10
INTRODUCTION
Most European Countries have extensivegeological mapping programs for their offshoreExclusive Economic Zones. With the JOG-NL33-10 Ravenna map (at the 1:250,000scale), Italy began a similar project, nowextended to the entire Adriatic Sea (Fig. 3).The Adriatic is a key area as regards geologicalhazards (earthquakes, tsunamis, landslides,fluid-escape deformation), resources(hydrocarbon, fresh water, and sand for coastalreplenishment), human impact and increasingpollution.Synthetic geological mapping provides thebasis for any applied environmental study bymaking basic information available to a widerange of end-users. In offshore geologicalmapping, extensive areas can be covered onlyat much smaller scales than those used forgeological mapping on land because of thelarge costs implied in surveying marine areas.Marine-geology studies rely on complementarygeophysical techniques that are all based onsound emission (from hull-mounted or towedsources) and a device recording a signalscattered from the sea floor or the subsurface.The direct sampling of subsurface units allowsthe definition of depositional environmentsfrom facies, sedimentary structures andpalaeontological content. Sampling alsoprovides material (wood, foraminifera testsand mollusc shells) that can be used for datingusing several complementary methodologies.Stratigraphic information on stratal geometryand geochronological data can be combinedinto chronostratigraphic schemes with equally-spaced horizontal timelines defining theamount of stratigraphic time not represented bysedimentary units due to erosion (e.g. subaerialexposure during glacial sea-level lowstands andreworking during sea-level rise) or condenseddeposition during rapid sea-level rises and earlyhighstands (Figs. 4, 6A and 6B).
METHODOLOGY
The following main methodological points arereviewed and discussed:1) Bathymetric data (collection, validation,contouring and 3D rendering);2) Very-high resolution, true 3D seismicvolume images of a selected shelf sector;3) Acoustic seafloor responses on side scan-sonar records and mosaics.4) Seismic profiles using broadband soundsources and nested grids of variable resolution;5) Sampling techniques and relation betweenseismic reflectors and sediment composition;6) Biostratigraphic and geochronological dataand calibrations of significant seismicreflectors.
1) Bathymetric charts are fundamental to anygeological cartography of continental marginsjust as an accurate representation of landtopography is the starting point for anygeological mapping. In most cases, however,onshore topographic surveys are provided bydedicated Institutions (the Istituto GeograficoMilitare, in Italy) and are not under the directresponsibility of geological mapping projects.Conversely, offshore, bathymetric data need tobe collected as a necessary starting point for
53
Adriatic project
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Fig. 3 - Plan for the geological mapping of the Adriatic Sea following the pilot mapcompleted off Ravenna. The extent of the new geological maps (scale 1:250,000) isreported on the bathymetric map of the Adriatic basin. The thickness distribution of thelate-Holocene HST (in TWTT) is shown in green.
0-22-44-66-88-1010-1212-14
TRANGRESSIVE SYSTEMS TRACT (TST)
CHRONOISOPACH MAP45˚
44˚12˚ E 14˚13˚
milliseconds
N
0 20 40 km
ISMAR- CNR high-resolution
seismic database
Fig. 4 - Positioningchart of the ISMAR-CNR high resolution.seismic lines database.
0-22-44-66-1010-1414-1616-1818-20>20
45˚
44˚12˚ E 14˚
HIGHSTAND SYSTEMS TRACT (HST) CHRONOISOPACH MAP
13˚
milliseconds
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Fig. 5 - Thematic maps: thickness maps inTWTT and navigation map. The thickness ofthe highstand and transgressive system tractsare measured by high-resolution seismicprofiles and expressed in Two Way TravelTimes (TWTT). The transgressive recordincludes two depocentres; the nearshoredepocentre corresponds to prodelta mudssimilar in facies and geometric arrangementto the overlying highstand deposits. Theback-barrier and coastal transgressivedeposits have a reduced thickness and a morepatchy distribution.
