] J Lonnee and H G Machel ldquoPervasive dolomitization withsubsequent hydrothermal alteration in theClarke Lake gas field
Middle Devonian Slave Point Formation British ColumbiaCanadardquo AAPG Bulletin vol 90 no 11 pp 1739ndash1761 2006
[24] J A Luczaj ldquoEvidence against the Dorag (mixing-zone) modelfor dolomitization along theWisconsin arch - A case for hydro-thermal diagenesisrdquo AAPG Bulletin vol 90 no 11 pp 1719ndash1738 2006
[25] L B Smith Jr ldquoOrigin and reservoir characteristics of UpperOrdovician Trenton-Black River hydrothermal dolomite reser-voirs in New YorkrdquoAAPG Bulletin vol 90 no 11 pp 1691ndash17182006
[26] J Parnell ldquoDevonianMagadi-type cherts in theOrcadian BasinScotlandrdquo Journal of Sedimentary Petrology vol 56 no 4 pp495ndash500 1986
[27] J M Garcıa-Ruiz ldquoCarbonate precipitation into alkaline silica-rich environmentsrdquo Geology vol 26 no 9 pp 843ndash846 1998
[28] J Zhang W Hu Y Qian et al ldquoFormation of saddle dolomitesin Upper Cambrian carbonates western Tarim Basin (north-west China) implications for fault-related fluid flowrdquo Marineand Petroleum Geology vol 26 no 8 pp 1428ndash1440 2009
[29] J M McKinley R H Worden and A H Ruffell ldquoContactdiagenesis the effect of an intrusion on reservoir quality in thetriassic sherwood sandstone group Northern Irelandrdquo Journalof Sedimentary Research vol 71 no 3 pp 484ndash495 2001
[30] S Dong D Chen H Qing et al ldquoHydrothermal alteration ofdolostones in the Lower Ordovician Tarim Basin NW Chinamultiple constraints from petrology isotope geochemistry andfluid inclusion microthermometryrdquo Marine and PetroleumGeology vol 46 pp 270ndash286 2013
[31] V Madrucci C W D D Anjos R A Spadini D B Alvesand S M C Anjos ldquoAuthigenic magnesian clays in carbonatereservoirs in Brazilrdquo in Proceedings of the 15th International ClayConference Rio De Janeiro Brazil 2013
[32] C H Scholz ldquoEarthquakes and friction lawsrdquo Nature vol 391no 6662 pp 37ndash42 1998
[33] A M Schleicher B A Van Der Pluijm J G Solum andL N Warr ldquoOrigin and significance of clay-coated fracturesin mudrock fragments of the SAFOD borehole (ParkfieldCalifornia)rdquoGeophysical Research Letters vol 33 no 16 ArticleID L16313 2006
[34] A M Schleicher B A van der Pluijm and L N Warr ldquoNano-coatings of clay and creep of the San Andreas fault at ParkfieldCaliforniardquo Geology vol 38 no 7 pp 667ndash670 2010
[35] C Collettini C Viti S A F Smith and R E HoldsworthldquoDevelopment of interconnected talc networks and weakeningof continental low-angle normal faultsrdquo Geology vol 37 no 6pp 567ndash570 2009
[36] F Tornos and B F Spiro ldquoThe geology and isotope geochem-istry of the talc deposits of Puebla de Lillo (Cantabrian zonenorthern Spain)rdquo Economic Geology vol 95 no 6 pp 1277ndash1296 2000
[37] L Hecht R Freiberger H A Gilg G Grundmann and Y AKostitsyn ldquoRare earth element and isotope (C O Sr) charac-teristics of hydrothermal carbonates genetic implications fordolomite-hosted talc mineralization at Gopfersgrun (Fichtelge-birge Germany)rdquo Chemical Geology vol 155 no 1-2 pp 115ndash130 1999
[38] R Sharma P Joshi and P D Pant ldquoThe role of fluids inthe formation of talc deposits of Rema area Kumaun LesserHimalayardquo Journal of the Geological Society of India vol 73 no2 pp 237ndash248 2009
12 Geofluids
[39] P De Parseval B Moine J P Fortune and J Ferret ldquoFluid-mineral interactions at the origin of the Trimouns talc andchlorite deposit (Pyrenees France)rdquo in Current Research inGeology Applied to Ore Deposits P Fenoll Hach-Ali J Torrez-Ruiz and F Gervilla Eds pp 205ndash209 University of GranadaGranada Granada Spain 1993
[40] M C Boiron P Boulvais M Cathelineau D Banks N Cal-vayrac and G Hubert ldquoFluid circulation at the origin of thetrimouns talc deposit (Pyrenees France)rdquo in Proceedings of the18th Meeting of European Current Research on Fluid InclusionsSiena Italy 2005
[41] P Bayliss andA A Levhinson ldquoLow temperature hydrothermalsynthesis from dolomite or calcite quartz and kaoliniterdquo Claysand Clay Minerals vol 19 no 2 pp 109ndash114 1971
[42] G Skippen ldquoAn experimental model for low pressure meta-morphism of siliceous dolomitic marblerdquo American Journal ofScience vol 274 no 5 pp 487ndash509 1974
[43] J Slaughter D M Kerrick and V J Wall ldquoExperimen-tal and thermodynamic study of equilibria in the systemCaOndashMgOndashSiO
2ndashH2OndashCO
2rdquoAmerican Journal of Science vol
275 pp 143ndash162 1975[44] R G Eggert and D M Kerrick ldquoMetamorphic equilibria in the
siliceous dolomite system 6 kbar experimental data and geo-logic implicationsrdquo Geochimica et Cosmochimica Acta vol 45no 7 pp 1039ndash1049 1981
[45] Z Zhang and Z Duan ldquoPrediction of the PVT properties ofwater over wide range of temperatures and pressures frommolecular dynamics simulationrdquo Physics of the Earth andPlanetary Interiors vol 149 no 3-4 pp 335ndash354 2005
[46] I-M Chou Y Song and R C Burruss ldquoA newmethod for syn-thesizing fluid inclusions in fused silica capillaries containingorganic and inorganic materialrdquo Geochimica et CosmochimicaActa vol 72 no 21 pp 5217ndash5231 2008
[47] I-M Chou R C Burruss and W J Lu ldquoA new optical cellfor spectroscopic studies of geologic fluids at pressures up to100MPardquo in Advances in High-Pressure Technology for Geo-physical Applications J Chen YWang T S Duffy G Shen andL F Dobrzhinetakaya Eds pp 475ndash485 Elsevier AmsterdamNetherlands 2005
[48] K M Rosso and R J Bodnar ldquoMicrothermometric and Ramanspectroscopic detection limits of CO
2in fluid inclusions and the
Raman spectroscopic characterization of CO2rdquo Geochimica et
Cosmochimica Acta vol 59 no 19 pp 3961ndash3975 1995[49] H M Lamadrid Geochemistry of fluid-rock processes [Doctoral
dissertation] Virginia Polytechnic Institute and State Univer-sity Blacksburg VA USA 2016
[50] J H Parker D W Feldman and M Ashkin ldquoRaman scatteringby silicon and germaniumrdquo Physical Review vol 155 no 3 pp712ndash714 1967
[51] Y V Shvarov ldquoAlgorithmization of the numeric equilibriummodeling of dynamic geochemical processesrdquo GeochemistryInternational vol 37 no 6 pp 571ndash576 1999
[52] R B Wright and C H Wang ldquoDensity effect on the Fermiresonance in gaseous CO
2by Raman scatteringrdquoThe Journal of
Chemical Physics vol 58 no 7 pp 2893ndash2895 1973[53] XWang I-M ChouWHu R C Burruss Q Sun and Y Song
ldquoRaman spectroscopic measurements of CO2density experi-
mental calibration with high-pressure optical cell (HPOC) andfused silica capillary capsule (FSCC) with application to fluidinclusion observationsrdquo Geochimica et Cosmochimica Acta vol75 no 14 pp 4080ndash4093 2011
[54] H R Gordon and T K McCubbin Jr ldquoThe 28-micron bandsof CO
2rdquo Journal of Molecular Spectroscopy vol 19 no 1ndash4 pp
137ndash154 1966[55] T Azbej M J Severs B G Rusk and R J Bodnar ldquoIn situ
quantitative analysis of individual H2O-CO
2fluid inclusions by
laser Raman spectroscopyrdquo Chemical Geology vol 237 no 3-4pp 255ndash263 2007
[56] Y Song I M Chou W Hu B Robert and W Lu ldquoCO2
density-raman shift relation derived from synthetic inclusionsin fused silica capillaries and its applicationrdquo Acta GeologicaSinica (English Edition) vol 83 pp 932ndash938 2009
[57] Z Pan I-M Chou and R C Burruss ldquoHydrolysis of polycar-bonate in sub-critical water in fused silica capillary reactor within situ Raman spectroscopyrdquo Green Chemistry vol 11 no 8 pp1105ndash1107 2009
[58] M L Frezzotti F Tecce and A Casagli ldquoRaman spectroscopyfor fluid inclusion analysisrdquo Journal of Geochemical Explorationvol 112 pp 1ndash20 2012
[59] E L Shock and H C Helgeson ldquoCalculation of the thermo-dynamic and transport properties of aqueous species at highpressures and temperatures correlation algorithms for ionicspecies and equation of state predictions to 5 kb and 1000∘CrdquoGeochimica et Cosmochimica Acta vol 52 no 8 pp 2009ndash20361988
[60] O S Pokrovsky SVGolubev J Schott andACastillo ldquoCalcitedolomite and magnesite dissolution kinetics in aqueous solu-tions at acid to circumneutral pH 25 to 150∘C and 1 to 55 atmpCO2 New constraints on CO
2sequestration in sedimentary
basinsrdquo Chemical Geology vol 265 no 1-2 pp 20ndash32 2009[61] YGarrabos R Tufeu B LeNeindre G Zalczer andD Beysens
ldquoRayleigh andRaman scattering near the critical point of carbondioxiderdquo The Journal of Chemical Physics vol 72 no 8 pp4637ndash4651 1979
[62] J H Nicola J F Scott R M Couto andMM Correa ldquoRamanspectra of dolomite [CaMg(CO
3)2]rdquo Physical Review B vol 14
no 10 pp 4676ndash4678 1976[63] S Gunasekaran G Anbalagan and S Pandi ldquoRaman and
infrared spectra of carbonates of calcite structurerdquo Journal ofRaman Spectroscopy vol 37 no 9 pp 892ndash899 2006
[64] G J Rosasco and J J Blaha ldquoRaman microprobe spectra andvibrationalmode assignments of talcrdquoApplied Spectroscopy vol34 no 2 pp 140ndash144 1980
[65] V Trommsdorff and B W Evans ldquoAntigorite-ophicarbo-nates phase relations in a portion of the system CaOndashMgOndashSiO2ndashH2OndashCO
2rdquo Contributions to Mineralogy and Petrology
vol 60 no 1 pp 39ndash56 1977[66] V Trommsdorff and J A D Connolly ldquoConstraints on phase
diagram topology for the systemCaOndashMgOndashSiO2ndashCO2ndashH2Ordquo
Contributions to Mineralogy and Petrology vol 104 no 1 pp 1ndash7 1990
[67] B S Van Gosen H A Lowers S J Sutley and C A GentldquoUsing the geologic setting of talc deposits as an indicator ofamphibole asbestos contentrdquo Environmental Geology vol 45no 7 pp 920ndash939 2004
[68] W Johannes ldquoAn experimental investigation of the systemMgO-SiO
2-H2O-CO
2rdquo American Journal of Science vol 267
no 9 pp 1083ndash1104 1969[69] E S Schandl and M P Gorton ldquoHydrothermal alteration and
CO2metasomatism (natural carbon sequestration) of komati-
ites in the south-western Abitibi greenstone beltrdquo CanadianMineralogist vol 50 no 1 pp 129ndash146 2012
Geofluids 13
[70] B W Evans and S Guggenheim ldquoTalc phyrophyllite andrelated mineralsrdquo in Reviews in Mineralogy S W Bailey Edvol 19 pp 225ndash294 1988
[71] B Velde ldquoExperimental pseudomorphism of diopside by talcand serpentine in (Ni Mg)Cl
2aqueous solutionsrdquo Geochimica
et Cosmochimica Acta vol 52 no 2 pp 415ndash424 1988[72] A E Williams-Jones C Normand H Clark Vali Jr R F
Martin A Dufresne and Nayebzadeh A ldquoControls of amphi-bole formation in chrysotile from the Jeffrey Mine AsbestosQuebecrdquo inTheHealth Effects Effects of Chrysotile Asbestos R PNolan AM LangerM RossWicks F J andMartin F R Edsvol 5 pp 89ndash104 The Mineralogical Association of CanadaQuebec Quebec Canada 2001
[73] B W Evans ldquoThe serpentinite multisystem revisited chrysotileis metastablerdquo International Geology Review vol 46 no 6 pp479ndash506 2004
[74] I Gunnarsson and S Arnorsson ldquoAmorphous silica solubilityand the thermodynamic properties of H
4SiO∘4in the range of
0∘ to 350∘C at Psatrdquo Geochimica et Cosmochimica Acta vol 64no 13 pp 2295ndash2307 2000
[75] M W Bodine Jr ldquoTrioctahedral clay mineral assemblages inPaleozoic marine evaporite rocksrdquo in Proceedings of the Pre-sented in the Sixth International Symposium on Salt vol 1 pp267ndash284 Toronto Canada 1983
[76] W Schreyer and K Abraham ldquoThree-stage metamorphic his-tory of a whiteschist from Sar e Sang Afghanistan as part ofa former evaporite depositrdquo Contributions to Mineralogy andPetrology vol 59 no 2 pp 111ndash130 1976
[77] T Angerer and S G Hagemann ldquoThe BIF-hosted high-gradeiron ore deposits in the archean koolyanobbing greenstonebelt Western Australia structural control on synorogenic-and weathering-related magnetite- hematite- and goethite-rich iron orerdquo Economic Geology vol 105 no 5 pp 917ndash9452010
[78] P Duuring and S Hagemann ldquoLeaching of silica bands andconcentration of magnetite in Archean BIF by hypogene fluidsBeebyn Fe ore deposit Yilgarn Craton Western AustraliardquoMineralium Deposita vol 48 no 3 pp 341ndash370 2013
[79] D Shin and I Lee ldquoFluid inclusions and their stable isotopegeochemistry of the carbonate-hosted talc deposits near theCretaceous Muamsa Granite South Koreardquo Geochemical Jour-nal vol 40 no 1 pp 69ndash85 2006
[80] P G Novgorodov ldquoSolubility of quartz in anH2OndashCO
2mixture
at 700 degrees C and pressures of 3 and 5 kbarsrdquoGeokhimiya pp1484ndash1489 1975
[81] T M Gerlach ldquoChemical characteristics of the volcanic gasesfrom Nyiragongo lava lake and the generation of CH
4-rich
fluid inclusions in alkaline rocksrdquo Journal of Volcanology ampGeothermal Research vol 8 no 2-4 pp 177ndash189 1980
[82] J V Walther and P M Orville ldquoVolatile production and trans-port in regional metamorphismrdquo Contributions to Mineralogyand Petrology vol 79 no 3 pp 252ndash257 1982
[83] W F Giggenbach ldquoThe origin and evolution of fluids inmagmatic-hydrothermal systemsrdquo in Geochemistry of Hydro-thermalOreDeposits H L Barnes Ed pp 737ndash796WileyNewYork NY USA 3 edition 1997
[84] J B Lowenstern ldquoCarbon dioxide in magmas and implicationsfor hydrothermal systemsrdquoMineralium Deposita vol 36 no 6pp 490ndash502 2001
[85] R Kerrich and W S Fyfe ldquoThe gold-carbonate associationsource of CO
2 and CO
2fixation reactions in Archaean lode
depositsrdquo Chemical Geology vol 33 no 1ndash4 pp 265ndash294 1981
[86] P I Nabelek ldquoCalc-silicate reactions and bedding-controlledisotopic exchange in the Notch Peak aureole Utah implicationsfor differential fluid fluxes with metamorphic graderdquo Journal ofMetamorphic Geology vol 20 no 4 pp 429ndash440 2002
[87] P I Nabelek ldquoFluid evolution and kinetics of metamorphicreactions in calc-silicate contact aureoles - From H
2O to CO
2
and backrdquo Geology vol 35 no 10 pp 927ndash930 2007[88] H G Machel ldquoBacterial and thermochemical sulfate reduction
in diagenetic settings - old and new insightsrdquo SedimentaryGeology vol 140 no 1-2 pp 143ndash175 2001
[89] L Stalker P Farrimond and S R Larter ldquoWater as an oxygensource for the production of oxygenated compounds (includingCO2precursors) during kerogen maturationrdquo Organic Geo-
chemistry vol 22 no 3-5 pp 477ndashIN4 1994[90] Z K Shipton J P Evans D Kirschner P T Kolesar A P
Williams and J Heath ldquoAnalysis of CO2leakage through lsquolow-
permeabilityrsquo faults from natural reservoirs in the ColoradoPlateau east-central Utahrdquo Geological Society Special Publica-tion vol 233 pp 43ndash58 2004
[91] J Byerlee ldquoFriction overpressure and fault normal compres-sionrdquo Geophysical Research Letters vol 17 no 12 pp 2109ndash21121990
[92] C Morrow B Radney and J Byerlee ldquoChapter 3 frictionalstrength and the effective pressure law of montmorillonite andlllite claysrdquo International Geophysics vol 51 no C pp 69ndash881992
[93] C A Morrow D E Moore and D A Lockner ldquoThe effectof mineral bond strength and adsorbed water on fault gougefrictional strengthrdquo Geophysical Research Letters vol 27 no 6pp 815ndash818 2000
[94] D A Lockner C Morrow D Moore and S Hickman ldquoLowstrength of deep San Andreas fault gouge from SAFOD corerdquoNature vol 472 no 7341 pp 82ndash86 2011
[95] D EMoore andM J Rymer ldquoTalc-bearing serpentinite and thecreeping section of the San Andreas faultrdquo Nature vol 448 no7155 pp 795ndash797 2007
[96] DH Zenger ldquoDiscussion lsquoOn the formation and occurrence ofsaddle dolomitersquordquo Journal of Sedimentary Petrology vol 51 no4 pp 1350ndash1352 1981
[97] DAKatzG P Eberli P K Swart andL B Smith Jr ldquoTectonic-hydrothermal brecciation associated with calcite precipitationand permeability destruction in Mississippian carbonate reser-voirs Montana and Wyomingrdquo AAPG Bulletin vol 90 no 11pp 1803ndash1841 2006
[98] M Esteban and C Taberner ldquoSecondary porosity developmentduring late burial in carbonate reservoirs as a result of mixingandor cooling of brinesrdquo Journal of Geochemical Explorationvol 78-79 pp 355ndash359 2003
[99] H G MacHel ldquoInvestigations of burial diagenesis in carbonatehydrocarbon reservoir rocksrdquoGeoscience Canada vol 32 no 3pp 103ndash128 2005
[100] J A Sagan and B S Hart ldquoThree-dimensional seismic-baseddefinition of fault-related porosity development Trenton-BlackRiver interval Saybrook Ohiordquo AAPG Bulletin vol 90 no 11pp 1763ndash1785 2006
[101] F Xing and S Li ldquoGenesis and environment characteristics ofdolomite-hosted quartz and its significance for hydrocarbonexploration in Keping Area Tarim Basin Chinardquo Journal ofEarth Science vol 23 no 4 pp 476ndash489 2012
[102] L Yun and Z Cao ldquoHydrocarbon enrichment pattern andexploration potential of the Ordovician in Shunnan area TarimBasinrdquo Oil and Gas Geology vol 35 no 6 pp 788ndash797 2014
14 Geofluids
[103] Y Li N Ye X Yuan Q Huang B Su and R Zhou ldquoGeologicaland geochemical characteristics of silicified hydrothermal fluidsin Well Shunnan 4 Tarim Basinrdquo Oil and Gas Geology vol 36no 6 pp 934ndash944 2015
[104] L Qi ldquoOil and gas breakthrough in ultra-deep Ordoviciancarbonate formations in Shuntuoguole uplift Tarim BasinrdquoChina Petroleum Exploration vol 21 no 3 pp 38ndash51 2016 (inChinese with English abstract)
[105] H R Qing ldquoAn introduction of petrology and diagenesis ofultra-deep water carbonate reservoirs from the Atlantic Oceanoffshore Brazilrdquo 2017 Oral presentation at Wuxi Institute ofPetroleum Geology of SINOPEC Wuxi China
[106] G J Simandl and S Paradisl ldquoCarbonate-hosted talcrdquo SelectedBritish ColumbiaMineral Deposit Profiles vol 3 pp 35ndash38 1999
[107] Y K Kharaka D R Cole S D Hovorka W D Gunter K GKnauss and BM Freifeld ldquoGas-water-rock interactions in FrioFormation following CO
2injection implications for the storage
of greenhouse gases in sedimentary basinsrdquoGeology vol 34 no7 pp 577ndash580 2006
[108] Z Duan and D Li ldquoCoupled phase and aqueous speciesequilibrium of the H
2OndashCO
2ndashNaClndashCaCO
3system from 0 to
250∘C 1 to 1000 bar with NaCl concentrations up to saturationof haliterdquo Geochimica et Cosmochimica Acta vol 72 no 20 pp5128ndash5145 2008
[109] M R Giles and J DMarshall ldquoConstraints on the developmentof secondary porosity in the subsurface re-evaluation of pro-cessesrdquoMarine and PetroleumGeology vol 3 no 3 pp 243ndash2551986
[110] O S Pokrovsky S V Golubev and J Schott ldquoDissolution kinet-ics of calcite dolomite and magnesite at 25∘C and 0 to 50 atmpCO2rdquo Chemical Geology vol 217 no 3-4 pp 239ndash255 2005
[111] P Cao Z T Karpyn and L Li ldquoThe role of host rock pro-perties in determining potential CO
2migration pathwaysrdquo
International Journal of Greenhouse Gas Control vol 45 pp 18ndash26 2016
[112] M D Fishburn ldquoSignificant results of deep drilling at ElkHills Kern County Californiardquo in Structure Stratigraphy andHydrocarbon Occurrences of the San Joaquin Basin CaliforniaG K Kuespert and S A Reid Eds vol 64 pp 157ndash167 PacificSections Society of Economic Paleontologists and Mineralo-gists and American Association of Petroleum Geologists 1990
[113] E Povoden M Horacek and R Abart ldquoContact metamor-phism of siliceous dolomite and impure limestones from theWerfen formation in the eastern Monzoni contact aureolerdquoMineralogy and Petrology vol 76 no 1-2 pp 99ndash120 2002
[114] S Yuan I-M Chou R C Burruss X Wang and J Li ldquoDispro-portionation and thermochemical sulfate reduction reactions inSndashH2OndashCH
4and SndashD
2OndashCH
4systems from 200 to 340∘C at
elevated pressuresrdquo Geochimica et Cosmochimica Acta vol 118pp 263ndash275 2013
[115] X Wang I-M Chou W Hu and R C Burruss ldquoIn situ obser-vations of liquid-liquid phase separation in aqueous MgSO
4
solutions geological and geochemical implicationsrdquo Geochim-ica et Cosmochimica Acta vol 103 pp 1ndash10 2013
[116] X Wang Y Wan W Hu et al ldquoIn situ observations of liquid-liquid phase separation in aqueous ZnSO
4solutions at tem-
peratures up to 400∘C Implications for Zn2+ndashSO2minus4
[117] X Wang IM Chou W Hu Y Wan and Z Li ldquoPropertiesof lithium under hydrothermal conditions revealed by in situ
Raman spectroscopic characterization of Li2O-SO
3-H2O(D2O)
systems at temperatures up to 420∘Crdquo Chemical Geology vol451 pp 104ndash115 2017
[118] L Shang I-M Chou W Lu R C Burruss and Y ZhangldquoDetermination of diffusion coefficients of hydrogen in fusedsilica between 296 and 523 K by Raman spectroscopy and appli-cation of fused silica capillaries in studying redox reactionsrdquoGeochimica et CosmochimicaActa vol 73 no 18 pp 5435ndash54432009
[119] M Dargent J Dubessy L Truche E F Bazarkina C Nguyen-Trung and P Robert ldquoExperimental study of uranyl(VI) chlo-ride complex formation in acidic LiCl aqueous solutions underhydrothermal conditions (T = 21∘Cndash350∘C Psat) using Ramanspectroscopyrdquo European Journal ofMineralogy vol 25 no 5 pp765ndash775 2013
[120] YWanXWangWHu and I-MChou ldquoRaman spectroscopicobservations of the ion association between Mg2+ and SO2minus
4
in MgSO4-saturated droplets at temperatures of le380∘Crdquo The
Journal of Physical Chemistry A vol 119 no 34 pp 9027ndash90362015
[121] Y Wan X Wang W Hu I M Chou Y Chen and Z Xu ldquoInsitu optical and Raman spectroscopic observations of the effectsof pressure and fluid composition on liquidliquid phase separa-tion in aqueous cadmium sulfate solutions (=400∘C 50MPa)with geological and geochemical implicationsrdquo Geochimica etCosmochimica Acta vol 211 pp 133ndash152 2017
[122] W L Marshall ldquoAmorphous silica solubilitiesmdashI Behavior inaqueous sodium nitrate solutions 25ndash300∘C 0ndash6 molalrdquo Geo-chimica et Cosmochimica Acta vol 44 no 7 pp 907ndash913 1980
[123] C-T A Chen andW LMarshall ldquoAmorphous silica solubilitiesIV Behavior in pure water and aqueous sodium chloridesodium sulfate magnesium chloride and magnesium sulfatesolutions up to 350∘Crdquo Geochimica et Cosmochimica Acta vol46 no 2 pp 279ndash287 1982
[124] B A Fleming and D A Crerar ldquoSilicic acid ionization and cal-culation of silica solubility at elevated temperature and pHapplication to geothermal fluid processing and reinjectionrdquoGeothermics vol 11 no 1 pp 15ndash29 1982
the hydrothermal alteration would increase the porosity ofthe dolomite reservoirs McKinley et al [29] reported thatthe total volume of minerals within a dolomite reservoir canbe reduced by 13 to 17 through the reaction betweendolomite and quartz in reaction (1) In addition the reactionbetween dolomite and silica-rich hydrothermal fluids can actas an important source of CO
2 in hydrocarbon reservoirsThepresence of CO2 can lower the pH of the formation waterand thus promote the dissolution of carbonate minerals [60107 108] increasing the porosity of the reservoirs [109ndash111]However the pore throats may be blocked by the formationof talc or other clay minerals [29 112] Therefore moredetailed factors should be considered in order to unequi-vocally evaluate the effects of silica-rich hydrothermal fluidsin dolomite reservoirs
Although talc can form from the interaction betweendolomite and silica-rich fluids at low temperatures it isseldom observed in hydrocarbon reservoirs [29 31] for thefollowing two reasons (1)A large amount of CO
2can be pro-
duced by the maturation of organic matter and the reactionbetween carbonate minerals and organic acid [98 101] Thepresence of CO
2decreases the lower thermal stability field
of talc [113] (2)The reaction path is dependent on the com-position of the hydrothermal fluid For example K+ andAl3+ are also important components of geological fluidsMontmorillonite instead of talc is more likely to form inthe presence of only a small quantity of Al3+ [41] and theformation of talc can also be inhibited by K+ [29]
43 Implications for High PndashT Experiment Using Fused SilicaCapillary Tubes as Reactors FSCCs are used to constructsynthetic fluid inclusions containing organic and inorganiccomponents [46] They offer advantages such as being inertto many components especially acids and S allowing forthe convenient synthesis of fluid inclusions and facilitatingin situ optical and Raman spectroscopic observations (eg[57 114ndash117]) Fused silica tubes can tolerate relatively hightemperatures up to 600∘C and pressures up to 300MPa As aresult FSCCs are used in many research fields For examplein addition to construction of synthetic fluid inclusions[46 53 118] FSCCs were used in studying the propertiesof hydrothermal fluids as optical and Raman spectroscopiccells [115ndash117 119ndash121] FSCCs were also used as reactorsin investigating the mechanism of thermochemical sulfatereduction [114] and the decomposition of organic matter[57]
However SiO2 in the FSCC acted as a reagent in thisstudy and was partially dissolved as indicated by the pitson the inner surface of the tube (Figures 8(a)ndash8(d)) Thedissolution of silica from FSCCs containing alkali sulfatesolutions was also observed after quenching from ge350∘C(Figures 8(e) and 8(f)) The severe dissolution of fused silicacan be ascribed to three factors (1) Amorphous silica ismore soluble than quartz especially at high temperaturesIn neutral solutions its solubility increases sharply withtemperature from 100 ppm at 20∘C to 1500 ppm at 310∘C[74 122 123] (2) Under basic conditions the solubility ofamorphous silica is greatly enhanced by the ionization ofsilicic acid (H
4SiO4+ OHminus rarr H
3SiO4
minus + H2O [124]) (3)
SiO2may act as a reagent as it did in this experiment The
presence of dissolution pits will weaken the mechanicalstrength of the silica tube In addition the presence ofdissolved silica can make the system more complicated thanexpected Therefore the solubility and reactivity of silicaunder hydrothermal conditions should be evaluated beforeFSCCs are used as reactors
5 Conclusion
The reactions in the CaMg(CO3)2ndashSiO2ndashH2O system atlow temperatures were investigated using fused silica tubesas reactors Results showed that dolomite reacted with asilica-rich fluid to form talc calcite and CO2 at le200
∘Cand low PCO2 The reaction rate increased with increasingtemperature and decreased with rising PCO2Therefore hightemperature and the presence of a conduit to release CO2 willpromote the formation of talcThis experiment has importantgeological and geochemical implications(1)Theresults confirmed themechanism of talcminerali-
zation in Mg-carbonate hosted talc deposits Dolomitereacted with silica-rich hydrothermal fluids to form talccalcite and CO
2 Talc could form at le200∘C whereas pre-
vious hydrothermal experiments examining the CaOndashMgOndashSiO2ndashCO2ndashH2O system were mainly conducted at gt250∘C
However considering the effect of temperature on thereaction rate and other geological conditions massive talcdeposits are still more likely to form at higher temperaturesThe formation of talc along a fault in a Mg-carbonateformation will also weaken the fault thus preventing strongearthquakes(2) Talc in carbonate reservoirs can indicate the activity
of silica-rich hydrothermal fluids Fluid-aided alteration ofdolomite can change the physical properties of dolomitereservoirs substantially The reaction between dolomite andquartz within the carbonate can decrease the total volume ofminerals by 13ndash17 The generation of CO2 can promotethe dissolution of carbonate minerals elsewhere under theappropriate conditions increasing the porosity and perme-ability of carbonate reservoirs However talc minerals mayblock pore throats in the reservoirs Therefore additionalfactors need to be considered when evaluating the effectsof CaMg(CO
3)2ndashSiO2ndashH2O interactions on the physical
properties of carbonate reservoirs(3) The solubility and reactivity of silica should be con-
sidered when using fused silica tubes as reactors in highPndashT experiments The dissolution of silica will increase thecomplexity of the system andweaken themechanical strengthof the tube
Conflicts of Interest
The authors declare that they have no conflicts of interest
Acknowledgments
The dolomite sample was provided by Mr Chunhua ShiMisses Yang Qu Wanlu Gao and Ye Qiu helped the authorsa lot during the micro-XRD analysis and HPOC experiment
10 Geofluids
Outer surfaceInner surface
(a) (b)In
ner s
urfa
ce
(c) (d)
Inner surface
(e) (f)
Figure 8 SEM images of the inner surface of the silica tube (a) Smooth inner surface before the reaction (b) magnification of the squarearea shown in (a) (c) dissolution pits on the inner surface after heating at 200∘C for sim60 days (d) magnification of (c) severe erosion of thesilica on the inner surface of FSCCs containing (e) 10m Na
2SO4and (f) 10m Li
2SO4after heating at 350∘C for 1 h
Dr Rui Wang and Miss Siyu Hu are also thanked for theirhelp in the thermodynamic calculations of the reactionsThis work was financially supported by the National NaturalScience Foundation of China (Grant nos 41230312 and41573054) I-Ming Chou is thankful for the support of theKnowledge Innovation Program (SIDSSE-201302) and theHadal-trench Research Program (XDB06060100) of ChineseAcademy of Sciences
References
[1] L D Meinert ldquoSkarns and skarn depositsrdquo Geoscience Canadavol 19 no 4 pp 145ndash162 1992
[2] L D Meinert G M Dipple and S Nicolescu ldquoWorld skarndepositsrdquo Economic Geology 100th Anniversary Volume pp299ndash336 2005
[3] Y Yao J Chen J Lu R Wang and R Zhang ldquoGeology andgenesis of the Hehuaping magnesian skarn-type cassiterite-sulfide deposit Hunan Province Southern ChinardquoOre GeologyReviews vol 58 no C pp 163ndash184 2014
[4] T M Gordon and H J Greenwood ldquoThe reaction dolomite+ quartz + water = talc + calcite + carbon dioxiderdquo AmericanJournal of Science vol 268 pp 225ndash242 1970
[5] M B Holness ldquoFluid flow paths and mechanisms of fluidinfiltration in carbonates during contact metamorphism TheBeinn an Dubhaich aureole Skyerdquo Journal of MetamorphicGeology vol 15 no 1 pp 59ndash70 1997
Geofluids 11
[6] W Heinrich S S Churakov andM Gottschalk ldquoMineral-fluidequilibria in the system CaOndashMgOndashSiO
2ndashH2OndashCO
2ndashNaCl
and the record of reactive fluid flow in contact metamorphicaureolesrdquo Contributions to Mineralogy and Petrology vol 148no 2 pp 131ndash149 2004
[7] M Wesołowski ldquoThermal decomposition of talc a reviewrdquoThermochimica Acta vol 78 no 1-3 pp 395ndash421 1984
[8] L A Perez-Maqueda A Duran and J L Perez-RodrıguezldquoPreparation of submicron talc particles by sonicationrdquoAppliedClay Science vol 28 no 1-4 pp 245ndash255 2005
[9] R L Johnson ldquoTalcrdquoAmerican Ceramic Society Bulletin vol 71pp 818ndash820 1992
[10] R L Johnson and R L Virta ldquoTalcrdquo American Ceramic SocietyBulletin vol 79 pp 79ndash81 2000
[11] M Z Abzalov ldquoChrome-spinels in gabbro-wehrlite intrusionsof the Pechenga area Kola Peninsula Russia emphasis onalteration featuresrdquo Lithos vol 43 no 3 pp 109ndash134 1998
[12] M F El-Sharkawy ldquoTalc mineralization of ultramafic affinity inthe Eastern Desert of Egyptrdquo Mineralium Deposita vol 35 no4 pp 346ndash363 2000
[13] M Franceschelli G Carcangiu A M Caredda G CrucianiI Memmi and M Zucca ldquoTransformation of cumulate maficrocks to granulite and re-equilibration in amphibolite andgreenschist facies in NE Sardinia Italyrdquo Lithos vol 63 no 1-2pp 1ndash18 2002
[14] S G Tesalina P Nimis T Auge and V V Zaykov ldquoOriginof chromite in mafic-ultramafic-hosted hydrothermal massivesulfides from the Main Uralian Fault South Urals RussiardquoLithos vol 70 no 1-2 pp 39ndash59 2003
[15] D M Evans ldquoMetamorphic modifications of the Muremeramafic-ultramafic intrusions eastern Burundi and their effecton chromite compositionsrdquo Journal of African Earth Sciencesvol 101 pp 19ndash34 2015
[16] T Yamanaka K Maeto H Akashi et al ldquoShallow submarinehydrothermal activity with significant contribution of mag-matic water producing talc chimneys in the Wakamiko CraterofKagoshimaBay southernKyushu Japanrdquo Journal of Volcanol-ogy and Geothermal Research vol 258 pp 74ndash84 2013
[17] B Moine J P Fortune P Moreau and F Viguier ldquoComparativemineralogy geochemistry and conditions of formation of twometasomatic talc and chlorite deposits Trimouns PyreneesFrance and Rabenwald eastern Alps Austriardquo Economic Geol-ogy vol 84 no 5 pp 1398ndash1416 1989
[18] W Prochaska ldquoGeochemistry and genesis of Austrian talcdepositsrdquo Applied Geochemistry vol 4 no 5 pp 511ndash525 1989
[19] P de Parseval S Jiang F Fontan R Wang F Martin and JFreeet ldquoGeology and ore genesis of the Trimouns talc-chloriteore deposit Pyrenees Francerdquo Acta Petrologica Sinica vol 20no 4 pp 877ndash886 2004
[20] A C Gondim and S Jiang ldquoGeologic characteristics and gene-ticmodels for the talc deposits in Parana andBahia BrazilrdquoActaPetrologica Sinica vol 20 no 4 pp 829ndash836 2004
[21] P Boulvais P de Parseval A DrsquoHulst and P Paris ldquoCarbonatealteration associated with talc-chlorite mineralization in theeastern Pyrenees with emphasis on the St Barthelemy MassifrdquoMineralogy and Petrology vol 88 no 3-4 pp 499ndash526 2006
[22] G R Davies and L B Smith Jr ldquoStructurally controlled hydro-thermal dolomite reservoir facies an overviewrdquoAAPG Bulletinvol 90 no 11 pp 1641ndash1690 2006
[23] J Lonnee and H G Machel ldquoPervasive dolomitization withsubsequent hydrothermal alteration in theClarke Lake gas field
Middle Devonian Slave Point Formation British ColumbiaCanadardquo AAPG Bulletin vol 90 no 11 pp 1739ndash1761 2006
[24] J A Luczaj ldquoEvidence against the Dorag (mixing-zone) modelfor dolomitization along theWisconsin arch - A case for hydro-thermal diagenesisrdquo AAPG Bulletin vol 90 no 11 pp 1719ndash1738 2006
[25] L B Smith Jr ldquoOrigin and reservoir characteristics of UpperOrdovician Trenton-Black River hydrothermal dolomite reser-voirs in New YorkrdquoAAPG Bulletin vol 90 no 11 pp 1691ndash17182006
[26] J Parnell ldquoDevonianMagadi-type cherts in theOrcadian BasinScotlandrdquo Journal of Sedimentary Petrology vol 56 no 4 pp495ndash500 1986
[27] J M Garcıa-Ruiz ldquoCarbonate precipitation into alkaline silica-rich environmentsrdquo Geology vol 26 no 9 pp 843ndash846 1998
[28] J Zhang W Hu Y Qian et al ldquoFormation of saddle dolomitesin Upper Cambrian carbonates western Tarim Basin (north-west China) implications for fault-related fluid flowrdquo Marineand Petroleum Geology vol 26 no 8 pp 1428ndash1440 2009
[29] J M McKinley R H Worden and A H Ruffell ldquoContactdiagenesis the effect of an intrusion on reservoir quality in thetriassic sherwood sandstone group Northern Irelandrdquo Journalof Sedimentary Research vol 71 no 3 pp 484ndash495 2001
[30] S Dong D Chen H Qing et al ldquoHydrothermal alteration ofdolostones in the Lower Ordovician Tarim Basin NW Chinamultiple constraints from petrology isotope geochemistry andfluid inclusion microthermometryrdquo Marine and PetroleumGeology vol 46 pp 270ndash286 2013
[31] V Madrucci C W D D Anjos R A Spadini D B Alvesand S M C Anjos ldquoAuthigenic magnesian clays in carbonatereservoirs in Brazilrdquo in Proceedings of the 15th International ClayConference Rio De Janeiro Brazil 2013
[32] C H Scholz ldquoEarthquakes and friction lawsrdquo Nature vol 391no 6662 pp 37ndash42 1998
[33] A M Schleicher B A Van Der Pluijm J G Solum andL N Warr ldquoOrigin and significance of clay-coated fracturesin mudrock fragments of the SAFOD borehole (ParkfieldCalifornia)rdquoGeophysical Research Letters vol 33 no 16 ArticleID L16313 2006
[34] A M Schleicher B A van der Pluijm and L N Warr ldquoNano-coatings of clay and creep of the San Andreas fault at ParkfieldCaliforniardquo Geology vol 38 no 7 pp 667ndash670 2010
[35] C Collettini C Viti S A F Smith and R E HoldsworthldquoDevelopment of interconnected talc networks and weakeningof continental low-angle normal faultsrdquo Geology vol 37 no 6pp 567ndash570 2009
[36] F Tornos and B F Spiro ldquoThe geology and isotope geochem-istry of the talc deposits of Puebla de Lillo (Cantabrian zonenorthern Spain)rdquo Economic Geology vol 95 no 6 pp 1277ndash1296 2000