TRINCARDI et alii
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detailed geomorphologic, stratigraphic andsedimentologic studies.Bathymetric data are essentially acquired usingtwo kinds of instruments: standard, single-beam sounders or multibeam systems. Thelatter systems cover a swath of the seafloor onboth sides of the ship’s nadir (this swathtypically corresponds to 3 to 5 times the waterdepth).Although originally designed for deep-waterstudies, multibeam systems have recently beenimplemented for shallow water investigations.These systems offer a vertical resolution of lessthan one metre and spatial resolutions of 2-5 m.A regional-scale bathymetric map fromconventional single beam soundings (Fig. 7)and a very high resolution swath bathymetry ofa particularly complex seafloor stretch in theCentral Adriatic are contrasted (offshoreOrtona; Fig. 8); contour lines are 5 and 1 m,respectively. Note that the metre-scalecomplexity of the area is averaged out in theregional contour based on conventionalbathymetric soundings. In general the choicebetween the two types of surveys andrepresentation depends on budgetaryconstraints and on the scope of the study.High resolution multibeam bathymetry showsmetre-scale shore-parallel undulations andshore-normal mud reliefs (in deeper waters)that remain undetected in conventional,single-beam surveys, where data are collectedsolely along the ship's tracks and need to bespatially interpolated over several hundred mto a few km. Bathymetric data can berepresented in Digital Terrain Models (DTM)with artificial illumination to highlightmorphological trends (Fig. 9) or in 3D blocks(Fig. 10: details shown by white squares inFig. 9). All these representations are of use inthe geological interpretation of bathymetrictrends. The same bathymetric data can also bereported in illuminated 3D blocks (Fig. 10,location in Fig. 9).
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43thick late-Holocene deposits
thin late-Holocene deposits
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A
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>
FIGURE 9B
FIGU
RE 8
FIGURE 9A
10 km
tim
e in
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ou
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yr
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14C (AMS) dates of peat layers
reported in calibrated yr
lsts
ls
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th i
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ts
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tp2tp1
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hs1hs2
Horizontal scale: ca. 1:780.000
Verticale scale: ca. 1:1500
Condensed Section
SECTION FF'
Late Glacial Maximum
Fig. 6A - Chronostratigraphic scheme of the late-Quaternary depositional sequence. This kind ofrepresentation allows the quantification of the portion ofstratigraphic time not recorded by continuous deposition.
In particular, the maximum flooding surface records manythousands of years of condensed deposition following thedrowning of the North Adriatic shelf and prior to theonset of the highstand progradation.
Late Quaternary Depositional Sequence
Late Quaternary
Depositional Sequence
Pleistocene Units
Pliocene Units
Pre-Pliocene Units
W E
base of Pliocene
Fig. 6B - Stratigraphic scheme of the adriatic basinfill (not to scale). The Late Quaternary sequenceconsists of a thin sediment cover above a thicker andmore complex fill of the Adriatic basin. Thisschematic geological section portrays theunconformity at the base of the Plio-Quaternary fill of
the Adriatic foreland basin, and is represented in theChart of the deeper geological structure that is notdiscussed here. The Plio-Quaternary basin fillconsists of two main sequences: an onlapping marinesequence, below, and a prograding continental toshallow marine sequence, above.
Fig. 7 - Bathymetry and location of earthquake epicentres inthe central Adriatic. An example of bathymetric contour fromconventional (single beam) sounders is shown along with thethickness distribution of the modern (late-Holocene) prodeltamud wedge. Areas of detailed investigation with very highfrequency multibeam systems (Figs. 8, 9 and 13) wereselected for the purposes of studying sediment deformationspossibly triggered by earthquake events (red dots showhistorical epicentres drawn from the literature).
mfs
ES1
TST
-75m
1 km15 m
A "buried"mud reliefs "outcropping"
mud reliefs
seafloor undulations
gas
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TST
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basementhigh
1 km15 m
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B "small"mud reliefs
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Adriatic project
2) 3D-seismic surveys allow the generation ofvolumes of seismic data and the representationof these data along preferred cuts includinghorizontal images that approximate time-lines.In the example (derived from a cooperation bet-ween IFREMER and ISMAR), a set of closely-spaced horizontal slices (offshore Ortona; Fig.11) shows evidence of soft-sediment deforma-tion (on the right) on the gently-dipping down-lap surface at the base of the Late HoloceneHST (location of the 3D survey in Fig. 9).
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Fig. 8 - Swath bathymetry offshore Ortona. The high-resolution, multibeam bathymetry shows metre-scale,shore-parallel undulations and shore-normal mud reliefs(in deeper waters) that remain undetected in conventionalsingle-beam surveys, where data are collected solelyalong the ship's tracks and need to be spatiallyinterpolated over several hundred metres to a fewkilometres.