[37] L Hecht R Freiberger H A Gilg G Grundmann and Y AKostitsyn ldquoRare earth element and isotope (C O Sr) charac-teristics of hydrothermal carbonates genetic implications fordolomite-hosted talc mineralization at Gopfersgrun (Fichtelge-birge Germany)rdquo Chemical Geology vol 155 no 1-2 pp 115ndash130 1999
[38] R Sharma P Joshi and P D Pant ldquoThe role of fluids inthe formation of talc deposits of Rema area Kumaun LesserHimalayardquo Journal of the Geological Society of India vol 73 no2 pp 237ndash248 2009
12 Geofluids
[39] P De Parseval B Moine J P Fortune and J Ferret ldquoFluid-mineral interactions at the origin of the Trimouns talc andchlorite deposit (Pyrenees France)rdquo in Current Research inGeology Applied to Ore Deposits P Fenoll Hach-Ali J Torrez-Ruiz and F Gervilla Eds pp 205ndash209 University of GranadaGranada Granada Spain 1993
[40] M C Boiron P Boulvais M Cathelineau D Banks N Cal-vayrac and G Hubert ldquoFluid circulation at the origin of thetrimouns talc deposit (Pyrenees France)rdquo in Proceedings of the18th Meeting of European Current Research on Fluid InclusionsSiena Italy 2005
[41] P Bayliss andA A Levhinson ldquoLow temperature hydrothermalsynthesis from dolomite or calcite quartz and kaoliniterdquo Claysand Clay Minerals vol 19 no 2 pp 109ndash114 1971
[42] G Skippen ldquoAn experimental model for low pressure meta-morphism of siliceous dolomitic marblerdquo American Journal ofScience vol 274 no 5 pp 487ndash509 1974
[43] J Slaughter D M Kerrick and V J Wall ldquoExperimen-tal and thermodynamic study of equilibria in the systemCaOndashMgOndashSiO
2ndashH2OndashCO
2rdquoAmerican Journal of Science vol
275 pp 143ndash162 1975[44] R G Eggert and D M Kerrick ldquoMetamorphic equilibria in the
siliceous dolomite system 6 kbar experimental data and geo-logic implicationsrdquo Geochimica et Cosmochimica Acta vol 45no 7 pp 1039ndash1049 1981
[45] Z Zhang and Z Duan ldquoPrediction of the PVT properties ofwater over wide range of temperatures and pressures frommolecular dynamics simulationrdquo Physics of the Earth andPlanetary Interiors vol 149 no 3-4 pp 335ndash354 2005
[46] I-M Chou Y Song and R C Burruss ldquoA newmethod for syn-thesizing fluid inclusions in fused silica capillaries containingorganic and inorganic materialrdquo Geochimica et CosmochimicaActa vol 72 no 21 pp 5217ndash5231 2008
[47] I-M Chou R C Burruss and W J Lu ldquoA new optical cellfor spectroscopic studies of geologic fluids at pressures up to100MPardquo in Advances in High-Pressure Technology for Geo-physical Applications J Chen YWang T S Duffy G Shen andL F Dobrzhinetakaya Eds pp 475ndash485 Elsevier AmsterdamNetherlands 2005
[48] K M Rosso and R J Bodnar ldquoMicrothermometric and Ramanspectroscopic detection limits of CO
2in fluid inclusions and the
Raman spectroscopic characterization of CO2rdquo Geochimica et
Cosmochimica Acta vol 59 no 19 pp 3961ndash3975 1995[49] H M Lamadrid Geochemistry of fluid-rock processes [Doctoral
dissertation] Virginia Polytechnic Institute and State Univer-sity Blacksburg VA USA 2016
[50] J H Parker D W Feldman and M Ashkin ldquoRaman scatteringby silicon and germaniumrdquo Physical Review vol 155 no 3 pp712ndash714 1967
[51] Y V Shvarov ldquoAlgorithmization of the numeric equilibriummodeling of dynamic geochemical processesrdquo GeochemistryInternational vol 37 no 6 pp 571ndash576 1999
[52] R B Wright and C H Wang ldquoDensity effect on the Fermiresonance in gaseous CO
2by Raman scatteringrdquoThe Journal of
Chemical Physics vol 58 no 7 pp 2893ndash2895 1973[53] XWang I-M ChouWHu R C Burruss Q Sun and Y Song
ldquoRaman spectroscopic measurements of CO2density experi-
mental calibration with high-pressure optical cell (HPOC) andfused silica capillary capsule (FSCC) with application to fluidinclusion observationsrdquo Geochimica et Cosmochimica Acta vol75 no 14 pp 4080ndash4093 2011
[54] H R Gordon and T K McCubbin Jr ldquoThe 28-micron bandsof CO
2rdquo Journal of Molecular Spectroscopy vol 19 no 1ndash4 pp
137ndash154 1966[55] T Azbej M J Severs B G Rusk and R J Bodnar ldquoIn situ
quantitative analysis of individual H2O-CO
2fluid inclusions by
laser Raman spectroscopyrdquo Chemical Geology vol 237 no 3-4pp 255ndash263 2007
[56] Y Song I M Chou W Hu B Robert and W Lu ldquoCO2
density-raman shift relation derived from synthetic inclusionsin fused silica capillaries and its applicationrdquo Acta GeologicaSinica (English Edition) vol 83 pp 932ndash938 2009
[57] Z Pan I-M Chou and R C Burruss ldquoHydrolysis of polycar-bonate in sub-critical water in fused silica capillary reactor within situ Raman spectroscopyrdquo Green Chemistry vol 11 no 8 pp1105ndash1107 2009
[58] M L Frezzotti F Tecce and A Casagli ldquoRaman spectroscopyfor fluid inclusion analysisrdquo Journal of Geochemical Explorationvol 112 pp 1ndash20 2012
[59] E L Shock and H C Helgeson ldquoCalculation of the thermo-dynamic and transport properties of aqueous species at highpressures and temperatures correlation algorithms for ionicspecies and equation of state predictions to 5 kb and 1000∘CrdquoGeochimica et Cosmochimica Acta vol 52 no 8 pp 2009ndash20361988
[60] O S Pokrovsky SVGolubev J Schott andACastillo ldquoCalcitedolomite and magnesite dissolution kinetics in aqueous solu-tions at acid to circumneutral pH 25 to 150∘C and 1 to 55 atmpCO2 New constraints on CO
2sequestration in sedimentary
basinsrdquo Chemical Geology vol 265 no 1-2 pp 20ndash32 2009[61] YGarrabos R Tufeu B LeNeindre G Zalczer andD Beysens
ldquoRayleigh andRaman scattering near the critical point of carbondioxiderdquo The Journal of Chemical Physics vol 72 no 8 pp4637ndash4651 1979
[62] J H Nicola J F Scott R M Couto andMM Correa ldquoRamanspectra of dolomite [CaMg(CO
3)2]rdquo Physical Review B vol 14
no 10 pp 4676ndash4678 1976[63] S Gunasekaran G Anbalagan and S Pandi ldquoRaman and
infrared spectra of carbonates of calcite structurerdquo Journal ofRaman Spectroscopy vol 37 no 9 pp 892ndash899 2006
[64] G J Rosasco and J J Blaha ldquoRaman microprobe spectra andvibrationalmode assignments of talcrdquoApplied Spectroscopy vol34 no 2 pp 140ndash144 1980
[65] V Trommsdorff and B W Evans ldquoAntigorite-ophicarbo-nates phase relations in a portion of the system CaOndashMgOndashSiO2ndashH2OndashCO
2rdquo Contributions to Mineralogy and Petrology
vol 60 no 1 pp 39ndash56 1977[66] V Trommsdorff and J A D Connolly ldquoConstraints on phase
diagram topology for the systemCaOndashMgOndashSiO2ndashCO2ndashH2Ordquo
Contributions to Mineralogy and Petrology vol 104 no 1 pp 1ndash7 1990
[67] B S Van Gosen H A Lowers S J Sutley and C A GentldquoUsing the geologic setting of talc deposits as an indicator ofamphibole asbestos contentrdquo Environmental Geology vol 45no 7 pp 920ndash939 2004
[68] W Johannes ldquoAn experimental investigation of the systemMgO-SiO
2-H2O-CO
2rdquo American Journal of Science vol 267
no 9 pp 1083ndash1104 1969[69] E S Schandl and M P Gorton ldquoHydrothermal alteration and
CO2metasomatism (natural carbon sequestration) of komati-
ites in the south-western Abitibi greenstone beltrdquo CanadianMineralogist vol 50 no 1 pp 129ndash146 2012
Geofluids 13
[70] B W Evans and S Guggenheim ldquoTalc phyrophyllite andrelated mineralsrdquo in Reviews in Mineralogy S W Bailey Edvol 19 pp 225ndash294 1988
[71] B Velde ldquoExperimental pseudomorphism of diopside by talcand serpentine in (Ni Mg)Cl
2aqueous solutionsrdquo Geochimica
et Cosmochimica Acta vol 52 no 2 pp 415ndash424 1988[72] A E Williams-Jones C Normand H Clark Vali Jr R F
Martin A Dufresne and Nayebzadeh A ldquoControls of amphi-bole formation in chrysotile from the Jeffrey Mine AsbestosQuebecrdquo inTheHealth Effects Effects of Chrysotile Asbestos R PNolan AM LangerM RossWicks F J andMartin F R Edsvol 5 pp 89ndash104 The Mineralogical Association of CanadaQuebec Quebec Canada 2001
[73] B W Evans ldquoThe serpentinite multisystem revisited chrysotileis metastablerdquo International Geology Review vol 46 no 6 pp479ndash506 2004
[74] I Gunnarsson and S Arnorsson ldquoAmorphous silica solubilityand the thermodynamic properties of H
4SiO∘4in the range of
0∘ to 350∘C at Psatrdquo Geochimica et Cosmochimica Acta vol 64no 13 pp 2295ndash2307 2000
[75] M W Bodine Jr ldquoTrioctahedral clay mineral assemblages inPaleozoic marine evaporite rocksrdquo in Proceedings of the Pre-sented in the Sixth International Symposium on Salt vol 1 pp267ndash284 Toronto Canada 1983
[76] W Schreyer and K Abraham ldquoThree-stage metamorphic his-tory of a whiteschist from Sar e Sang Afghanistan as part ofa former evaporite depositrdquo Contributions to Mineralogy andPetrology vol 59 no 2 pp 111ndash130 1976
[77] T Angerer and S G Hagemann ldquoThe BIF-hosted high-gradeiron ore deposits in the archean koolyanobbing greenstonebelt Western Australia structural control on synorogenic-and weathering-related magnetite- hematite- and goethite-rich iron orerdquo Economic Geology vol 105 no 5 pp 917ndash9452010
[78] P Duuring and S Hagemann ldquoLeaching of silica bands andconcentration of magnetite in Archean BIF by hypogene fluidsBeebyn Fe ore deposit Yilgarn Craton Western AustraliardquoMineralium Deposita vol 48 no 3 pp 341ndash370 2013
[79] D Shin and I Lee ldquoFluid inclusions and their stable isotopegeochemistry of the carbonate-hosted talc deposits near theCretaceous Muamsa Granite South Koreardquo Geochemical Jour-nal vol 40 no 1 pp 69ndash85 2006
[80] P G Novgorodov ldquoSolubility of quartz in anH2OndashCO
2mixture
at 700 degrees C and pressures of 3 and 5 kbarsrdquoGeokhimiya pp1484ndash1489 1975
[81] T M Gerlach ldquoChemical characteristics of the volcanic gasesfrom Nyiragongo lava lake and the generation of CH
4-rich
fluid inclusions in alkaline rocksrdquo Journal of Volcanology ampGeothermal Research vol 8 no 2-4 pp 177ndash189 1980
[82] J V Walther and P M Orville ldquoVolatile production and trans-port in regional metamorphismrdquo Contributions to Mineralogyand Petrology vol 79 no 3 pp 252ndash257 1982
[83] W F Giggenbach ldquoThe origin and evolution of fluids inmagmatic-hydrothermal systemsrdquo in Geochemistry of Hydro-thermalOreDeposits H L Barnes Ed pp 737ndash796WileyNewYork NY USA 3 edition 1997
[84] J B Lowenstern ldquoCarbon dioxide in magmas and implicationsfor hydrothermal systemsrdquoMineralium Deposita vol 36 no 6pp 490ndash502 2001
[85] R Kerrich and W S Fyfe ldquoThe gold-carbonate associationsource of CO
2 and CO
2fixation reactions in Archaean lode
depositsrdquo Chemical Geology vol 33 no 1ndash4 pp 265ndash294 1981
[86] P I Nabelek ldquoCalc-silicate reactions and bedding-controlledisotopic exchange in the Notch Peak aureole Utah implicationsfor differential fluid fluxes with metamorphic graderdquo Journal ofMetamorphic Geology vol 20 no 4 pp 429ndash440 2002
[87] P I Nabelek ldquoFluid evolution and kinetics of metamorphicreactions in calc-silicate contact aureoles - From H
2O to CO
2
and backrdquo Geology vol 35 no 10 pp 927ndash930 2007[88] H G Machel ldquoBacterial and thermochemical sulfate reduction
in diagenetic settings - old and new insightsrdquo SedimentaryGeology vol 140 no 1-2 pp 143ndash175 2001
[89] L Stalker P Farrimond and S R Larter ldquoWater as an oxygensource for the production of oxygenated compounds (includingCO2precursors) during kerogen maturationrdquo Organic Geo-
chemistry vol 22 no 3-5 pp 477ndashIN4 1994[90] Z K Shipton J P Evans D Kirschner P T Kolesar A P
Williams and J Heath ldquoAnalysis of CO2leakage through lsquolow-
permeabilityrsquo faults from natural reservoirs in the ColoradoPlateau east-central Utahrdquo Geological Society Special Publica-tion vol 233 pp 43ndash58 2004
[91] J Byerlee ldquoFriction overpressure and fault normal compres-sionrdquo Geophysical Research Letters vol 17 no 12 pp 2109ndash21121990
[92] C Morrow B Radney and J Byerlee ldquoChapter 3 frictionalstrength and the effective pressure law of montmorillonite andlllite claysrdquo International Geophysics vol 51 no C pp 69ndash881992
[93] C A Morrow D E Moore and D A Lockner ldquoThe effectof mineral bond strength and adsorbed water on fault gougefrictional strengthrdquo Geophysical Research Letters vol 27 no 6pp 815ndash818 2000
[94] D A Lockner C Morrow D Moore and S Hickman ldquoLowstrength of deep San Andreas fault gouge from SAFOD corerdquoNature vol 472 no 7341 pp 82ndash86 2011
[95] D EMoore andM J Rymer ldquoTalc-bearing serpentinite and thecreeping section of the San Andreas faultrdquo Nature vol 448 no7155 pp 795ndash797 2007
[96] DH Zenger ldquoDiscussion lsquoOn the formation and occurrence ofsaddle dolomitersquordquo Journal of Sedimentary Petrology vol 51 no4 pp 1350ndash1352 1981
[97] DAKatzG P Eberli P K Swart andL B Smith Jr ldquoTectonic-hydrothermal brecciation associated with calcite precipitationand permeability destruction in Mississippian carbonate reser-voirs Montana and Wyomingrdquo AAPG Bulletin vol 90 no 11pp 1803ndash1841 2006
[98] M Esteban and C Taberner ldquoSecondary porosity developmentduring late burial in carbonate reservoirs as a result of mixingandor cooling of brinesrdquo Journal of Geochemical Explorationvol 78-79 pp 355ndash359 2003
[99] H G MacHel ldquoInvestigations of burial diagenesis in carbonatehydrocarbon reservoir rocksrdquoGeoscience Canada vol 32 no 3pp 103ndash128 2005
[100] J A Sagan and B S Hart ldquoThree-dimensional seismic-baseddefinition of fault-related porosity development Trenton-BlackRiver interval Saybrook Ohiordquo AAPG Bulletin vol 90 no 11pp 1763ndash1785 2006
[101] F Xing and S Li ldquoGenesis and environment characteristics ofdolomite-hosted quartz and its significance for hydrocarbonexploration in Keping Area Tarim Basin Chinardquo Journal ofEarth Science vol 23 no 4 pp 476ndash489 2012
[102] L Yun and Z Cao ldquoHydrocarbon enrichment pattern andexploration potential of the Ordovician in Shunnan area TarimBasinrdquo Oil and Gas Geology vol 35 no 6 pp 788ndash797 2014
14 Geofluids
[103] Y Li N Ye X Yuan Q Huang B Su and R Zhou ldquoGeologicaland geochemical characteristics of silicified hydrothermal fluidsin Well Shunnan 4 Tarim Basinrdquo Oil and Gas Geology vol 36no 6 pp 934ndash944 2015
[104] L Qi ldquoOil and gas breakthrough in ultra-deep Ordoviciancarbonate formations in Shuntuoguole uplift Tarim BasinrdquoChina Petroleum Exploration vol 21 no 3 pp 38ndash51 2016 (inChinese with English abstract)
[105] H R Qing ldquoAn introduction of petrology and diagenesis ofultra-deep water carbonate reservoirs from the Atlantic Oceanoffshore Brazilrdquo 2017 Oral presentation at Wuxi Institute ofPetroleum Geology of SINOPEC Wuxi China
[106] G J Simandl and S Paradisl ldquoCarbonate-hosted talcrdquo SelectedBritish ColumbiaMineral Deposit Profiles vol 3 pp 35ndash38 1999
[107] Y K Kharaka D R Cole S D Hovorka W D Gunter K GKnauss and BM Freifeld ldquoGas-water-rock interactions in FrioFormation following CO
2injection implications for the storage
of greenhouse gases in sedimentary basinsrdquoGeology vol 34 no7 pp 577ndash580 2006
[108] Z Duan and D Li ldquoCoupled phase and aqueous speciesequilibrium of the H
2OndashCO
2ndashNaClndashCaCO
3system from 0 to
250∘C 1 to 1000 bar with NaCl concentrations up to saturationof haliterdquo Geochimica et Cosmochimica Acta vol 72 no 20 pp5128ndash5145 2008
[109] M R Giles and J DMarshall ldquoConstraints on the developmentof secondary porosity in the subsurface re-evaluation of pro-cessesrdquoMarine and PetroleumGeology vol 3 no 3 pp 243ndash2551986
[110] O S Pokrovsky S V Golubev and J Schott ldquoDissolution kinet-ics of calcite dolomite and magnesite at 25∘C and 0 to 50 atmpCO2rdquo Chemical Geology vol 217 no 3-4 pp 239ndash255 2005
[111] P Cao Z T Karpyn and L Li ldquoThe role of host rock pro-perties in determining potential CO
2migration pathwaysrdquo
International Journal of Greenhouse Gas Control vol 45 pp 18ndash26 2016
[112] M D Fishburn ldquoSignificant results of deep drilling at ElkHills Kern County Californiardquo in Structure Stratigraphy andHydrocarbon Occurrences of the San Joaquin Basin CaliforniaG K Kuespert and S A Reid Eds vol 64 pp 157ndash167 PacificSections Society of Economic Paleontologists and Mineralo-gists and American Association of Petroleum Geologists 1990
[113] E Povoden M Horacek and R Abart ldquoContact metamor-phism of siliceous dolomite and impure limestones from theWerfen formation in the eastern Monzoni contact aureolerdquoMineralogy and Petrology vol 76 no 1-2 pp 99ndash120 2002
[114] S Yuan I-M Chou R C Burruss X Wang and J Li ldquoDispro-portionation and thermochemical sulfate reduction reactions inSndashH2OndashCH
4and SndashD
2OndashCH
4systems from 200 to 340∘C at
elevated pressuresrdquo Geochimica et Cosmochimica Acta vol 118pp 263ndash275 2013
[115] X Wang I-M Chou W Hu and R C Burruss ldquoIn situ obser-vations of liquid-liquid phase separation in aqueous MgSO
4
solutions geological and geochemical implicationsrdquo Geochim-ica et Cosmochimica Acta vol 103 pp 1ndash10 2013
[116] X Wang Y Wan W Hu et al ldquoIn situ observations of liquid-liquid phase separation in aqueous ZnSO
4solutions at tem-
peratures up to 400∘C Implications for Zn2+ndashSO2minus4
[117] X Wang IM Chou W Hu Y Wan and Z Li ldquoPropertiesof lithium under hydrothermal conditions revealed by in situ
Raman spectroscopic characterization of Li2O-SO
3-H2O(D2O)
systems at temperatures up to 420∘Crdquo Chemical Geology vol451 pp 104ndash115 2017
[118] L Shang I-M Chou W Lu R C Burruss and Y ZhangldquoDetermination of diffusion coefficients of hydrogen in fusedsilica between 296 and 523 K by Raman spectroscopy and appli-cation of fused silica capillaries in studying redox reactionsrdquoGeochimica et CosmochimicaActa vol 73 no 18 pp 5435ndash54432009
[119] M Dargent J Dubessy L Truche E F Bazarkina C Nguyen-Trung and P Robert ldquoExperimental study of uranyl(VI) chlo-ride complex formation in acidic LiCl aqueous solutions underhydrothermal conditions (T = 21∘Cndash350∘C Psat) using Ramanspectroscopyrdquo European Journal ofMineralogy vol 25 no 5 pp765ndash775 2013
[120] YWanXWangWHu and I-MChou ldquoRaman spectroscopicobservations of the ion association between Mg2+ and SO2minus
4
in MgSO4-saturated droplets at temperatures of le380∘Crdquo The
Journal of Physical Chemistry A vol 119 no 34 pp 9027ndash90362015
[121] Y Wan X Wang W Hu I M Chou Y Chen and Z Xu ldquoInsitu optical and Raman spectroscopic observations of the effectsof pressure and fluid composition on liquidliquid phase separa-tion in aqueous cadmium sulfate solutions (=400∘C 50MPa)with geological and geochemical implicationsrdquo Geochimica etCosmochimica Acta vol 211 pp 133ndash152 2017
[122] W L Marshall ldquoAmorphous silica solubilitiesmdashI Behavior inaqueous sodium nitrate solutions 25ndash300∘C 0ndash6 molalrdquo Geo-chimica et Cosmochimica Acta vol 44 no 7 pp 907ndash913 1980
[123] C-T A Chen andW LMarshall ldquoAmorphous silica solubilitiesIV Behavior in pure water and aqueous sodium chloridesodium sulfate magnesium chloride and magnesium sulfatesolutions up to 350∘Crdquo Geochimica et Cosmochimica Acta vol46 no 2 pp 279ndash287 1982
[124] B A Fleming and D A Crerar ldquoSilicic acid ionization and cal-culation of silica solubility at elevated temperature and pHapplication to geothermal fluid processing and reinjectionrdquoGeothermics vol 11 no 1 pp 15ndash29 1982
Figure 8 SEM images of the inner surface of the silica tube (a) Smooth inner surface before the reaction (b) magnification of the squarearea shown in (a) (c) dissolution pits on the inner surface after heating at 200∘C for sim60 days (d) magnification of (c) severe erosion of thesilica on the inner surface of FSCCs containing (e) 10m Na
2SO4and (f) 10m Li
2SO4after heating at 350∘C for 1 h
Dr Rui Wang and Miss Siyu Hu are also thanked for theirhelp in the thermodynamic calculations of the reactionsThis work was financially supported by the National NaturalScience Foundation of China (Grant nos 41230312 and41573054) I-Ming Chou is thankful for the support of theKnowledge Innovation Program (SIDSSE-201302) and theHadal-trench Research Program (XDB06060100) of ChineseAcademy of Sciences
References
[1] L D Meinert ldquoSkarns and skarn depositsrdquo Geoscience Canadavol 19 no 4 pp 145ndash162 1992
[2] L D Meinert G M Dipple and S Nicolescu ldquoWorld skarndepositsrdquo Economic Geology 100th Anniversary Volume pp299ndash336 2005
[3] Y Yao J Chen J Lu R Wang and R Zhang ldquoGeology andgenesis of the Hehuaping magnesian skarn-type cassiterite-sulfide deposit Hunan Province Southern ChinardquoOre GeologyReviews vol 58 no C pp 163ndash184 2014
[4] T M Gordon and H J Greenwood ldquoThe reaction dolomite+ quartz + water = talc + calcite + carbon dioxiderdquo AmericanJournal of Science vol 268 pp 225ndash242 1970
[5] M B Holness ldquoFluid flow paths and mechanisms of fluidinfiltration in carbonates during contact metamorphism TheBeinn an Dubhaich aureole Skyerdquo Journal of MetamorphicGeology vol 15 no 1 pp 59ndash70 1997
Geofluids 11
[6] W Heinrich S S Churakov andM Gottschalk ldquoMineral-fluidequilibria in the system CaOndashMgOndashSiO
2ndashH2OndashCO
2ndashNaCl
and the record of reactive fluid flow in contact metamorphicaureolesrdquo Contributions to Mineralogy and Petrology vol 148no 2 pp 131ndash149 2004
[7] M Wesołowski ldquoThermal decomposition of talc a reviewrdquoThermochimica Acta vol 78 no 1-3 pp 395ndash421 1984
[8] L A Perez-Maqueda A Duran and J L Perez-RodrıguezldquoPreparation of submicron talc particles by sonicationrdquoAppliedClay Science vol 28 no 1-4 pp 245ndash255 2005
[9] R L Johnson ldquoTalcrdquoAmerican Ceramic Society Bulletin vol 71pp 818ndash820 1992
[10] R L Johnson and R L Virta ldquoTalcrdquo American Ceramic SocietyBulletin vol 79 pp 79ndash81 2000
[11] M Z Abzalov ldquoChrome-spinels in gabbro-wehrlite intrusionsof the Pechenga area Kola Peninsula Russia emphasis onalteration featuresrdquo Lithos vol 43 no 3 pp 109ndash134 1998
[12] M F El-Sharkawy ldquoTalc mineralization of ultramafic affinity inthe Eastern Desert of Egyptrdquo Mineralium Deposita vol 35 no4 pp 346ndash363 2000
[13] M Franceschelli G Carcangiu A M Caredda G CrucianiI Memmi and M Zucca ldquoTransformation of cumulate maficrocks to granulite and re-equilibration in amphibolite andgreenschist facies in NE Sardinia Italyrdquo Lithos vol 63 no 1-2pp 1ndash18 2002
[14] S G Tesalina P Nimis T Auge and V V Zaykov ldquoOriginof chromite in mafic-ultramafic-hosted hydrothermal massivesulfides from the Main Uralian Fault South Urals RussiardquoLithos vol 70 no 1-2 pp 39ndash59 2003
[15] D M Evans ldquoMetamorphic modifications of the Muremeramafic-ultramafic intrusions eastern Burundi and their effecton chromite compositionsrdquo Journal of African Earth Sciencesvol 101 pp 19ndash34 2015
[16] T Yamanaka K Maeto H Akashi et al ldquoShallow submarinehydrothermal activity with significant contribution of mag-matic water producing talc chimneys in the Wakamiko CraterofKagoshimaBay southernKyushu Japanrdquo Journal of Volcanol-ogy and Geothermal Research vol 258 pp 74ndash84 2013
[17] B Moine J P Fortune P Moreau and F Viguier ldquoComparativemineralogy geochemistry and conditions of formation of twometasomatic talc and chlorite deposits Trimouns PyreneesFrance and Rabenwald eastern Alps Austriardquo Economic Geol-ogy vol 84 no 5 pp 1398ndash1416 1989
[18] W Prochaska ldquoGeochemistry and genesis of Austrian talcdepositsrdquo Applied Geochemistry vol 4 no 5 pp 511ndash525 1989
[19] P de Parseval S Jiang F Fontan R Wang F Martin and JFreeet ldquoGeology and ore genesis of the Trimouns talc-chloriteore deposit Pyrenees Francerdquo Acta Petrologica Sinica vol 20no 4 pp 877ndash886 2004
[20] A C Gondim and S Jiang ldquoGeologic characteristics and gene-ticmodels for the talc deposits in Parana andBahia BrazilrdquoActaPetrologica Sinica vol 20 no 4 pp 829ndash836 2004
[21] P Boulvais P de Parseval A DrsquoHulst and P Paris ldquoCarbonatealteration associated with talc-chlorite mineralization in theeastern Pyrenees with emphasis on the St Barthelemy MassifrdquoMineralogy and Petrology vol 88 no 3-4 pp 499ndash526 2006
[22] G R Davies and L B Smith Jr ldquoStructurally controlled hydro-thermal dolomite reservoir facies an overviewrdquoAAPG Bulletinvol 90 no 11 pp 1641ndash1690 2006
[23] J Lonnee and H G Machel ldquoPervasive dolomitization withsubsequent hydrothermal alteration in theClarke Lake gas field
Middle Devonian Slave Point Formation British ColumbiaCanadardquo AAPG Bulletin vol 90 no 11 pp 1739ndash1761 2006
[24] J A Luczaj ldquoEvidence against the Dorag (mixing-zone) modelfor dolomitization along theWisconsin arch - A case for hydro-thermal diagenesisrdquo AAPG Bulletin vol 90 no 11 pp 1719ndash1738 2006
[25] L B Smith Jr ldquoOrigin and reservoir characteristics of UpperOrdovician Trenton-Black River hydrothermal dolomite reser-voirs in New YorkrdquoAAPG Bulletin vol 90 no 11 pp 1691ndash17182006
[26] J Parnell ldquoDevonianMagadi-type cherts in theOrcadian BasinScotlandrdquo Journal of Sedimentary Petrology vol 56 no 4 pp495ndash500 1986
[27] J M Garcıa-Ruiz ldquoCarbonate precipitation into alkaline silica-rich environmentsrdquo Geology vol 26 no 9 pp 843ndash846 1998
[28] J Zhang W Hu Y Qian et al ldquoFormation of saddle dolomitesin Upper Cambrian carbonates western Tarim Basin (north-west China) implications for fault-related fluid flowrdquo Marineand Petroleum Geology vol 26 no 8 pp 1428ndash1440 2009
[29] J M McKinley R H Worden and A H Ruffell ldquoContactdiagenesis the effect of an intrusion on reservoir quality in thetriassic sherwood sandstone group Northern Irelandrdquo Journalof Sedimentary Research vol 71 no 3 pp 484ndash495 2001
[30] S Dong D Chen H Qing et al ldquoHydrothermal alteration ofdolostones in the Lower Ordovician Tarim Basin NW Chinamultiple constraints from petrology isotope geochemistry andfluid inclusion microthermometryrdquo Marine and PetroleumGeology vol 46 pp 270ndash286 2013
[31] V Madrucci C W D D Anjos R A Spadini D B Alvesand S M C Anjos ldquoAuthigenic magnesian clays in carbonatereservoirs in Brazilrdquo in Proceedings of the 15th International ClayConference Rio De Janeiro Brazil 2013
[32] C H Scholz ldquoEarthquakes and friction lawsrdquo Nature vol 391no 6662 pp 37ndash42 1998
[33] A M Schleicher B A Van Der Pluijm J G Solum andL N Warr ldquoOrigin and significance of clay-coated fracturesin mudrock fragments of the SAFOD borehole (ParkfieldCalifornia)rdquoGeophysical Research Letters vol 33 no 16 ArticleID L16313 2006
[34] A M Schleicher B A van der Pluijm and L N Warr ldquoNano-coatings of clay and creep of the San Andreas fault at ParkfieldCaliforniardquo Geology vol 38 no 7 pp 667ndash670 2010
[35] C Collettini C Viti S A F Smith and R E HoldsworthldquoDevelopment of interconnected talc networks and weakeningof continental low-angle normal faultsrdquo Geology vol 37 no 6pp 567ndash570 2009
[36] F Tornos and B F Spiro ldquoThe geology and isotope geochem-istry of the talc deposits of Puebla de Lillo (Cantabrian zonenorthern Spain)rdquo Economic Geology vol 95 no 6 pp 1277ndash1296 2000
[37] L Hecht R Freiberger H A Gilg G Grundmann and Y AKostitsyn ldquoRare earth element and isotope (C O Sr) charac-teristics of hydrothermal carbonates genetic implications fordolomite-hosted talc mineralization at Gopfersgrun (Fichtelge-birge Germany)rdquo Chemical Geology vol 155 no 1-2 pp 115ndash130 1999
[38] R Sharma P Joshi and P D Pant ldquoThe role of fluids inthe formation of talc deposits of Rema area Kumaun LesserHimalayardquo Journal of the Geological Society of India vol 73 no2 pp 237ndash248 2009
12 Geofluids
[39] P De Parseval B Moine J P Fortune and J Ferret ldquoFluid-mineral interactions at the origin of the Trimouns talc andchlorite deposit (Pyrenees France)rdquo in Current Research inGeology Applied to Ore Deposits P Fenoll Hach-Ali J Torrez-Ruiz and F Gervilla Eds pp 205ndash209 University of GranadaGranada Granada Spain 1993
[40] M C Boiron P Boulvais M Cathelineau D Banks N Cal-vayrac and G Hubert ldquoFluid circulation at the origin of thetrimouns talc deposit (Pyrenees France)rdquo in Proceedings of the18th Meeting of European Current Research on Fluid InclusionsSiena Italy 2005
[41] P Bayliss andA A Levhinson ldquoLow temperature hydrothermalsynthesis from dolomite or calcite quartz and kaoliniterdquo Claysand Clay Minerals vol 19 no 2 pp 109ndash114 1971
[42] G Skippen ldquoAn experimental model for low pressure meta-morphism of siliceous dolomitic marblerdquo American Journal ofScience vol 274 no 5 pp 487ndash509 1974
[43] J Slaughter D M Kerrick and V J Wall ldquoExperimen-tal and thermodynamic study of equilibria in the systemCaOndashMgOndashSiO
2ndashH2OndashCO
2rdquoAmerican Journal of Science vol
275 pp 143ndash162 1975[44] R G Eggert and D M Kerrick ldquoMetamorphic equilibria in the
siliceous dolomite system 6 kbar experimental data and geo-logic implicationsrdquo Geochimica et Cosmochimica Acta vol 45no 7 pp 1039ndash1049 1981
[45] Z Zhang and Z Duan ldquoPrediction of the PVT properties ofwater over wide range of temperatures and pressures frommolecular dynamics simulationrdquo Physics of the Earth andPlanetary Interiors vol 149 no 3-4 pp 335ndash354 2005
[46] I-M Chou Y Song and R C Burruss ldquoA newmethod for syn-thesizing fluid inclusions in fused silica capillaries containingorganic and inorganic materialrdquo Geochimica et CosmochimicaActa vol 72 no 21 pp 5217ndash5231 2008
[47] I-M Chou R C Burruss and W J Lu ldquoA new optical cellfor spectroscopic studies of geologic fluids at pressures up to100MPardquo in Advances in High-Pressure Technology for Geo-physical Applications J Chen YWang T S Duffy G Shen andL F Dobrzhinetakaya Eds pp 475ndash485 Elsevier AmsterdamNetherlands 2005
[48] K M Rosso and R J Bodnar ldquoMicrothermometric and Ramanspectroscopic detection limits of CO
2in fluid inclusions and the
Raman spectroscopic characterization of CO2rdquo Geochimica et
Cosmochimica Acta vol 59 no 19 pp 3961ndash3975 1995[49] H M Lamadrid Geochemistry of fluid-rock processes [Doctoral
dissertation] Virginia Polytechnic Institute and State Univer-sity Blacksburg VA USA 2016
[50] J H Parker D W Feldman and M Ashkin ldquoRaman scatteringby silicon and germaniumrdquo Physical Review vol 155 no 3 pp712ndash714 1967
[51] Y V Shvarov ldquoAlgorithmization of the numeric equilibriummodeling of dynamic geochemical processesrdquo GeochemistryInternational vol 37 no 6 pp 571ndash576 1999
[52] R B Wright and C H Wang ldquoDensity effect on the Fermiresonance in gaseous CO
2by Raman scatteringrdquoThe Journal of
Chemical Physics vol 58 no 7 pp 2893ndash2895 1973[53] XWang I-M ChouWHu R C Burruss Q Sun and Y Song
ldquoRaman spectroscopic measurements of CO2density experi-
mental calibration with high-pressure optical cell (HPOC) andfused silica capillary capsule (FSCC) with application to fluidinclusion observationsrdquo Geochimica et Cosmochimica Acta vol75 no 14 pp 4080ndash4093 2011
[54] H R Gordon and T K McCubbin Jr ldquoThe 28-micron bandsof CO
2rdquo Journal of Molecular Spectroscopy vol 19 no 1ndash4 pp
137ndash154 1966[55] T Azbej M J Severs B G Rusk and R J Bodnar ldquoIn situ
quantitative analysis of individual H2O-CO
2fluid inclusions by
laser Raman spectroscopyrdquo Chemical Geology vol 237 no 3-4pp 255ndash263 2007
[56] Y Song I M Chou W Hu B Robert and W Lu ldquoCO2
density-raman shift relation derived from synthetic inclusionsin fused silica capillaries and its applicationrdquo Acta GeologicaSinica (English Edition) vol 83 pp 932ndash938 2009
[57] Z Pan I-M Chou and R C Burruss ldquoHydrolysis of polycar-bonate in sub-critical water in fused silica capillary reactor within situ Raman spectroscopyrdquo Green Chemistry vol 11 no 8 pp1105ndash1107 2009
[58] M L Frezzotti F Tecce and A Casagli ldquoRaman spectroscopyfor fluid inclusion analysisrdquo Journal of Geochemical Explorationvol 112 pp 1ndash20 2012
[59] E L Shock and H C Helgeson ldquoCalculation of the thermo-dynamic and transport properties of aqueous species at highpressures and temperatures correlation algorithms for ionicspecies and equation of state predictions to 5 kb and 1000∘CrdquoGeochimica et Cosmochimica Acta vol 52 no 8 pp 2009ndash20361988
[60] O S Pokrovsky SVGolubev J Schott andACastillo ldquoCalcitedolomite and magnesite dissolution kinetics in aqueous solu-tions at acid to circumneutral pH 25 to 150∘C and 1 to 55 atmpCO2 New constraints on CO
2sequestration in sedimentary
basinsrdquo Chemical Geology vol 265 no 1-2 pp 20ndash32 2009[61] YGarrabos R Tufeu B LeNeindre G Zalczer andD Beysens
ldquoRayleigh andRaman scattering near the critical point of carbondioxiderdquo The Journal of Chemical Physics vol 72 no 8 pp4637ndash4651 1979
[62] J H Nicola J F Scott R M Couto andMM Correa ldquoRamanspectra of dolomite [CaMg(CO
3)2]rdquo Physical Review B vol 14
no 10 pp 4676ndash4678 1976[63] S Gunasekaran G Anbalagan and S Pandi ldquoRaman and
infrared spectra of carbonates of calcite structurerdquo Journal ofRaman Spectroscopy vol 37 no 9 pp 892ndash899 2006
[64] G J Rosasco and J J Blaha ldquoRaman microprobe spectra andvibrationalmode assignments of talcrdquoApplied Spectroscopy vol34 no 2 pp 140ndash144 1980
[65] V Trommsdorff and B W Evans ldquoAntigorite-ophicarbo-nates phase relations in a portion of the system CaOndashMgOndashSiO2ndashH2OndashCO
2rdquo Contributions to Mineralogy and Petrology
vol 60 no 1 pp 39ndash56 1977[66] V Trommsdorff and J A D Connolly ldquoConstraints on phase
diagram topology for the systemCaOndashMgOndashSiO2ndashCO2ndashH2Ordquo
Contributions to Mineralogy and Petrology vol 104 no 1 pp 1ndash7 1990
[67] B S Van Gosen H A Lowers S J Sutley and C A GentldquoUsing the geologic setting of talc deposits as an indicator ofamphibole asbestos contentrdquo Environmental Geology vol 45no 7 pp 920ndash939 2004
[68] W Johannes ldquoAn experimental investigation of the systemMgO-SiO
2-H2O-CO
2rdquo American Journal of Science vol 267
no 9 pp 1083ndash1104 1969[69] E S Schandl and M P Gorton ldquoHydrothermal alteration and
CO2metasomatism (natural carbon sequestration) of komati-
ites in the south-western Abitibi greenstone beltrdquo CanadianMineralogist vol 50 no 1 pp 129ndash146 2012
Geofluids 13
[70] B W Evans and S Guggenheim ldquoTalc phyrophyllite andrelated mineralsrdquo in Reviews in Mineralogy S W Bailey Edvol 19 pp 225ndash294 1988
[71] B Velde ldquoExperimental pseudomorphism of diopside by talcand serpentine in (Ni Mg)Cl
2aqueous solutionsrdquo Geochimica
et Cosmochimica Acta vol 52 no 2 pp 415ndash424 1988[72] A E Williams-Jones C Normand H Clark Vali Jr R F
Martin A Dufresne and Nayebzadeh A ldquoControls of amphi-bole formation in chrysotile from the Jeffrey Mine AsbestosQuebecrdquo inTheHealth Effects Effects of Chrysotile Asbestos R PNolan AM LangerM RossWicks F J andMartin F R Edsvol 5 pp 89ndash104 The Mineralogical Association of CanadaQuebec Quebec Canada 2001
[73] B W Evans ldquoThe serpentinite multisystem revisited chrysotileis metastablerdquo International Geology Review vol 46 no 6 pp479ndash506 2004
[74] I Gunnarsson and S Arnorsson ldquoAmorphous silica solubilityand the thermodynamic properties of H
4SiO∘4in the range of
0∘ to 350∘C at Psatrdquo Geochimica et Cosmochimica Acta vol 64no 13 pp 2295ndash2307 2000
[75] M W Bodine Jr ldquoTrioctahedral clay mineral assemblages inPaleozoic marine evaporite rocksrdquo in Proceedings of the Pre-sented in the Sixth International Symposium on Salt vol 1 pp267ndash284 Toronto Canada 1983
[76] W Schreyer and K Abraham ldquoThree-stage metamorphic his-tory of a whiteschist from Sar e Sang Afghanistan as part ofa former evaporite depositrdquo Contributions to Mineralogy andPetrology vol 59 no 2 pp 111ndash130 1976
[77] T Angerer and S G Hagemann ldquoThe BIF-hosted high-gradeiron ore deposits in the archean koolyanobbing greenstonebelt Western Australia structural control on synorogenic-and weathering-related magnetite- hematite- and goethite-rich iron orerdquo Economic Geology vol 105 no 5 pp 917ndash9452010