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-95 m
Fig. 10a
Fig. 10b
Fig. 11
N
Fig. 11- 3D seismic survey offshore Ortona. Example ofclosely spaced horizontal slices from a VHR 3D seismicvolume (location in figure 9) showing: a) acousticmasking by gas-charged sediments (very narrow stripeon the left of each time slice); b) gently seaward-dippingreflectors (cut increasingly landward in shallower timeslices, bottom-up) under the maximum flooding surface(mfs, dashed red line). The deposits immediately abovethe mfs show a very complex pattern (on the right)ascribed to soft-sediment deformation at the base of theLate Holocene HST.
Fig. 9 - Digital terrain model offshoreOrtona. The Illuminated Digital TerrainModel (DTM) offshore Ortona docu-
ments the occurrence of elongated,shore-parallel undulations in
the muddy foreset of thelate-Holocene pro-
gradational cli-noform.Towards the
NE, these fea-tures are repla-
ced by disconti-nuous, shore-nor-
mal clusters ofmuddy reliefs in the
bottom set of the pro-gradational clinoform.
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Fig. 10- Blocks from DTM. The 3D blocks show that theshore-parallel undulations loose continuity proceedingdownslope (a) and that the mud reliefs have a NW-facinggentle side reflecting preferential deposition (b).
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3) Side-scan-sonar images complementbathymetric data by providing a view of theenergy that the sea floor is able to backscatter asa function of its morphology (the steeper theslope of a given feature, the larger the amountof energy backscattered) and lithology (themicro-scale seafloor roughness increases withsediment grain size and/or cementation).Depending on the frequency of the signalemitted, these side-scan sonar systems coverswaths of the sea floor that range from 100 m (at500 kHz) to several km (at few tens of kHz).
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Fig. 14- Slope angle map. The map of the seafloor gradients showsthe same features observed in Fig. 13 over a wider area. Thisrepresentation confirms that the elongated strips of increasedbackscatter are the steeper flanks of mud reliefs, rather than changesin seafloor sediment composition.
Fig. 13- Digital terrain model offshore Vieste. This DTM from multibeam bathymetry shows small scalereliefs with individual crests oriented parallel to structural and morphologic high to the SE (bottom right).
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seismic reflector capping the gas-prone unit = flooding surface ontop an abandoned deltaic lobe
gas-prone sediment
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LSTW E
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Fig. 16 - Profile 1 south of modern Po delta showing Roman-age buried lobe. Profile 1across the southern portion of the Po prodelta shows the downlapping surface at the baseof the very recent progradational wedge. Seismic stratigraphic correlation, supported bycore data (see next page), indicate that the basal downlap surface coincides with thetransgressive erosional surface (ravinement surface) bevelled during the late stages of theLate Quaternary sea-level rise. In the line drawing: LST denotes low-stand alluvial plaindeposits; TST denotes transgressive deposits with back-barrier or marine faciesrespectively below and above the ravinement surface (red line); and HST denotes LateHolocene prodelta deposits originated during the last 5,500 yrs, after the attainment of themodern sea-level high stand. HST deposits in green and grey are sandy (and gas-charged)
delta lobe of Roman age and Little-Ice-Age prodelta respectively. Age assignments rely oncomparisons with historical cartography on land and direct coring of the topset of theabandoned delta, cores RER96-1 to -3, or through the entire HST in distal areas.A particular challenge in geological mapping of coastal areas is posed by the collection ofseismic reflection data in very shallow-water environments, where reverberation from sandysediment and gas impregnation are common. This profile shows meaningful data up to theshoreface zone in water depths of about -3 m. These shallow-water data can be combined, onland, with historical maps, archaeological data, shallow drilling and other kinds ofgeophysical data, such as those from GPR (Ground Penetrating Radar). This shallow waterdomain is often included in the marine portion of Geological Maps at the 1:50,000 scale.
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3Fig. 15- Locationof profiles 1-3(see Figs. 16, 17and 18).
Profile 1
TRINCARDI et alii
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Fig. 12- Side scan-sonar mosaic. Example of 100-kHz side-scan mosaic of a portion of the conti-nental shelf off Vieste. The mosaic was acquired and processed by SOC (Southampton) and ISMAR(Bologna) as part of the EU project COSTA (COntinental slope STAbility). The line-spacing is 200m and pixel resolution is dm-scale (note trawl marks in the upper portion of the mosaic). In thisexample, the study area is uniformly characterised by mud deposition and the acoustic returns onthe side-scan sonar image reflect only the relief on the micromorphology of the seafloor. This inter-pretation is supported by several sediment cores.