[78] P Duuring and S Hagemann ldquoLeaching of silica bands andconcentration of magnetite in Archean BIF by hypogene fluidsBeebyn Fe ore deposit Yilgarn Craton Western AustraliardquoMineralium Deposita vol 48 no 3 pp 341ndash370 2013
[79] D Shin and I Lee ldquoFluid inclusions and their stable isotopegeochemistry of the carbonate-hosted talc deposits near theCretaceous Muamsa Granite South Koreardquo Geochemical Jour-nal vol 40 no 1 pp 69ndash85 2006
[80] P G Novgorodov ldquoSolubility of quartz in anH2OndashCO
2mixture
at 700 degrees C and pressures of 3 and 5 kbarsrdquoGeokhimiya pp1484ndash1489 1975
[81] T M Gerlach ldquoChemical characteristics of the volcanic gasesfrom Nyiragongo lava lake and the generation of CH
4-rich
fluid inclusions in alkaline rocksrdquo Journal of Volcanology ampGeothermal Research vol 8 no 2-4 pp 177ndash189 1980
[82] J V Walther and P M Orville ldquoVolatile production and trans-port in regional metamorphismrdquo Contributions to Mineralogyand Petrology vol 79 no 3 pp 252ndash257 1982
[83] W F Giggenbach ldquoThe origin and evolution of fluids inmagmatic-hydrothermal systemsrdquo in Geochemistry of Hydro-thermalOreDeposits H L Barnes Ed pp 737ndash796WileyNewYork NY USA 3 edition 1997
[84] J B Lowenstern ldquoCarbon dioxide in magmas and implicationsfor hydrothermal systemsrdquoMineralium Deposita vol 36 no 6pp 490ndash502 2001
[85] R Kerrich and W S Fyfe ldquoThe gold-carbonate associationsource of CO
2 and CO
2fixation reactions in Archaean lode
depositsrdquo Chemical Geology vol 33 no 1ndash4 pp 265ndash294 1981
[86] P I Nabelek ldquoCalc-silicate reactions and bedding-controlledisotopic exchange in the Notch Peak aureole Utah implicationsfor differential fluid fluxes with metamorphic graderdquo Journal ofMetamorphic Geology vol 20 no 4 pp 429ndash440 2002
[87] P I Nabelek ldquoFluid evolution and kinetics of metamorphicreactions in calc-silicate contact aureoles - From H
2O to CO
2
and backrdquo Geology vol 35 no 10 pp 927ndash930 2007[88] H G Machel ldquoBacterial and thermochemical sulfate reduction
in diagenetic settings - old and new insightsrdquo SedimentaryGeology vol 140 no 1-2 pp 143ndash175 2001
[89] L Stalker P Farrimond and S R Larter ldquoWater as an oxygensource for the production of oxygenated compounds (includingCO2precursors) during kerogen maturationrdquo Organic Geo-
chemistry vol 22 no 3-5 pp 477ndashIN4 1994[90] Z K Shipton J P Evans D Kirschner P T Kolesar A P
Williams and J Heath ldquoAnalysis of CO2leakage through lsquolow-
permeabilityrsquo faults from natural reservoirs in the ColoradoPlateau east-central Utahrdquo Geological Society Special Publica-tion vol 233 pp 43ndash58 2004
[91] J Byerlee ldquoFriction overpressure and fault normal compres-sionrdquo Geophysical Research Letters vol 17 no 12 pp 2109ndash21121990
[92] C Morrow B Radney and J Byerlee ldquoChapter 3 frictionalstrength and the effective pressure law of montmorillonite andlllite claysrdquo International Geophysics vol 51 no C pp 69ndash881992
[93] C A Morrow D E Moore and D A Lockner ldquoThe effectof mineral bond strength and adsorbed water on fault gougefrictional strengthrdquo Geophysical Research Letters vol 27 no 6pp 815ndash818 2000
[94] D A Lockner C Morrow D Moore and S Hickman ldquoLowstrength of deep San Andreas fault gouge from SAFOD corerdquoNature vol 472 no 7341 pp 82ndash86 2011
[95] D EMoore andM J Rymer ldquoTalc-bearing serpentinite and thecreeping section of the San Andreas faultrdquo Nature vol 448 no7155 pp 795ndash797 2007
[96] DH Zenger ldquoDiscussion lsquoOn the formation and occurrence ofsaddle dolomitersquordquo Journal of Sedimentary Petrology vol 51 no4 pp 1350ndash1352 1981
[97] DAKatzG P Eberli P K Swart andL B Smith Jr ldquoTectonic-hydrothermal brecciation associated with calcite precipitationand permeability destruction in Mississippian carbonate reser-voirs Montana and Wyomingrdquo AAPG Bulletin vol 90 no 11pp 1803ndash1841 2006
[98] M Esteban and C Taberner ldquoSecondary porosity developmentduring late burial in carbonate reservoirs as a result of mixingandor cooling of brinesrdquo Journal of Geochemical Explorationvol 78-79 pp 355ndash359 2003
[99] H G MacHel ldquoInvestigations of burial diagenesis in carbonatehydrocarbon reservoir rocksrdquoGeoscience Canada vol 32 no 3pp 103ndash128 2005
[100] J A Sagan and B S Hart ldquoThree-dimensional seismic-baseddefinition of fault-related porosity development Trenton-BlackRiver interval Saybrook Ohiordquo AAPG Bulletin vol 90 no 11pp 1763ndash1785 2006
[101] F Xing and S Li ldquoGenesis and environment characteristics ofdolomite-hosted quartz and its significance for hydrocarbonexploration in Keping Area Tarim Basin Chinardquo Journal ofEarth Science vol 23 no 4 pp 476ndash489 2012
[102] L Yun and Z Cao ldquoHydrocarbon enrichment pattern andexploration potential of the Ordovician in Shunnan area TarimBasinrdquo Oil and Gas Geology vol 35 no 6 pp 788ndash797 2014
14 Geofluids
[103] Y Li N Ye X Yuan Q Huang B Su and R Zhou ldquoGeologicaland geochemical characteristics of silicified hydrothermal fluidsin Well Shunnan 4 Tarim Basinrdquo Oil and Gas Geology vol 36no 6 pp 934ndash944 2015
[104] L Qi ldquoOil and gas breakthrough in ultra-deep Ordoviciancarbonate formations in Shuntuoguole uplift Tarim BasinrdquoChina Petroleum Exploration vol 21 no 3 pp 38ndash51 2016 (inChinese with English abstract)
[105] H R Qing ldquoAn introduction of petrology and diagenesis ofultra-deep water carbonate reservoirs from the Atlantic Oceanoffshore Brazilrdquo 2017 Oral presentation at Wuxi Institute ofPetroleum Geology of SINOPEC Wuxi China
[106] G J Simandl and S Paradisl ldquoCarbonate-hosted talcrdquo SelectedBritish ColumbiaMineral Deposit Profiles vol 3 pp 35ndash38 1999
[107] Y K Kharaka D R Cole S D Hovorka W D Gunter K GKnauss and BM Freifeld ldquoGas-water-rock interactions in FrioFormation following CO
2injection implications for the storage
of greenhouse gases in sedimentary basinsrdquoGeology vol 34 no7 pp 577ndash580 2006
[108] Z Duan and D Li ldquoCoupled phase and aqueous speciesequilibrium of the H
2OndashCO
2ndashNaClndashCaCO
3system from 0 to
250∘C 1 to 1000 bar with NaCl concentrations up to saturationof haliterdquo Geochimica et Cosmochimica Acta vol 72 no 20 pp5128ndash5145 2008
[109] M R Giles and J DMarshall ldquoConstraints on the developmentof secondary porosity in the subsurface re-evaluation of pro-cessesrdquoMarine and PetroleumGeology vol 3 no 3 pp 243ndash2551986
[110] O S Pokrovsky S V Golubev and J Schott ldquoDissolution kinet-ics of calcite dolomite and magnesite at 25∘C and 0 to 50 atmpCO2rdquo Chemical Geology vol 217 no 3-4 pp 239ndash255 2005
[111] P Cao Z T Karpyn and L Li ldquoThe role of host rock pro-perties in determining potential CO
2migration pathwaysrdquo
International Journal of Greenhouse Gas Control vol 45 pp 18ndash26 2016
[112] M D Fishburn ldquoSignificant results of deep drilling at ElkHills Kern County Californiardquo in Structure Stratigraphy andHydrocarbon Occurrences of the San Joaquin Basin CaliforniaG K Kuespert and S A Reid Eds vol 64 pp 157ndash167 PacificSections Society of Economic Paleontologists and Mineralo-gists and American Association of Petroleum Geologists 1990
[113] E Povoden M Horacek and R Abart ldquoContact metamor-phism of siliceous dolomite and impure limestones from theWerfen formation in the eastern Monzoni contact aureolerdquoMineralogy and Petrology vol 76 no 1-2 pp 99ndash120 2002
[114] S Yuan I-M Chou R C Burruss X Wang and J Li ldquoDispro-portionation and thermochemical sulfate reduction reactions inSndashH2OndashCH
4and SndashD
2OndashCH
4systems from 200 to 340∘C at
elevated pressuresrdquo Geochimica et Cosmochimica Acta vol 118pp 263ndash275 2013
[115] X Wang I-M Chou W Hu and R C Burruss ldquoIn situ obser-vations of liquid-liquid phase separation in aqueous MgSO
4
solutions geological and geochemical implicationsrdquo Geochim-ica et Cosmochimica Acta vol 103 pp 1ndash10 2013
[116] X Wang Y Wan W Hu et al ldquoIn situ observations of liquid-liquid phase separation in aqueous ZnSO
4solutions at tem-
peratures up to 400∘C Implications for Zn2+ndashSO2minus4
[117] X Wang IM Chou W Hu Y Wan and Z Li ldquoPropertiesof lithium under hydrothermal conditions revealed by in situ
Raman spectroscopic characterization of Li2O-SO
3-H2O(D2O)
systems at temperatures up to 420∘Crdquo Chemical Geology vol451 pp 104ndash115 2017
[118] L Shang I-M Chou W Lu R C Burruss and Y ZhangldquoDetermination of diffusion coefficients of hydrogen in fusedsilica between 296 and 523 K by Raman spectroscopy and appli-cation of fused silica capillaries in studying redox reactionsrdquoGeochimica et CosmochimicaActa vol 73 no 18 pp 5435ndash54432009
[119] M Dargent J Dubessy L Truche E F Bazarkina C Nguyen-Trung and P Robert ldquoExperimental study of uranyl(VI) chlo-ride complex formation in acidic LiCl aqueous solutions underhydrothermal conditions (T = 21∘Cndash350∘C Psat) using Ramanspectroscopyrdquo European Journal ofMineralogy vol 25 no 5 pp765ndash775 2013
[120] YWanXWangWHu and I-MChou ldquoRaman spectroscopicobservations of the ion association between Mg2+ and SO2minus
4
in MgSO4-saturated droplets at temperatures of le380∘Crdquo The
Journal of Physical Chemistry A vol 119 no 34 pp 9027ndash90362015
[121] Y Wan X Wang W Hu I M Chou Y Chen and Z Xu ldquoInsitu optical and Raman spectroscopic observations of the effectsof pressure and fluid composition on liquidliquid phase separa-tion in aqueous cadmium sulfate solutions (=400∘C 50MPa)with geological and geochemical implicationsrdquo Geochimica etCosmochimica Acta vol 211 pp 133ndash152 2017
[122] W L Marshall ldquoAmorphous silica solubilitiesmdashI Behavior inaqueous sodium nitrate solutions 25ndash300∘C 0ndash6 molalrdquo Geo-chimica et Cosmochimica Acta vol 44 no 7 pp 907ndash913 1980
[123] C-T A Chen andW LMarshall ldquoAmorphous silica solubilitiesIV Behavior in pure water and aqueous sodium chloridesodium sulfate magnesium chloride and magnesium sulfatesolutions up to 350∘Crdquo Geochimica et Cosmochimica Acta vol46 no 2 pp 279ndash287 1982
[124] B A Fleming and D A Crerar ldquoSilicic acid ionization and cal-culation of silica solubility at elevated temperature and pHapplication to geothermal fluid processing and reinjectionrdquoGeothermics vol 11 no 1 pp 15ndash29 1982
[6] W Heinrich S S Churakov andM Gottschalk ldquoMineral-fluidequilibria in the system CaOndashMgOndashSiO
2ndashH2OndashCO
2ndashNaCl
and the record of reactive fluid flow in contact metamorphicaureolesrdquo Contributions to Mineralogy and Petrology vol 148no 2 pp 131ndash149 2004
[7] M Wesołowski ldquoThermal decomposition of talc a reviewrdquoThermochimica Acta vol 78 no 1-3 pp 395ndash421 1984
[8] L A Perez-Maqueda A Duran and J L Perez-RodrıguezldquoPreparation of submicron talc particles by sonicationrdquoAppliedClay Science vol 28 no 1-4 pp 245ndash255 2005
[9] R L Johnson ldquoTalcrdquoAmerican Ceramic Society Bulletin vol 71pp 818ndash820 1992
[10] R L Johnson and R L Virta ldquoTalcrdquo American Ceramic SocietyBulletin vol 79 pp 79ndash81 2000
[11] M Z Abzalov ldquoChrome-spinels in gabbro-wehrlite intrusionsof the Pechenga area Kola Peninsula Russia emphasis onalteration featuresrdquo Lithos vol 43 no 3 pp 109ndash134 1998
[12] M F El-Sharkawy ldquoTalc mineralization of ultramafic affinity inthe Eastern Desert of Egyptrdquo Mineralium Deposita vol 35 no4 pp 346ndash363 2000
[13] M Franceschelli G Carcangiu A M Caredda G CrucianiI Memmi and M Zucca ldquoTransformation of cumulate maficrocks to granulite and re-equilibration in amphibolite andgreenschist facies in NE Sardinia Italyrdquo Lithos vol 63 no 1-2pp 1ndash18 2002
[14] S G Tesalina P Nimis T Auge and V V Zaykov ldquoOriginof chromite in mafic-ultramafic-hosted hydrothermal massivesulfides from the Main Uralian Fault South Urals RussiardquoLithos vol 70 no 1-2 pp 39ndash59 2003
[15] D M Evans ldquoMetamorphic modifications of the Muremeramafic-ultramafic intrusions eastern Burundi and their effecton chromite compositionsrdquo Journal of African Earth Sciencesvol 101 pp 19ndash34 2015
[16] T Yamanaka K Maeto H Akashi et al ldquoShallow submarinehydrothermal activity with significant contribution of mag-matic water producing talc chimneys in the Wakamiko CraterofKagoshimaBay southernKyushu Japanrdquo Journal of Volcanol-ogy and Geothermal Research vol 258 pp 74ndash84 2013
[17] B Moine J P Fortune P Moreau and F Viguier ldquoComparativemineralogy geochemistry and conditions of formation of twometasomatic talc and chlorite deposits Trimouns PyreneesFrance and Rabenwald eastern Alps Austriardquo Economic Geol-ogy vol 84 no 5 pp 1398ndash1416 1989
[18] W Prochaska ldquoGeochemistry and genesis of Austrian talcdepositsrdquo Applied Geochemistry vol 4 no 5 pp 511ndash525 1989
[19] P de Parseval S Jiang F Fontan R Wang F Martin and JFreeet ldquoGeology and ore genesis of the Trimouns talc-chloriteore deposit Pyrenees Francerdquo Acta Petrologica Sinica vol 20no 4 pp 877ndash886 2004
[20] A C Gondim and S Jiang ldquoGeologic characteristics and gene-ticmodels for the talc deposits in Parana andBahia BrazilrdquoActaPetrologica Sinica vol 20 no 4 pp 829ndash836 2004
[21] P Boulvais P de Parseval A DrsquoHulst and P Paris ldquoCarbonatealteration associated with talc-chlorite mineralization in theeastern Pyrenees with emphasis on the St Barthelemy MassifrdquoMineralogy and Petrology vol 88 no 3-4 pp 499ndash526 2006
[22] G R Davies and L B Smith Jr ldquoStructurally controlled hydro-thermal dolomite reservoir facies an overviewrdquoAAPG Bulletinvol 90 no 11 pp 1641ndash1690 2006
[23] J Lonnee and H G Machel ldquoPervasive dolomitization withsubsequent hydrothermal alteration in theClarke Lake gas field
Middle Devonian Slave Point Formation British ColumbiaCanadardquo AAPG Bulletin vol 90 no 11 pp 1739ndash1761 2006
[24] J A Luczaj ldquoEvidence against the Dorag (mixing-zone) modelfor dolomitization along theWisconsin arch - A case for hydro-thermal diagenesisrdquo AAPG Bulletin vol 90 no 11 pp 1719ndash1738 2006
[25] L B Smith Jr ldquoOrigin and reservoir characteristics of UpperOrdovician Trenton-Black River hydrothermal dolomite reser-voirs in New YorkrdquoAAPG Bulletin vol 90 no 11 pp 1691ndash17182006
[26] J Parnell ldquoDevonianMagadi-type cherts in theOrcadian BasinScotlandrdquo Journal of Sedimentary Petrology vol 56 no 4 pp495ndash500 1986
[27] J M Garcıa-Ruiz ldquoCarbonate precipitation into alkaline silica-rich environmentsrdquo Geology vol 26 no 9 pp 843ndash846 1998
[28] J Zhang W Hu Y Qian et al ldquoFormation of saddle dolomitesin Upper Cambrian carbonates western Tarim Basin (north-west China) implications for fault-related fluid flowrdquo Marineand Petroleum Geology vol 26 no 8 pp 1428ndash1440 2009
[29] J M McKinley R H Worden and A H Ruffell ldquoContactdiagenesis the effect of an intrusion on reservoir quality in thetriassic sherwood sandstone group Northern Irelandrdquo Journalof Sedimentary Research vol 71 no 3 pp 484ndash495 2001
[30] S Dong D Chen H Qing et al ldquoHydrothermal alteration ofdolostones in the Lower Ordovician Tarim Basin NW Chinamultiple constraints from petrology isotope geochemistry andfluid inclusion microthermometryrdquo Marine and PetroleumGeology vol 46 pp 270ndash286 2013
[31] V Madrucci C W D D Anjos R A Spadini D B Alvesand S M C Anjos ldquoAuthigenic magnesian clays in carbonatereservoirs in Brazilrdquo in Proceedings of the 15th International ClayConference Rio De Janeiro Brazil 2013
[32] C H Scholz ldquoEarthquakes and friction lawsrdquo Nature vol 391no 6662 pp 37ndash42 1998
[33] A M Schleicher B A Van Der Pluijm J G Solum andL N Warr ldquoOrigin and significance of clay-coated fracturesin mudrock fragments of the SAFOD borehole (ParkfieldCalifornia)rdquoGeophysical Research Letters vol 33 no 16 ArticleID L16313 2006
[34] A M Schleicher B A van der Pluijm and L N Warr ldquoNano-coatings of clay and creep of the San Andreas fault at ParkfieldCaliforniardquo Geology vol 38 no 7 pp 667ndash670 2010
[35] C Collettini C Viti S A F Smith and R E HoldsworthldquoDevelopment of interconnected talc networks and weakeningof continental low-angle normal faultsrdquo Geology vol 37 no 6pp 567ndash570 2009
[36] F Tornos and B F Spiro ldquoThe geology and isotope geochem-istry of the talc deposits of Puebla de Lillo (Cantabrian zonenorthern Spain)rdquo Economic Geology vol 95 no 6 pp 1277ndash1296 2000
[37] L Hecht R Freiberger H A Gilg G Grundmann and Y AKostitsyn ldquoRare earth element and isotope (C O Sr) charac-teristics of hydrothermal carbonates genetic implications fordolomite-hosted talc mineralization at Gopfersgrun (Fichtelge-birge Germany)rdquo Chemical Geology vol 155 no 1-2 pp 115ndash130 1999
[38] R Sharma P Joshi and P D Pant ldquoThe role of fluids inthe formation of talc deposits of Rema area Kumaun LesserHimalayardquo Journal of the Geological Society of India vol 73 no2 pp 237ndash248 2009
12 Geofluids
[39] P De Parseval B Moine J P Fortune and J Ferret ldquoFluid-mineral interactions at the origin of the Trimouns talc andchlorite deposit (Pyrenees France)rdquo in Current Research inGeology Applied to Ore Deposits P Fenoll Hach-Ali J Torrez-Ruiz and F Gervilla Eds pp 205ndash209 University of GranadaGranada Granada Spain 1993
[40] M C Boiron P Boulvais M Cathelineau D Banks N Cal-vayrac and G Hubert ldquoFluid circulation at the origin of thetrimouns talc deposit (Pyrenees France)rdquo in Proceedings of the18th Meeting of European Current Research on Fluid InclusionsSiena Italy 2005
[41] P Bayliss andA A Levhinson ldquoLow temperature hydrothermalsynthesis from dolomite or calcite quartz and kaoliniterdquo Claysand Clay Minerals vol 19 no 2 pp 109ndash114 1971
[42] G Skippen ldquoAn experimental model for low pressure meta-morphism of siliceous dolomitic marblerdquo American Journal ofScience vol 274 no 5 pp 487ndash509 1974
[43] J Slaughter D M Kerrick and V J Wall ldquoExperimen-tal and thermodynamic study of equilibria in the systemCaOndashMgOndashSiO
2ndashH2OndashCO
2rdquoAmerican Journal of Science vol
275 pp 143ndash162 1975[44] R G Eggert and D M Kerrick ldquoMetamorphic equilibria in the
siliceous dolomite system 6 kbar experimental data and geo-logic implicationsrdquo Geochimica et Cosmochimica Acta vol 45no 7 pp 1039ndash1049 1981
[45] Z Zhang and Z Duan ldquoPrediction of the PVT properties ofwater over wide range of temperatures and pressures frommolecular dynamics simulationrdquo Physics of the Earth andPlanetary Interiors vol 149 no 3-4 pp 335ndash354 2005
[46] I-M Chou Y Song and R C Burruss ldquoA newmethod for syn-thesizing fluid inclusions in fused silica capillaries containingorganic and inorganic materialrdquo Geochimica et CosmochimicaActa vol 72 no 21 pp 5217ndash5231 2008
[47] I-M Chou R C Burruss and W J Lu ldquoA new optical cellfor spectroscopic studies of geologic fluids at pressures up to100MPardquo in Advances in High-Pressure Technology for Geo-physical Applications J Chen YWang T S Duffy G Shen andL F Dobrzhinetakaya Eds pp 475ndash485 Elsevier AmsterdamNetherlands 2005
[48] K M Rosso and R J Bodnar ldquoMicrothermometric and Ramanspectroscopic detection limits of CO
2in fluid inclusions and the
Raman spectroscopic characterization of CO2rdquo Geochimica et
Cosmochimica Acta vol 59 no 19 pp 3961ndash3975 1995[49] H M Lamadrid Geochemistry of fluid-rock processes [Doctoral
dissertation] Virginia Polytechnic Institute and State Univer-sity Blacksburg VA USA 2016
[50] J H Parker D W Feldman and M Ashkin ldquoRaman scatteringby silicon and germaniumrdquo Physical Review vol 155 no 3 pp712ndash714 1967
[51] Y V Shvarov ldquoAlgorithmization of the numeric equilibriummodeling of dynamic geochemical processesrdquo GeochemistryInternational vol 37 no 6 pp 571ndash576 1999
[52] R B Wright and C H Wang ldquoDensity effect on the Fermiresonance in gaseous CO
2by Raman scatteringrdquoThe Journal of
Chemical Physics vol 58 no 7 pp 2893ndash2895 1973[53] XWang I-M ChouWHu R C Burruss Q Sun and Y Song
ldquoRaman spectroscopic measurements of CO2density experi-
mental calibration with high-pressure optical cell (HPOC) andfused silica capillary capsule (FSCC) with application to fluidinclusion observationsrdquo Geochimica et Cosmochimica Acta vol75 no 14 pp 4080ndash4093 2011
[54] H R Gordon and T K McCubbin Jr ldquoThe 28-micron bandsof CO
2rdquo Journal of Molecular Spectroscopy vol 19 no 1ndash4 pp
137ndash154 1966[55] T Azbej M J Severs B G Rusk and R J Bodnar ldquoIn situ
quantitative analysis of individual H2O-CO
2fluid inclusions by
laser Raman spectroscopyrdquo Chemical Geology vol 237 no 3-4pp 255ndash263 2007
[56] Y Song I M Chou W Hu B Robert and W Lu ldquoCO2
density-raman shift relation derived from synthetic inclusionsin fused silica capillaries and its applicationrdquo Acta GeologicaSinica (English Edition) vol 83 pp 932ndash938 2009
[57] Z Pan I-M Chou and R C Burruss ldquoHydrolysis of polycar-bonate in sub-critical water in fused silica capillary reactor within situ Raman spectroscopyrdquo Green Chemistry vol 11 no 8 pp1105ndash1107 2009
[58] M L Frezzotti F Tecce and A Casagli ldquoRaman spectroscopyfor fluid inclusion analysisrdquo Journal of Geochemical Explorationvol 112 pp 1ndash20 2012
[59] E L Shock and H C Helgeson ldquoCalculation of the thermo-dynamic and transport properties of aqueous species at highpressures and temperatures correlation algorithms for ionicspecies and equation of state predictions to 5 kb and 1000∘CrdquoGeochimica et Cosmochimica Acta vol 52 no 8 pp 2009ndash20361988
[60] O S Pokrovsky SVGolubev J Schott andACastillo ldquoCalcitedolomite and magnesite dissolution kinetics in aqueous solu-tions at acid to circumneutral pH 25 to 150∘C and 1 to 55 atmpCO2 New constraints on CO
2sequestration in sedimentary
basinsrdquo Chemical Geology vol 265 no 1-2 pp 20ndash32 2009[61] YGarrabos R Tufeu B LeNeindre G Zalczer andD Beysens
ldquoRayleigh andRaman scattering near the critical point of carbondioxiderdquo The Journal of Chemical Physics vol 72 no 8 pp4637ndash4651 1979
[62] J H Nicola J F Scott R M Couto andMM Correa ldquoRamanspectra of dolomite [CaMg(CO
3)2]rdquo Physical Review B vol 14
no 10 pp 4676ndash4678 1976[63] S Gunasekaran G Anbalagan and S Pandi ldquoRaman and
infrared spectra of carbonates of calcite structurerdquo Journal ofRaman Spectroscopy vol 37 no 9 pp 892ndash899 2006
[64] G J Rosasco and J J Blaha ldquoRaman microprobe spectra andvibrationalmode assignments of talcrdquoApplied Spectroscopy vol34 no 2 pp 140ndash144 1980
[65] V Trommsdorff and B W Evans ldquoAntigorite-ophicarbo-nates phase relations in a portion of the system CaOndashMgOndashSiO2ndashH2OndashCO
2rdquo Contributions to Mineralogy and Petrology
vol 60 no 1 pp 39ndash56 1977[66] V Trommsdorff and J A D Connolly ldquoConstraints on phase
diagram topology for the systemCaOndashMgOndashSiO2ndashCO2ndashH2Ordquo
Contributions to Mineralogy and Petrology vol 104 no 1 pp 1ndash7 1990
[67] B S Van Gosen H A Lowers S J Sutley and C A GentldquoUsing the geologic setting of talc deposits as an indicator ofamphibole asbestos contentrdquo Environmental Geology vol 45no 7 pp 920ndash939 2004
[68] W Johannes ldquoAn experimental investigation of the systemMgO-SiO
2-H2O-CO
2rdquo American Journal of Science vol 267
no 9 pp 1083ndash1104 1969[69] E S Schandl and M P Gorton ldquoHydrothermal alteration and
CO2metasomatism (natural carbon sequestration) of komati-
ites in the south-western Abitibi greenstone beltrdquo CanadianMineralogist vol 50 no 1 pp 129ndash146 2012
Geofluids 13
[70] B W Evans and S Guggenheim ldquoTalc phyrophyllite andrelated mineralsrdquo in Reviews in Mineralogy S W Bailey Edvol 19 pp 225ndash294 1988
[71] B Velde ldquoExperimental pseudomorphism of diopside by talcand serpentine in (Ni Mg)Cl
2aqueous solutionsrdquo Geochimica
et Cosmochimica Acta vol 52 no 2 pp 415ndash424 1988[72] A E Williams-Jones C Normand H Clark Vali Jr R F
Martin A Dufresne and Nayebzadeh A ldquoControls of amphi-bole formation in chrysotile from the Jeffrey Mine AsbestosQuebecrdquo inTheHealth Effects Effects of Chrysotile Asbestos R PNolan AM LangerM RossWicks F J andMartin F R Edsvol 5 pp 89ndash104 The Mineralogical Association of CanadaQuebec Quebec Canada 2001
[73] B W Evans ldquoThe serpentinite multisystem revisited chrysotileis metastablerdquo International Geology Review vol 46 no 6 pp479ndash506 2004
[74] I Gunnarsson and S Arnorsson ldquoAmorphous silica solubilityand the thermodynamic properties of H
4SiO∘4in the range of
0∘ to 350∘C at Psatrdquo Geochimica et Cosmochimica Acta vol 64no 13 pp 2295ndash2307 2000
[75] M W Bodine Jr ldquoTrioctahedral clay mineral assemblages inPaleozoic marine evaporite rocksrdquo in Proceedings of the Pre-sented in the Sixth International Symposium on Salt vol 1 pp267ndash284 Toronto Canada 1983
[76] W Schreyer and K Abraham ldquoThree-stage metamorphic his-tory of a whiteschist from Sar e Sang Afghanistan as part ofa former evaporite depositrdquo Contributions to Mineralogy andPetrology vol 59 no 2 pp 111ndash130 1976
[77] T Angerer and S G Hagemann ldquoThe BIF-hosted high-gradeiron ore deposits in the archean koolyanobbing greenstonebelt Western Australia structural control on synorogenic-and weathering-related magnetite- hematite- and goethite-rich iron orerdquo Economic Geology vol 105 no 5 pp 917ndash9452010
[78] P Duuring and S Hagemann ldquoLeaching of silica bands andconcentration of magnetite in Archean BIF by hypogene fluidsBeebyn Fe ore deposit Yilgarn Craton Western AustraliardquoMineralium Deposita vol 48 no 3 pp 341ndash370 2013
[79] D Shin and I Lee ldquoFluid inclusions and their stable isotopegeochemistry of the carbonate-hosted talc deposits near theCretaceous Muamsa Granite South Koreardquo Geochemical Jour-nal vol 40 no 1 pp 69ndash85 2006
[80] P G Novgorodov ldquoSolubility of quartz in anH2OndashCO
2mixture
at 700 degrees C and pressures of 3 and 5 kbarsrdquoGeokhimiya pp1484ndash1489 1975
[81] T M Gerlach ldquoChemical characteristics of the volcanic gasesfrom Nyiragongo lava lake and the generation of CH
4-rich
fluid inclusions in alkaline rocksrdquo Journal of Volcanology ampGeothermal Research vol 8 no 2-4 pp 177ndash189 1980
[82] J V Walther and P M Orville ldquoVolatile production and trans-port in regional metamorphismrdquo Contributions to Mineralogyand Petrology vol 79 no 3 pp 252ndash257 1982
[83] W F Giggenbach ldquoThe origin and evolution of fluids inmagmatic-hydrothermal systemsrdquo in Geochemistry of Hydro-thermalOreDeposits H L Barnes Ed pp 737ndash796WileyNewYork NY USA 3 edition 1997
[84] J B Lowenstern ldquoCarbon dioxide in magmas and implicationsfor hydrothermal systemsrdquoMineralium Deposita vol 36 no 6pp 490ndash502 2001
[85] R Kerrich and W S Fyfe ldquoThe gold-carbonate associationsource of CO
2 and CO
2fixation reactions in Archaean lode
depositsrdquo Chemical Geology vol 33 no 1ndash4 pp 265ndash294 1981
[86] P I Nabelek ldquoCalc-silicate reactions and bedding-controlledisotopic exchange in the Notch Peak aureole Utah implicationsfor differential fluid fluxes with metamorphic graderdquo Journal ofMetamorphic Geology vol 20 no 4 pp 429ndash440 2002
[87] P I Nabelek ldquoFluid evolution and kinetics of metamorphicreactions in calc-silicate contact aureoles - From H
2O to CO
2
and backrdquo Geology vol 35 no 10 pp 927ndash930 2007[88] H G Machel ldquoBacterial and thermochemical sulfate reduction
in diagenetic settings - old and new insightsrdquo SedimentaryGeology vol 140 no 1-2 pp 143ndash175 2001
[89] L Stalker P Farrimond and S R Larter ldquoWater as an oxygensource for the production of oxygenated compounds (includingCO2precursors) during kerogen maturationrdquo Organic Geo-
chemistry vol 22 no 3-5 pp 477ndashIN4 1994[90] Z K Shipton J P Evans D Kirschner P T Kolesar A P
Williams and J Heath ldquoAnalysis of CO2leakage through lsquolow-
permeabilityrsquo faults from natural reservoirs in the ColoradoPlateau east-central Utahrdquo Geological Society Special Publica-tion vol 233 pp 43ndash58 2004
[91] J Byerlee ldquoFriction overpressure and fault normal compres-sionrdquo Geophysical Research Letters vol 17 no 12 pp 2109ndash21121990
[92] C Morrow B Radney and J Byerlee ldquoChapter 3 frictionalstrength and the effective pressure law of montmorillonite andlllite claysrdquo International Geophysics vol 51 no C pp 69ndash881992
[93] C A Morrow D E Moore and D A Lockner ldquoThe effectof mineral bond strength and adsorbed water on fault gougefrictional strengthrdquo Geophysical Research Letters vol 27 no 6pp 815ndash818 2000
[94] D A Lockner C Morrow D Moore and S Hickman ldquoLowstrength of deep San Andreas fault gouge from SAFOD corerdquoNature vol 472 no 7341 pp 82ndash86 2011
[95] D EMoore andM J Rymer ldquoTalc-bearing serpentinite and thecreeping section of the San Andreas faultrdquo Nature vol 448 no7155 pp 795ndash797 2007
[96] DH Zenger ldquoDiscussion lsquoOn the formation and occurrence ofsaddle dolomitersquordquo Journal of Sedimentary Petrology vol 51 no4 pp 1350ndash1352 1981
[97] DAKatzG P Eberli P K Swart andL B Smith Jr ldquoTectonic-hydrothermal brecciation associated with calcite precipitationand permeability destruction in Mississippian carbonate reser-voirs Montana and Wyomingrdquo AAPG Bulletin vol 90 no 11pp 1803ndash1841 2006
[98] M Esteban and C Taberner ldquoSecondary porosity developmentduring late burial in carbonate reservoirs as a result of mixingandor cooling of brinesrdquo Journal of Geochemical Explorationvol 78-79 pp 355ndash359 2003
[99] H G MacHel ldquoInvestigations of burial diagenesis in carbonatehydrocarbon reservoir rocksrdquoGeoscience Canada vol 32 no 3pp 103ndash128 2005
[100] J A Sagan and B S Hart ldquoThree-dimensional seismic-baseddefinition of fault-related porosity development Trenton-BlackRiver interval Saybrook Ohiordquo AAPG Bulletin vol 90 no 11pp 1763ndash1785 2006
[101] F Xing and S Li ldquoGenesis and environment characteristics ofdolomite-hosted quartz and its significance for hydrocarbonexploration in Keping Area Tarim Basin Chinardquo Journal ofEarth Science vol 23 no 4 pp 476ndash489 2012
[102] L Yun and Z Cao ldquoHydrocarbon enrichment pattern andexploration potential of the Ordovician in Shunnan area TarimBasinrdquo Oil and Gas Geology vol 35 no 6 pp 788ndash797 2014
14 Geofluids
[103] Y Li N Ye X Yuan Q Huang B Su and R Zhou ldquoGeologicaland geochemical characteristics of silicified hydrothermal fluidsin Well Shunnan 4 Tarim Basinrdquo Oil and Gas Geology vol 36no 6 pp 934ndash944 2015
[104] L Qi ldquoOil and gas breakthrough in ultra-deep Ordoviciancarbonate formations in Shuntuoguole uplift Tarim BasinrdquoChina Petroleum Exploration vol 21 no 3 pp 38ndash51 2016 (inChinese with English abstract)
[105] H R Qing ldquoAn introduction of petrology and diagenesis ofultra-deep water carbonate reservoirs from the Atlantic Oceanoffshore Brazilrdquo 2017 Oral presentation at Wuxi Institute ofPetroleum Geology of SINOPEC Wuxi China
[106] G J Simandl and S Paradisl ldquoCarbonate-hosted talcrdquo SelectedBritish ColumbiaMineral Deposit Profiles vol 3 pp 35ndash38 1999
[107] Y K Kharaka D R Cole S D Hovorka W D Gunter K GKnauss and BM Freifeld ldquoGas-water-rock interactions in FrioFormation following CO
2injection implications for the storage
of greenhouse gases in sedimentary basinsrdquoGeology vol 34 no7 pp 577ndash580 2006
[108] Z Duan and D Li ldquoCoupled phase and aqueous speciesequilibrium of the H
2OndashCO
2ndashNaClndashCaCO
3system from 0 to
250∘C 1 to 1000 bar with NaCl concentrations up to saturationof haliterdquo Geochimica et Cosmochimica Acta vol 72 no 20 pp5128ndash5145 2008
[109] M R Giles and J DMarshall ldquoConstraints on the developmentof secondary porosity in the subsurface re-evaluation of pro-cessesrdquoMarine and PetroleumGeology vol 3 no 3 pp 243ndash2551986
[110] O S Pokrovsky S V Golubev and J Schott ldquoDissolution kinet-ics of calcite dolomite and magnesite at 25∘C and 0 to 50 atmpCO2rdquo Chemical Geology vol 217 no 3-4 pp 239ndash255 2005
[111] P Cao Z T Karpyn and L Li ldquoThe role of host rock pro-perties in determining potential CO
2migration pathwaysrdquo
International Journal of Greenhouse Gas Control vol 45 pp 18ndash26 2016
[112] M D Fishburn ldquoSignificant results of deep drilling at ElkHills Kern County Californiardquo in Structure Stratigraphy andHydrocarbon Occurrences of the San Joaquin Basin CaliforniaG K Kuespert and S A Reid Eds vol 64 pp 157ndash167 PacificSections Society of Economic Paleontologists and Mineralo-gists and American Association of Petroleum Geologists 1990
[113] E Povoden M Horacek and R Abart ldquoContact metamor-phism of siliceous dolomite and impure limestones from theWerfen formation in the eastern Monzoni contact aureolerdquoMineralogy and Petrology vol 76 no 1-2 pp 99ndash120 2002
[114] S Yuan I-M Chou R C Burruss X Wang and J Li ldquoDispro-portionation and thermochemical sulfate reduction reactions inSndashH2OndashCH
4and SndashD
2OndashCH
4systems from 200 to 340∘C at
elevated pressuresrdquo Geochimica et Cosmochimica Acta vol 118pp 263ndash275 2013
[115] X Wang I-M Chou W Hu and R C Burruss ldquoIn situ obser-vations of liquid-liquid phase separation in aqueous MgSO
4
solutions geological and geochemical implicationsrdquo Geochim-ica et Cosmochimica Acta vol 103 pp 1ndash10 2013
[116] X Wang Y Wan W Hu et al ldquoIn situ observations of liquid-liquid phase separation in aqueous ZnSO
4solutions at tem-
peratures up to 400∘C Implications for Zn2+ndashSO2minus4
[117] X Wang IM Chou W Hu Y Wan and Z Li ldquoPropertiesof lithium under hydrothermal conditions revealed by in situ
Raman spectroscopic characterization of Li2O-SO
3-H2O(D2O)
systems at temperatures up to 420∘Crdquo Chemical Geology vol451 pp 104ndash115 2017
[118] L Shang I-M Chou W Lu R C Burruss and Y ZhangldquoDetermination of diffusion coefficients of hydrogen in fusedsilica between 296 and 523 K by Raman spectroscopy and appli-cation of fused silica capillaries in studying redox reactionsrdquoGeochimica et CosmochimicaActa vol 73 no 18 pp 5435ndash54432009
[119] M Dargent J Dubessy L Truche E F Bazarkina C Nguyen-Trung and P Robert ldquoExperimental study of uranyl(VI) chlo-ride complex formation in acidic LiCl aqueous solutions underhydrothermal conditions (T = 21∘Cndash350∘C Psat) using Ramanspectroscopyrdquo European Journal ofMineralogy vol 25 no 5 pp765ndash775 2013
[120] YWanXWangWHu and I-MChou ldquoRaman spectroscopicobservations of the ion association between Mg2+ and SO2minus
4
in MgSO4-saturated droplets at temperatures of le380∘Crdquo The
Journal of Physical Chemistry A vol 119 no 34 pp 9027ndash90362015
[121] Y Wan X Wang W Hu I M Chou Y Chen and Z Xu ldquoInsitu optical and Raman spectroscopic observations of the effectsof pressure and fluid composition on liquidliquid phase separa-tion in aqueous cadmium sulfate solutions (=400∘C 50MPa)with geological and geochemical implicationsrdquo Geochimica etCosmochimica Acta vol 211 pp 133ndash152 2017
[122] W L Marshall ldquoAmorphous silica solubilitiesmdashI Behavior inaqueous sodium nitrate solutions 25ndash300∘C 0ndash6 molalrdquo Geo-chimica et Cosmochimica Acta vol 44 no 7 pp 907ndash913 1980
[123] C-T A Chen andW LMarshall ldquoAmorphous silica solubilitiesIV Behavior in pure water and aqueous sodium chloridesodium sulfate magnesium chloride and magnesium sulfatesolutions up to 350∘Crdquo Geochimica et Cosmochimica Acta vol46 no 2 pp 279ndash287 1982
[124] B A Fleming and D A Crerar ldquoSilicic acid ionization and cal-culation of silica solubility at elevated temperature and pHapplication to geothermal fluid processing and reinjectionrdquoGeothermics vol 11 no 1 pp 15ndash29 1982
[39] P De Parseval B Moine J P Fortune and J Ferret ldquoFluid-mineral interactions at the origin of the Trimouns talc andchlorite deposit (Pyrenees France)rdquo in Current Research inGeology Applied to Ore Deposits P Fenoll Hach-Ali J Torrez-Ruiz and F Gervilla Eds pp 205ndash209 University of GranadaGranada Granada Spain 1993