4) Reflection seismic profiling is the maintechnique used in subsurface exploration. Thistechnique was originally developed for oilexploration using low-frequency sound sourcesand one or more receiving streamers to obtain2D and 3D images of several kilometres of theupper part of the Earth’s crust. Over the last twodecades, ultra-high resolution seismic stratigra-phic techniques have been developed adoptingportable broadband sound sources and single-channel receivers. In the field of ultra-highresolution seismic profiling two main kinds ofsound sources used are impulsive sources (toproduce a “spike” signal having a very shortwavelength) and sweep-modulated sources (fil-ter-matching the return signal with a well-defi-ned, prolonged, outgoing signal). The latter isnow very popular for high-resolution seismicstratigraphic surveys and has been adopted asthe main tool in the Marine GeologicalMapping project of the Adriatic. Three exam-ples of Chirp-sonar profiles along the Adriaticmargin are shown, with the same extreme verti-cal exaggeration (85x) to allow a more directcomparison between the gently dipping reflec-tors in the north and the steeper and more com-plex areas in the south.
area of non deposition or submarine erosion
during the last 5500 yr
offlap break
maximum flooding surface
most-recent prograding sigmoid (Little Ice Age
to Modern)
mfs1 km
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60
40
20ms
50
30
15 m
SW NE
Fig. 18 - Profile 3 across the Late Holocene Gargano subaqueousdelta. Profile 3 is from the Gargano subaqueous delta, a relevantcomponent of the late-Holocene HST, nourished by shore-parallelcurrents from the north. Here the clinoform geometry is moreevident with a subaqueous topset and foresets dipping as much as 1
deg. The most recent sigmoid is ascribed to the intervalencompassing the Little Ice Age and the last Century, based ondirect dating of the basal surface, multi-proxy reconstructions andinterpolations of sediment accumulation rates derived from short-lived radionuclides (210Pb).
Profile 3
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90
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NE
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gas-charged sediment
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Fig. 17- Profile 2 across the central adriatic margin penetrating stacked regressivesequences from Pleistocene glacial-interglacial cycles beneath a composite Late-Quaternary transgressive record. Profile 2 illustrates the HST Apennine mud wedgein an area of high sediment accumulation characterised by soft-sedimentdeformation and fluid escape (see also 3D images across basal mfs separating thedeformed section from the undisturbed TST below). Deformations affect prodeltaslope generating undulations and acoustically-transparent mud reliefs. Note thatthe basal low-angle downlap surface (mfs, dashed line) is above marine mudcharacterised by low-frequency and high-continuity reflectors. The transgressiverecord (TST) is tripartite and includes an intermediate progradational wedgerecording the Late-Glacial Holocene transition. Below this TST, older regressive sequences are separated by regionalunconformities (dashed lines) that originated during sea-level lowstands. Theseregressive sequences (FST+LST) record intervals of prolonged sea-level fall with a100-kyr cyclicity forced by astronomical cycles and amplified by the dynamic ofwaxing and waning ice caps.
Profile 2
Adriatic project
57
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MCS profile RF 2M(S15 Water Gun,24-Channel streamer)
Core RF93-77 (projected)Core CM92-43
(projected)
5 km
NW SE
Lower-PleistoceneprogradingLST wedges
late-Quaternary low-stand wedge(250 km of progradation took place during Oxygen Isotope Stage 2 along the basin axis)
28/25-kyrSequence Boundary
condensed distal equivalent oflate-Quaternary low-stand wedge
100
500
100 msec twtt
Middle Adriatic Deep
Fig. 19 - Complementary coring sites from expanded Last-Glacial Maximum wedge (yellow) and its distal pinch-out(core RF93-77) on the right.
Fig. 20- Example of box core in prodelta muds(left) and piston core (right). A box core in pro-delta muds (left) is subsampled for X-ray analy-sis (flat slabs) and geochemistry. In the exampleon the right, Piston core YD97-10 is compared tothe uncompressed trigger core (YD97-11). In thisexample the piston core (YD97-10) underwent acompression of ca. 400% at the core top; thiscan be quantified by comparing layers (the darkone is Mediterranean sapropel S1) to the uncom-pressed trigger core taken at the same site usinga light corer (YD97-11). Compression or sedi-ment losses should be taken into account whencorrelating coring sites and when reporting coreinformation on seismic profiles.