[40] M C Boiron P Boulvais M Cathelineau D Banks N Cal-vayrac and G Hubert ldquoFluid circulation at the origin of thetrimouns talc deposit (Pyrenees France)rdquo in Proceedings of the18th Meeting of European Current Research on Fluid InclusionsSiena Italy 2005
[41] P Bayliss andA A Levhinson ldquoLow temperature hydrothermalsynthesis from dolomite or calcite quartz and kaoliniterdquo Claysand Clay Minerals vol 19 no 2 pp 109ndash114 1971
[42] G Skippen ldquoAn experimental model for low pressure meta-morphism of siliceous dolomitic marblerdquo American Journal ofScience vol 274 no 5 pp 487ndash509 1974
[43] J Slaughter D M Kerrick and V J Wall ldquoExperimen-tal and thermodynamic study of equilibria in the systemCaOndashMgOndashSiO
2ndashH2OndashCO
2rdquoAmerican Journal of Science vol
275 pp 143ndash162 1975[44] R G Eggert and D M Kerrick ldquoMetamorphic equilibria in the
siliceous dolomite system 6 kbar experimental data and geo-logic implicationsrdquo Geochimica et Cosmochimica Acta vol 45no 7 pp 1039ndash1049 1981
[45] Z Zhang and Z Duan ldquoPrediction of the PVT properties ofwater over wide range of temperatures and pressures frommolecular dynamics simulationrdquo Physics of the Earth andPlanetary Interiors vol 149 no 3-4 pp 335ndash354 2005
[46] I-M Chou Y Song and R C Burruss ldquoA newmethod for syn-thesizing fluid inclusions in fused silica capillaries containingorganic and inorganic materialrdquo Geochimica et CosmochimicaActa vol 72 no 21 pp 5217ndash5231 2008
[47] I-M Chou R C Burruss and W J Lu ldquoA new optical cellfor spectroscopic studies of geologic fluids at pressures up to100MPardquo in Advances in High-Pressure Technology for Geo-physical Applications J Chen YWang T S Duffy G Shen andL F Dobrzhinetakaya Eds pp 475ndash485 Elsevier AmsterdamNetherlands 2005
[48] K M Rosso and R J Bodnar ldquoMicrothermometric and Ramanspectroscopic detection limits of CO
2in fluid inclusions and the
Raman spectroscopic characterization of CO2rdquo Geochimica et
Cosmochimica Acta vol 59 no 19 pp 3961ndash3975 1995[49] H M Lamadrid Geochemistry of fluid-rock processes [Doctoral
dissertation] Virginia Polytechnic Institute and State Univer-sity Blacksburg VA USA 2016
[50] J H Parker D W Feldman and M Ashkin ldquoRaman scatteringby silicon and germaniumrdquo Physical Review vol 155 no 3 pp712ndash714 1967
[51] Y V Shvarov ldquoAlgorithmization of the numeric equilibriummodeling of dynamic geochemical processesrdquo GeochemistryInternational vol 37 no 6 pp 571ndash576 1999
[52] R B Wright and C H Wang ldquoDensity effect on the Fermiresonance in gaseous CO
2by Raman scatteringrdquoThe Journal of
Chemical Physics vol 58 no 7 pp 2893ndash2895 1973[53] XWang I-M ChouWHu R C Burruss Q Sun and Y Song
ldquoRaman spectroscopic measurements of CO2density experi-
mental calibration with high-pressure optical cell (HPOC) andfused silica capillary capsule (FSCC) with application to fluidinclusion observationsrdquo Geochimica et Cosmochimica Acta vol75 no 14 pp 4080ndash4093 2011
[54] H R Gordon and T K McCubbin Jr ldquoThe 28-micron bandsof CO
2rdquo Journal of Molecular Spectroscopy vol 19 no 1ndash4 pp
137ndash154 1966[55] T Azbej M J Severs B G Rusk and R J Bodnar ldquoIn situ
quantitative analysis of individual H2O-CO
2fluid inclusions by
laser Raman spectroscopyrdquo Chemical Geology vol 237 no 3-4pp 255ndash263 2007
[56] Y Song I M Chou W Hu B Robert and W Lu ldquoCO2
density-raman shift relation derived from synthetic inclusionsin fused silica capillaries and its applicationrdquo Acta GeologicaSinica (English Edition) vol 83 pp 932ndash938 2009
[57] Z Pan I-M Chou and R C Burruss ldquoHydrolysis of polycar-bonate in sub-critical water in fused silica capillary reactor within situ Raman spectroscopyrdquo Green Chemistry vol 11 no 8 pp1105ndash1107 2009
[58] M L Frezzotti F Tecce and A Casagli ldquoRaman spectroscopyfor fluid inclusion analysisrdquo Journal of Geochemical Explorationvol 112 pp 1ndash20 2012
[59] E L Shock and H C Helgeson ldquoCalculation of the thermo-dynamic and transport properties of aqueous species at highpressures and temperatures correlation algorithms for ionicspecies and equation of state predictions to 5 kb and 1000∘CrdquoGeochimica et Cosmochimica Acta vol 52 no 8 pp 2009ndash20361988
[60] O S Pokrovsky SVGolubev J Schott andACastillo ldquoCalcitedolomite and magnesite dissolution kinetics in aqueous solu-tions at acid to circumneutral pH 25 to 150∘C and 1 to 55 atmpCO2 New constraints on CO
2sequestration in sedimentary
basinsrdquo Chemical Geology vol 265 no 1-2 pp 20ndash32 2009[61] YGarrabos R Tufeu B LeNeindre G Zalczer andD Beysens
ldquoRayleigh andRaman scattering near the critical point of carbondioxiderdquo The Journal of Chemical Physics vol 72 no 8 pp4637ndash4651 1979
[62] J H Nicola J F Scott R M Couto andMM Correa ldquoRamanspectra of dolomite [CaMg(CO
3)2]rdquo Physical Review B vol 14
no 10 pp 4676ndash4678 1976[63] S Gunasekaran G Anbalagan and S Pandi ldquoRaman and
infrared spectra of carbonates of calcite structurerdquo Journal ofRaman Spectroscopy vol 37 no 9 pp 892ndash899 2006
[64] G J Rosasco and J J Blaha ldquoRaman microprobe spectra andvibrationalmode assignments of talcrdquoApplied Spectroscopy vol34 no 2 pp 140ndash144 1980
[65] V Trommsdorff and B W Evans ldquoAntigorite-ophicarbo-nates phase relations in a portion of the system CaOndashMgOndashSiO2ndashH2OndashCO
2rdquo Contributions to Mineralogy and Petrology
vol 60 no 1 pp 39ndash56 1977[66] V Trommsdorff and J A D Connolly ldquoConstraints on phase
diagram topology for the systemCaOndashMgOndashSiO2ndashCO2ndashH2Ordquo
Contributions to Mineralogy and Petrology vol 104 no 1 pp 1ndash7 1990
[67] B S Van Gosen H A Lowers S J Sutley and C A GentldquoUsing the geologic setting of talc deposits as an indicator ofamphibole asbestos contentrdquo Environmental Geology vol 45no 7 pp 920ndash939 2004
[68] W Johannes ldquoAn experimental investigation of the systemMgO-SiO
2-H2O-CO
2rdquo American Journal of Science vol 267
no 9 pp 1083ndash1104 1969[69] E S Schandl and M P Gorton ldquoHydrothermal alteration and
CO2metasomatism (natural carbon sequestration) of komati-
ites in the south-western Abitibi greenstone beltrdquo CanadianMineralogist vol 50 no 1 pp 129ndash146 2012
Geofluids 13
[70] B W Evans and S Guggenheim ldquoTalc phyrophyllite andrelated mineralsrdquo in Reviews in Mineralogy S W Bailey Edvol 19 pp 225ndash294 1988
[71] B Velde ldquoExperimental pseudomorphism of diopside by talcand serpentine in (Ni Mg)Cl
2aqueous solutionsrdquo Geochimica
et Cosmochimica Acta vol 52 no 2 pp 415ndash424 1988[72] A E Williams-Jones C Normand H Clark Vali Jr R F
Martin A Dufresne and Nayebzadeh A ldquoControls of amphi-bole formation in chrysotile from the Jeffrey Mine AsbestosQuebecrdquo inTheHealth Effects Effects of Chrysotile Asbestos R PNolan AM LangerM RossWicks F J andMartin F R Edsvol 5 pp 89ndash104 The Mineralogical Association of CanadaQuebec Quebec Canada 2001
[73] B W Evans ldquoThe serpentinite multisystem revisited chrysotileis metastablerdquo International Geology Review vol 46 no 6 pp479ndash506 2004
[74] I Gunnarsson and S Arnorsson ldquoAmorphous silica solubilityand the thermodynamic properties of H
4SiO∘4in the range of
0∘ to 350∘C at Psatrdquo Geochimica et Cosmochimica Acta vol 64no 13 pp 2295ndash2307 2000
[75] M W Bodine Jr ldquoTrioctahedral clay mineral assemblages inPaleozoic marine evaporite rocksrdquo in Proceedings of the Pre-sented in the Sixth International Symposium on Salt vol 1 pp267ndash284 Toronto Canada 1983
[76] W Schreyer and K Abraham ldquoThree-stage metamorphic his-tory of a whiteschist from Sar e Sang Afghanistan as part ofa former evaporite depositrdquo Contributions to Mineralogy andPetrology vol 59 no 2 pp 111ndash130 1976
[77] T Angerer and S G Hagemann ldquoThe BIF-hosted high-gradeiron ore deposits in the archean koolyanobbing greenstonebelt Western Australia structural control on synorogenic-and weathering-related magnetite- hematite- and goethite-rich iron orerdquo Economic Geology vol 105 no 5 pp 917ndash9452010
[78] P Duuring and S Hagemann ldquoLeaching of silica bands andconcentration of magnetite in Archean BIF by hypogene fluidsBeebyn Fe ore deposit Yilgarn Craton Western AustraliardquoMineralium Deposita vol 48 no 3 pp 341ndash370 2013
[79] D Shin and I Lee ldquoFluid inclusions and their stable isotopegeochemistry of the carbonate-hosted talc deposits near theCretaceous Muamsa Granite South Koreardquo Geochemical Jour-nal vol 40 no 1 pp 69ndash85 2006
[80] P G Novgorodov ldquoSolubility of quartz in anH2OndashCO
2mixture
at 700 degrees C and pressures of 3 and 5 kbarsrdquoGeokhimiya pp1484ndash1489 1975
[81] T M Gerlach ldquoChemical characteristics of the volcanic gasesfrom Nyiragongo lava lake and the generation of CH
4-rich
fluid inclusions in alkaline rocksrdquo Journal of Volcanology ampGeothermal Research vol 8 no 2-4 pp 177ndash189 1980
[82] J V Walther and P M Orville ldquoVolatile production and trans-port in regional metamorphismrdquo Contributions to Mineralogyand Petrology vol 79 no 3 pp 252ndash257 1982
[83] W F Giggenbach ldquoThe origin and evolution of fluids inmagmatic-hydrothermal systemsrdquo in Geochemistry of Hydro-thermalOreDeposits H L Barnes Ed pp 737ndash796WileyNewYork NY USA 3 edition 1997
[84] J B Lowenstern ldquoCarbon dioxide in magmas and implicationsfor hydrothermal systemsrdquoMineralium Deposita vol 36 no 6pp 490ndash502 2001
[85] R Kerrich and W S Fyfe ldquoThe gold-carbonate associationsource of CO
2 and CO
2fixation reactions in Archaean lode
depositsrdquo Chemical Geology vol 33 no 1ndash4 pp 265ndash294 1981
[86] P I Nabelek ldquoCalc-silicate reactions and bedding-controlledisotopic exchange in the Notch Peak aureole Utah implicationsfor differential fluid fluxes with metamorphic graderdquo Journal ofMetamorphic Geology vol 20 no 4 pp 429ndash440 2002
[87] P I Nabelek ldquoFluid evolution and kinetics of metamorphicreactions in calc-silicate contact aureoles - From H
2O to CO
2
and backrdquo Geology vol 35 no 10 pp 927ndash930 2007[88] H G Machel ldquoBacterial and thermochemical sulfate reduction
in diagenetic settings - old and new insightsrdquo SedimentaryGeology vol 140 no 1-2 pp 143ndash175 2001
[89] L Stalker P Farrimond and S R Larter ldquoWater as an oxygensource for the production of oxygenated compounds (includingCO2precursors) during kerogen maturationrdquo Organic Geo-
chemistry vol 22 no 3-5 pp 477ndashIN4 1994[90] Z K Shipton J P Evans D Kirschner P T Kolesar A P
Williams and J Heath ldquoAnalysis of CO2leakage through lsquolow-
permeabilityrsquo faults from natural reservoirs in the ColoradoPlateau east-central Utahrdquo Geological Society Special Publica-tion vol 233 pp 43ndash58 2004
[91] J Byerlee ldquoFriction overpressure and fault normal compres-sionrdquo Geophysical Research Letters vol 17 no 12 pp 2109ndash21121990
[92] C Morrow B Radney and J Byerlee ldquoChapter 3 frictionalstrength and the effective pressure law of montmorillonite andlllite claysrdquo International Geophysics vol 51 no C pp 69ndash881992
[93] C A Morrow D E Moore and D A Lockner ldquoThe effectof mineral bond strength and adsorbed water on fault gougefrictional strengthrdquo Geophysical Research Letters vol 27 no 6pp 815ndash818 2000
[94] D A Lockner C Morrow D Moore and S Hickman ldquoLowstrength of deep San Andreas fault gouge from SAFOD corerdquoNature vol 472 no 7341 pp 82ndash86 2011
[95] D EMoore andM J Rymer ldquoTalc-bearing serpentinite and thecreeping section of the San Andreas faultrdquo Nature vol 448 no7155 pp 795ndash797 2007
[96] DH Zenger ldquoDiscussion lsquoOn the formation and occurrence ofsaddle dolomitersquordquo Journal of Sedimentary Petrology vol 51 no4 pp 1350ndash1352 1981
[97] DAKatzG P Eberli P K Swart andL B Smith Jr ldquoTectonic-hydrothermal brecciation associated with calcite precipitationand permeability destruction in Mississippian carbonate reser-voirs Montana and Wyomingrdquo AAPG Bulletin vol 90 no 11pp 1803ndash1841 2006
[98] M Esteban and C Taberner ldquoSecondary porosity developmentduring late burial in carbonate reservoirs as a result of mixingandor cooling of brinesrdquo Journal of Geochemical Explorationvol 78-79 pp 355ndash359 2003
[99] H G MacHel ldquoInvestigations of burial diagenesis in carbonatehydrocarbon reservoir rocksrdquoGeoscience Canada vol 32 no 3pp 103ndash128 2005
[100] J A Sagan and B S Hart ldquoThree-dimensional seismic-baseddefinition of fault-related porosity development Trenton-BlackRiver interval Saybrook Ohiordquo AAPG Bulletin vol 90 no 11pp 1763ndash1785 2006
[101] F Xing and S Li ldquoGenesis and environment characteristics ofdolomite-hosted quartz and its significance for hydrocarbonexploration in Keping Area Tarim Basin Chinardquo Journal ofEarth Science vol 23 no 4 pp 476ndash489 2012
[102] L Yun and Z Cao ldquoHydrocarbon enrichment pattern andexploration potential of the Ordovician in Shunnan area TarimBasinrdquo Oil and Gas Geology vol 35 no 6 pp 788ndash797 2014
14 Geofluids
[103] Y Li N Ye X Yuan Q Huang B Su and R Zhou ldquoGeologicaland geochemical characteristics of silicified hydrothermal fluidsin Well Shunnan 4 Tarim Basinrdquo Oil and Gas Geology vol 36no 6 pp 934ndash944 2015
[104] L Qi ldquoOil and gas breakthrough in ultra-deep Ordoviciancarbonate formations in Shuntuoguole uplift Tarim BasinrdquoChina Petroleum Exploration vol 21 no 3 pp 38ndash51 2016 (inChinese with English abstract)
[105] H R Qing ldquoAn introduction of petrology and diagenesis ofultra-deep water carbonate reservoirs from the Atlantic Oceanoffshore Brazilrdquo 2017 Oral presentation at Wuxi Institute ofPetroleum Geology of SINOPEC Wuxi China
[106] G J Simandl and S Paradisl ldquoCarbonate-hosted talcrdquo SelectedBritish ColumbiaMineral Deposit Profiles vol 3 pp 35ndash38 1999
[107] Y K Kharaka D R Cole S D Hovorka W D Gunter K GKnauss and BM Freifeld ldquoGas-water-rock interactions in FrioFormation following CO
2injection implications for the storage
of greenhouse gases in sedimentary basinsrdquoGeology vol 34 no7 pp 577ndash580 2006
[108] Z Duan and D Li ldquoCoupled phase and aqueous speciesequilibrium of the H
2OndashCO
2ndashNaClndashCaCO
3system from 0 to
250∘C 1 to 1000 bar with NaCl concentrations up to saturationof haliterdquo Geochimica et Cosmochimica Acta vol 72 no 20 pp5128ndash5145 2008
[109] M R Giles and J DMarshall ldquoConstraints on the developmentof secondary porosity in the subsurface re-evaluation of pro-cessesrdquoMarine and PetroleumGeology vol 3 no 3 pp 243ndash2551986
[110] O S Pokrovsky S V Golubev and J Schott ldquoDissolution kinet-ics of calcite dolomite and magnesite at 25∘C and 0 to 50 atmpCO2rdquo Chemical Geology vol 217 no 3-4 pp 239ndash255 2005
[111] P Cao Z T Karpyn and L Li ldquoThe role of host rock pro-perties in determining potential CO
2migration pathwaysrdquo
International Journal of Greenhouse Gas Control vol 45 pp 18ndash26 2016
[112] M D Fishburn ldquoSignificant results of deep drilling at ElkHills Kern County Californiardquo in Structure Stratigraphy andHydrocarbon Occurrences of the San Joaquin Basin CaliforniaG K Kuespert and S A Reid Eds vol 64 pp 157ndash167 PacificSections Society of Economic Paleontologists and Mineralo-gists and American Association of Petroleum Geologists 1990
[113] E Povoden M Horacek and R Abart ldquoContact metamor-phism of siliceous dolomite and impure limestones from theWerfen formation in the eastern Monzoni contact aureolerdquoMineralogy and Petrology vol 76 no 1-2 pp 99ndash120 2002
[114] S Yuan I-M Chou R C Burruss X Wang and J Li ldquoDispro-portionation and thermochemical sulfate reduction reactions inSndashH2OndashCH
4and SndashD
2OndashCH
4systems from 200 to 340∘C at
elevated pressuresrdquo Geochimica et Cosmochimica Acta vol 118pp 263ndash275 2013
[115] X Wang I-M Chou W Hu and R C Burruss ldquoIn situ obser-vations of liquid-liquid phase separation in aqueous MgSO
4
solutions geological and geochemical implicationsrdquo Geochim-ica et Cosmochimica Acta vol 103 pp 1ndash10 2013
[116] X Wang Y Wan W Hu et al ldquoIn situ observations of liquid-liquid phase separation in aqueous ZnSO
4solutions at tem-
peratures up to 400∘C Implications for Zn2+ndashSO2minus4
[117] X Wang IM Chou W Hu Y Wan and Z Li ldquoPropertiesof lithium under hydrothermal conditions revealed by in situ
Raman spectroscopic characterization of Li2O-SO
3-H2O(D2O)
systems at temperatures up to 420∘Crdquo Chemical Geology vol451 pp 104ndash115 2017
[118] L Shang I-M Chou W Lu R C Burruss and Y ZhangldquoDetermination of diffusion coefficients of hydrogen in fusedsilica between 296 and 523 K by Raman spectroscopy and appli-cation of fused silica capillaries in studying redox reactionsrdquoGeochimica et CosmochimicaActa vol 73 no 18 pp 5435ndash54432009
[119] M Dargent J Dubessy L Truche E F Bazarkina C Nguyen-Trung and P Robert ldquoExperimental study of uranyl(VI) chlo-ride complex formation in acidic LiCl aqueous solutions underhydrothermal conditions (T = 21∘Cndash350∘C Psat) using Ramanspectroscopyrdquo European Journal ofMineralogy vol 25 no 5 pp765ndash775 2013
[120] YWanXWangWHu and I-MChou ldquoRaman spectroscopicobservations of the ion association between Mg2+ and SO2minus
4
in MgSO4-saturated droplets at temperatures of le380∘Crdquo The
Journal of Physical Chemistry A vol 119 no 34 pp 9027ndash90362015
[121] Y Wan X Wang W Hu I M Chou Y Chen and Z Xu ldquoInsitu optical and Raman spectroscopic observations of the effectsof pressure and fluid composition on liquidliquid phase separa-tion in aqueous cadmium sulfate solutions (=400∘C 50MPa)with geological and geochemical implicationsrdquo Geochimica etCosmochimica Acta vol 211 pp 133ndash152 2017
[122] W L Marshall ldquoAmorphous silica solubilitiesmdashI Behavior inaqueous sodium nitrate solutions 25ndash300∘C 0ndash6 molalrdquo Geo-chimica et Cosmochimica Acta vol 44 no 7 pp 907ndash913 1980
[123] C-T A Chen andW LMarshall ldquoAmorphous silica solubilitiesIV Behavior in pure water and aqueous sodium chloridesodium sulfate magnesium chloride and magnesium sulfatesolutions up to 350∘Crdquo Geochimica et Cosmochimica Acta vol46 no 2 pp 279ndash287 1982
[124] B A Fleming and D A Crerar ldquoSilicic acid ionization and cal-culation of silica solubility at elevated temperature and pHapplication to geothermal fluid processing and reinjectionrdquoGeothermics vol 11 no 1 pp 15ndash29 1982
[70] B W Evans and S Guggenheim ldquoTalc phyrophyllite andrelated mineralsrdquo in Reviews in Mineralogy S W Bailey Edvol 19 pp 225ndash294 1988
[71] B Velde ldquoExperimental pseudomorphism of diopside by talcand serpentine in (Ni Mg)Cl
2aqueous solutionsrdquo Geochimica
et Cosmochimica Acta vol 52 no 2 pp 415ndash424 1988[72] A E Williams-Jones C Normand H Clark Vali Jr R F
Martin A Dufresne and Nayebzadeh A ldquoControls of amphi-bole formation in chrysotile from the Jeffrey Mine AsbestosQuebecrdquo inTheHealth Effects Effects of Chrysotile Asbestos R PNolan AM LangerM RossWicks F J andMartin F R Edsvol 5 pp 89ndash104 The Mineralogical Association of CanadaQuebec Quebec Canada 2001
[73] B W Evans ldquoThe serpentinite multisystem revisited chrysotileis metastablerdquo International Geology Review vol 46 no 6 pp479ndash506 2004
[74] I Gunnarsson and S Arnorsson ldquoAmorphous silica solubilityand the thermodynamic properties of H
4SiO∘4in the range of
0∘ to 350∘C at Psatrdquo Geochimica et Cosmochimica Acta vol 64no 13 pp 2295ndash2307 2000
[75] M W Bodine Jr ldquoTrioctahedral clay mineral assemblages inPaleozoic marine evaporite rocksrdquo in Proceedings of the Pre-sented in the Sixth International Symposium on Salt vol 1 pp267ndash284 Toronto Canada 1983
[76] W Schreyer and K Abraham ldquoThree-stage metamorphic his-tory of a whiteschist from Sar e Sang Afghanistan as part ofa former evaporite depositrdquo Contributions to Mineralogy andPetrology vol 59 no 2 pp 111ndash130 1976
[77] T Angerer and S G Hagemann ldquoThe BIF-hosted high-gradeiron ore deposits in the archean koolyanobbing greenstonebelt Western Australia structural control on synorogenic-and weathering-related magnetite- hematite- and goethite-rich iron orerdquo Economic Geology vol 105 no 5 pp 917ndash9452010
[78] P Duuring and S Hagemann ldquoLeaching of silica bands andconcentration of magnetite in Archean BIF by hypogene fluidsBeebyn Fe ore deposit Yilgarn Craton Western AustraliardquoMineralium Deposita vol 48 no 3 pp 341ndash370 2013
[79] D Shin and I Lee ldquoFluid inclusions and their stable isotopegeochemistry of the carbonate-hosted talc deposits near theCretaceous Muamsa Granite South Koreardquo Geochemical Jour-nal vol 40 no 1 pp 69ndash85 2006
[80] P G Novgorodov ldquoSolubility of quartz in anH2OndashCO
2mixture
at 700 degrees C and pressures of 3 and 5 kbarsrdquoGeokhimiya pp1484ndash1489 1975
[81] T M Gerlach ldquoChemical characteristics of the volcanic gasesfrom Nyiragongo lava lake and the generation of CH
4-rich
fluid inclusions in alkaline rocksrdquo Journal of Volcanology ampGeothermal Research vol 8 no 2-4 pp 177ndash189 1980
[82] J V Walther and P M Orville ldquoVolatile production and trans-port in regional metamorphismrdquo Contributions to Mineralogyand Petrology vol 79 no 3 pp 252ndash257 1982
[83] W F Giggenbach ldquoThe origin and evolution of fluids inmagmatic-hydrothermal systemsrdquo in Geochemistry of Hydro-thermalOreDeposits H L Barnes Ed pp 737ndash796WileyNewYork NY USA 3 edition 1997
[84] J B Lowenstern ldquoCarbon dioxide in magmas and implicationsfor hydrothermal systemsrdquoMineralium Deposita vol 36 no 6pp 490ndash502 2001
[85] R Kerrich and W S Fyfe ldquoThe gold-carbonate associationsource of CO
2 and CO
2fixation reactions in Archaean lode
depositsrdquo Chemical Geology vol 33 no 1ndash4 pp 265ndash294 1981
[86] P I Nabelek ldquoCalc-silicate reactions and bedding-controlledisotopic exchange in the Notch Peak aureole Utah implicationsfor differential fluid fluxes with metamorphic graderdquo Journal ofMetamorphic Geology vol 20 no 4 pp 429ndash440 2002
[87] P I Nabelek ldquoFluid evolution and kinetics of metamorphicreactions in calc-silicate contact aureoles - From H
2O to CO
2
and backrdquo Geology vol 35 no 10 pp 927ndash930 2007[88] H G Machel ldquoBacterial and thermochemical sulfate reduction
in diagenetic settings - old and new insightsrdquo SedimentaryGeology vol 140 no 1-2 pp 143ndash175 2001
[89] L Stalker P Farrimond and S R Larter ldquoWater as an oxygensource for the production of oxygenated compounds (includingCO2precursors) during kerogen maturationrdquo Organic Geo-
chemistry vol 22 no 3-5 pp 477ndashIN4 1994[90] Z K Shipton J P Evans D Kirschner P T Kolesar A P
Williams and J Heath ldquoAnalysis of CO2leakage through lsquolow-
permeabilityrsquo faults from natural reservoirs in the ColoradoPlateau east-central Utahrdquo Geological Society Special Publica-tion vol 233 pp 43ndash58 2004
[91] J Byerlee ldquoFriction overpressure and fault normal compres-sionrdquo Geophysical Research Letters vol 17 no 12 pp 2109ndash21121990
[92] C Morrow B Radney and J Byerlee ldquoChapter 3 frictionalstrength and the effective pressure law of montmorillonite andlllite claysrdquo International Geophysics vol 51 no C pp 69ndash881992
[93] C A Morrow D E Moore and D A Lockner ldquoThe effectof mineral bond strength and adsorbed water on fault gougefrictional strengthrdquo Geophysical Research Letters vol 27 no 6pp 815ndash818 2000
[94] D A Lockner C Morrow D Moore and S Hickman ldquoLowstrength of deep San Andreas fault gouge from SAFOD corerdquoNature vol 472 no 7341 pp 82ndash86 2011
[95] D EMoore andM J Rymer ldquoTalc-bearing serpentinite and thecreeping section of the San Andreas faultrdquo Nature vol 448 no7155 pp 795ndash797 2007
[96] DH Zenger ldquoDiscussion lsquoOn the formation and occurrence ofsaddle dolomitersquordquo Journal of Sedimentary Petrology vol 51 no4 pp 1350ndash1352 1981
[97] DAKatzG P Eberli P K Swart andL B Smith Jr ldquoTectonic-hydrothermal brecciation associated with calcite precipitationand permeability destruction in Mississippian carbonate reser-voirs Montana and Wyomingrdquo AAPG Bulletin vol 90 no 11pp 1803ndash1841 2006
[98] M Esteban and C Taberner ldquoSecondary porosity developmentduring late burial in carbonate reservoirs as a result of mixingandor cooling of brinesrdquo Journal of Geochemical Explorationvol 78-79 pp 355ndash359 2003
[99] H G MacHel ldquoInvestigations of burial diagenesis in carbonatehydrocarbon reservoir rocksrdquoGeoscience Canada vol 32 no 3pp 103ndash128 2005
[100] J A Sagan and B S Hart ldquoThree-dimensional seismic-baseddefinition of fault-related porosity development Trenton-BlackRiver interval Saybrook Ohiordquo AAPG Bulletin vol 90 no 11pp 1763ndash1785 2006
[101] F Xing and S Li ldquoGenesis and environment characteristics ofdolomite-hosted quartz and its significance for hydrocarbonexploration in Keping Area Tarim Basin Chinardquo Journal ofEarth Science vol 23 no 4 pp 476ndash489 2012
[102] L Yun and Z Cao ldquoHydrocarbon enrichment pattern andexploration potential of the Ordovician in Shunnan area TarimBasinrdquo Oil and Gas Geology vol 35 no 6 pp 788ndash797 2014
14 Geofluids
[103] Y Li N Ye X Yuan Q Huang B Su and R Zhou ldquoGeologicaland geochemical characteristics of silicified hydrothermal fluidsin Well Shunnan 4 Tarim Basinrdquo Oil and Gas Geology vol 36no 6 pp 934ndash944 2015
[104] L Qi ldquoOil and gas breakthrough in ultra-deep Ordoviciancarbonate formations in Shuntuoguole uplift Tarim BasinrdquoChina Petroleum Exploration vol 21 no 3 pp 38ndash51 2016 (inChinese with English abstract)
[105] H R Qing ldquoAn introduction of petrology and diagenesis ofultra-deep water carbonate reservoirs from the Atlantic Oceanoffshore Brazilrdquo 2017 Oral presentation at Wuxi Institute ofPetroleum Geology of SINOPEC Wuxi China
[106] G J Simandl and S Paradisl ldquoCarbonate-hosted talcrdquo SelectedBritish ColumbiaMineral Deposit Profiles vol 3 pp 35ndash38 1999
[107] Y K Kharaka D R Cole S D Hovorka W D Gunter K GKnauss and BM Freifeld ldquoGas-water-rock interactions in FrioFormation following CO
2injection implications for the storage
of greenhouse gases in sedimentary basinsrdquoGeology vol 34 no7 pp 577ndash580 2006
[108] Z Duan and D Li ldquoCoupled phase and aqueous speciesequilibrium of the H
2OndashCO
2ndashNaClndashCaCO
3system from 0 to
250∘C 1 to 1000 bar with NaCl concentrations up to saturationof haliterdquo Geochimica et Cosmochimica Acta vol 72 no 20 pp5128ndash5145 2008
[109] M R Giles and J DMarshall ldquoConstraints on the developmentof secondary porosity in the subsurface re-evaluation of pro-cessesrdquoMarine and PetroleumGeology vol 3 no 3 pp 243ndash2551986
[110] O S Pokrovsky S V Golubev and J Schott ldquoDissolution kinet-ics of calcite dolomite and magnesite at 25∘C and 0 to 50 atmpCO2rdquo Chemical Geology vol 217 no 3-4 pp 239ndash255 2005
[111] P Cao Z T Karpyn and L Li ldquoThe role of host rock pro-perties in determining potential CO
2migration pathwaysrdquo
International Journal of Greenhouse Gas Control vol 45 pp 18ndash26 2016
[112] M D Fishburn ldquoSignificant results of deep drilling at ElkHills Kern County Californiardquo in Structure Stratigraphy andHydrocarbon Occurrences of the San Joaquin Basin CaliforniaG K Kuespert and S A Reid Eds vol 64 pp 157ndash167 PacificSections Society of Economic Paleontologists and Mineralo-gists and American Association of Petroleum Geologists 1990
[113] E Povoden M Horacek and R Abart ldquoContact metamor-phism of siliceous dolomite and impure limestones from theWerfen formation in the eastern Monzoni contact aureolerdquoMineralogy and Petrology vol 76 no 1-2 pp 99ndash120 2002
[114] S Yuan I-M Chou R C Burruss X Wang and J Li ldquoDispro-portionation and thermochemical sulfate reduction reactions inSndashH2OndashCH
4and SndashD
2OndashCH
4systems from 200 to 340∘C at
elevated pressuresrdquo Geochimica et Cosmochimica Acta vol 118pp 263ndash275 2013
[115] X Wang I-M Chou W Hu and R C Burruss ldquoIn situ obser-vations of liquid-liquid phase separation in aqueous MgSO
4
solutions geological and geochemical implicationsrdquo Geochim-ica et Cosmochimica Acta vol 103 pp 1ndash10 2013
[116] X Wang Y Wan W Hu et al ldquoIn situ observations of liquid-liquid phase separation in aqueous ZnSO
4solutions at tem-
peratures up to 400∘C Implications for Zn2+ndashSO2minus4
[117] X Wang IM Chou W Hu Y Wan and Z Li ldquoPropertiesof lithium under hydrothermal conditions revealed by in situ
Raman spectroscopic characterization of Li2O-SO
3-H2O(D2O)
systems at temperatures up to 420∘Crdquo Chemical Geology vol451 pp 104ndash115 2017
[118] L Shang I-M Chou W Lu R C Burruss and Y ZhangldquoDetermination of diffusion coefficients of hydrogen in fusedsilica between 296 and 523 K by Raman spectroscopy and appli-cation of fused silica capillaries in studying redox reactionsrdquoGeochimica et CosmochimicaActa vol 73 no 18 pp 5435ndash54432009
[119] M Dargent J Dubessy L Truche E F Bazarkina C Nguyen-Trung and P Robert ldquoExperimental study of uranyl(VI) chlo-ride complex formation in acidic LiCl aqueous solutions underhydrothermal conditions (T = 21∘Cndash350∘C Psat) using Ramanspectroscopyrdquo European Journal ofMineralogy vol 25 no 5 pp765ndash775 2013
[120] YWanXWangWHu and I-MChou ldquoRaman spectroscopicobservations of the ion association between Mg2+ and SO2minus
4
in MgSO4-saturated droplets at temperatures of le380∘Crdquo The
Journal of Physical Chemistry A vol 119 no 34 pp 9027ndash90362015
[121] Y Wan X Wang W Hu I M Chou Y Chen and Z Xu ldquoInsitu optical and Raman spectroscopic observations of the effectsof pressure and fluid composition on liquidliquid phase separa-tion in aqueous cadmium sulfate solutions (=400∘C 50MPa)with geological and geochemical implicationsrdquo Geochimica etCosmochimica Acta vol 211 pp 133ndash152 2017
[122] W L Marshall ldquoAmorphous silica solubilitiesmdashI Behavior inaqueous sodium nitrate solutions 25ndash300∘C 0ndash6 molalrdquo Geo-chimica et Cosmochimica Acta vol 44 no 7 pp 907ndash913 1980
[123] C-T A Chen andW LMarshall ldquoAmorphous silica solubilitiesIV Behavior in pure water and aqueous sodium chloridesodium sulfate magnesium chloride and magnesium sulfatesolutions up to 350∘Crdquo Geochimica et Cosmochimica Acta vol46 no 2 pp 279ndash287 1982
[124] B A Fleming and D A Crerar ldquoSilicic acid ionization and cal-culation of silica solubility at elevated temperature and pHapplication to geothermal fluid processing and reinjectionrdquoGeothermics vol 11 no 1 pp 15ndash29 1982
[103] Y Li N Ye X Yuan Q Huang B Su and R Zhou ldquoGeologicaland geochemical characteristics of silicified hydrothermal fluidsin Well Shunnan 4 Tarim Basinrdquo Oil and Gas Geology vol 36no 6 pp 934ndash944 2015
[104] L Qi ldquoOil and gas breakthrough in ultra-deep Ordoviciancarbonate formations in Shuntuoguole uplift Tarim BasinrdquoChina Petroleum Exploration vol 21 no 3 pp 38ndash51 2016 (inChinese with English abstract)
[105] H R Qing ldquoAn introduction of petrology and diagenesis ofultra-deep water carbonate reservoirs from the Atlantic Oceanoffshore Brazilrdquo 2017 Oral presentation at Wuxi Institute ofPetroleum Geology of SINOPEC Wuxi China
[106] G J Simandl and S Paradisl ldquoCarbonate-hosted talcrdquo SelectedBritish ColumbiaMineral Deposit Profiles vol 3 pp 35ndash38 1999
[107] Y K Kharaka D R Cole S D Hovorka W D Gunter K GKnauss and BM Freifeld ldquoGas-water-rock interactions in FrioFormation following CO
2injection implications for the storage
of greenhouse gases in sedimentary basinsrdquoGeology vol 34 no7 pp 577ndash580 2006
[108] Z Duan and D Li ldquoCoupled phase and aqueous speciesequilibrium of the H
2OndashCO
2ndashNaClndashCaCO
3system from 0 to
250∘C 1 to 1000 bar with NaCl concentrations up to saturationof haliterdquo Geochimica et Cosmochimica Acta vol 72 no 20 pp5128ndash5145 2008
[109] M R Giles and J DMarshall ldquoConstraints on the developmentof secondary porosity in the subsurface re-evaluation of pro-cessesrdquoMarine and PetroleumGeology vol 3 no 3 pp 243ndash2551986
[110] O S Pokrovsky S V Golubev and J Schott ldquoDissolution kinet-ics of calcite dolomite and magnesite at 25∘C and 0 to 50 atmpCO2rdquo Chemical Geology vol 217 no 3-4 pp 239ndash255 2005
[111] P Cao Z T Karpyn and L Li ldquoThe role of host rock pro-perties in determining potential CO
2migration pathwaysrdquo
International Journal of Greenhouse Gas Control vol 45 pp 18ndash26 2016
[112] M D Fishburn ldquoSignificant results of deep drilling at ElkHills Kern County Californiardquo in Structure Stratigraphy andHydrocarbon Occurrences of the San Joaquin Basin CaliforniaG K Kuespert and S A Reid Eds vol 64 pp 157ndash167 PacificSections Society of Economic Paleontologists and Mineralo-gists and American Association of Petroleum Geologists 1990
[113] E Povoden M Horacek and R Abart ldquoContact metamor-phism of siliceous dolomite and impure limestones from theWerfen formation in the eastern Monzoni contact aureolerdquoMineralogy and Petrology vol 76 no 1-2 pp 99ndash120 2002
[114] S Yuan I-M Chou R C Burruss X Wang and J Li ldquoDispro-portionation and thermochemical sulfate reduction reactions inSndashH2OndashCH
4and SndashD
2OndashCH
4systems from 200 to 340∘C at
elevated pressuresrdquo Geochimica et Cosmochimica Acta vol 118pp 263ndash275 2013
[115] X Wang I-M Chou W Hu and R C Burruss ldquoIn situ obser-vations of liquid-liquid phase separation in aqueous MgSO
4
solutions geological and geochemical implicationsrdquo Geochim-ica et Cosmochimica Acta vol 103 pp 1ndash10 2013
[116] X Wang Y Wan W Hu et al ldquoIn situ observations of liquid-liquid phase separation in aqueous ZnSO
4solutions at tem-
peratures up to 400∘C Implications for Zn2+ndashSO2minus4
[117] X Wang IM Chou W Hu Y Wan and Z Li ldquoPropertiesof lithium under hydrothermal conditions revealed by in situ
Raman spectroscopic characterization of Li2O-SO
3-H2O(D2O)
systems at temperatures up to 420∘Crdquo Chemical Geology vol451 pp 104ndash115 2017
[118] L Shang I-M Chou W Lu R C Burruss and Y ZhangldquoDetermination of diffusion coefficients of hydrogen in fusedsilica between 296 and 523 K by Raman spectroscopy and appli-cation of fused silica capillaries in studying redox reactionsrdquoGeochimica et CosmochimicaActa vol 73 no 18 pp 5435ndash54432009
[119] M Dargent J Dubessy L Truche E F Bazarkina C Nguyen-Trung and P Robert ldquoExperimental study of uranyl(VI) chlo-ride complex formation in acidic LiCl aqueous solutions underhydrothermal conditions (T = 21∘Cndash350∘C Psat) using Ramanspectroscopyrdquo European Journal ofMineralogy vol 25 no 5 pp765ndash775 2013
[120] YWanXWangWHu and I-MChou ldquoRaman spectroscopicobservations of the ion association between Mg2+ and SO2minus
4
in MgSO4-saturated droplets at temperatures of le380∘Crdquo The
Journal of Physical Chemistry A vol 119 no 34 pp 9027ndash90362015
[121] Y Wan X Wang W Hu I M Chou Y Chen and Z Xu ldquoInsitu optical and Raman spectroscopic observations of the effectsof pressure and fluid composition on liquidliquid phase separa-tion in aqueous cadmium sulfate solutions (=400∘C 50MPa)with geological and geochemical implicationsrdquo Geochimica etCosmochimica Acta vol 211 pp 133ndash152 2017
[122] W L Marshall ldquoAmorphous silica solubilitiesmdashI Behavior inaqueous sodium nitrate solutions 25ndash300∘C 0ndash6 molalrdquo Geo-chimica et Cosmochimica Acta vol 44 no 7 pp 907ndash913 1980
[123] C-T A Chen andW LMarshall ldquoAmorphous silica solubilitiesIV Behavior in pure water and aqueous sodium chloridesodium sulfate magnesium chloride and magnesium sulfatesolutions up to 350∘Crdquo Geochimica et Cosmochimica Acta vol46 no 2 pp 279ndash287 1982
[124] B A Fleming and D A Crerar ldquoSilicic acid ionization and cal-culation of silica solubility at elevated temperature and pHapplication to geothermal fluid processing and reinjectionrdquoGeothermics vol 11 no 1 pp 15ndash29 1982