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BATHYMETRIC SECTION
sea level during LGM
transgressivecoastal deposits
transgressiveparalic depositsand incisedvalleys
transgressivebarrier-lagoonestuary systems
maximummarine ingression
modern sea level
14 kyr
17 kyr
11 kyr
5.5 kyr
5) Precisely navigated coring provides funda-mental information on sedimentary facies, bio-stratigraphy and geochronological control of theseafloor and subsurface sediment. Conventionalcoring methodologies, however, are severelylimited in their ability to penetrate sediments(reaching typical recoveries in the order of 7-8m and exceptional recoveries of 12-15 m), andany sampling strategy should take into accountthese limitations. However, a knowledge of thesubsurface geometry of depositional sequencesfrom seismic profiles allows the identificationof complementary targets. The RF 2M seismic profile provides an exampleof complementary core locations with a thickLate Quaternary progradational wedge (yellow)and its distal pinch-out. The older units underl-ying the pinch-out on the RF93-77 site, lieabout 200 m below the seafloor at site CM92-43, where drilling would be required to reachthe same reflectors (dashed red line).Sampling of surface and subsurface sedimentcan be achieved using a variety of complemen-tary techniques, depending on the expectedlithology. Box and Kasten coring are ideal forfacies reconstruction (large sample size), buthave limited penetration. Vibracoring also haslimited penetration (3-6 m), but recovers sam-ples in sandy deposits (a possible artifact is theliquefaction of sand and consequent loss of pri-mary structures). Free-fall (gravity) or piston coring (gravitycorer helped by a piston inside the barrel tocreate a depression and enhance penetration)recover up to 5 and 20 m, respectively, butcompression or loss of the core top are notinfrequent.The melting of the ice caps after the end of theLast Glacial Maximum caused a rapid eustaticrise of ca. 125 m and the consequent drowningof continental shelves. The most dramatic palaeogeographic changeaffected epicontinental shelves, including in theAdriatic, that underwent a substantial broade-ning.
Fig. 21- Adriatic palaeogeography during the Late Quaternary sea levl rise. The cartoonabove shows the extent of the Adriatic basin at the onset of the sea-level rise (dark blue),the location of drowned coastal lithosomes (yellow) and the extent of the basin culminating
at the time of maximum ingression (about 5.5 ka BP). The very low gradient of the northAdriatic shelf allows the monitoring of the phases of the eustatic rise that followed the endof the last glaciation and quantify the magnitude of the main melt water pulses.
depth (m)
disc
harg
e ra
te10
000
5000m
fs
Fairbanks (1989, 1990)
14C kyr B.P.
MW
PIB
MW
PIA
2 4 6 8 10 1214 16 18 200 2 4 6 8 10 12 14 16 180
age (kyr)calibrated kyr B.P.
(km
3 yr
-1)
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A B C D
E F G H
6) Biostratigraphic and geochronologicaldata sediment cores from different parts of abasin can be correlated based on the physicalproperties of layers (magnetic susceptibility, P-waves velocity, density), multiproxy environ-mental parameters (foraminifera, pollen, stableisotopes) and independent dating. Datingmethodologies include radiocarbon, tephroch-ronology (based on the correlation of volcano-genic layers) and palaeomagnetic saecularvariations. Radiocarbon dating is a methodo-logy widely used for dating covering the last30-40,000 years.The unstable isotope 14C, generated in the upperatmosphere by cosmic radiation bombardingatmospheric N, becomes fixed in the biospherethrough photosynthesis and food web. Whenany organism (plant or animal) dies, its ratio of14C to 12C (a stable isotope of C) begins to gra-dually decrease. The half-life of 14C (5730 yrs)is the time that passes to decrease to 1/2 thequantity at death. By measuring the remainingquantity of 14C, the age of the sample can becalculated.
13ß 00’
44ß 40’
13ß 10’
m04- AR00-45
m05-
A
A’CM95-17
CM95-18 44ß 30’
-30 -60m
10488,10440,10429calibrated years BP(9280–4014C age)
AR00-45
71/59M
C81/59
MC
3938
3938
4140
424140
43444546
42434445
A’
46
A ff f m
Rs
Morphologic section
CM95-18 CM95-17
Rs
Rs
tRs?m
cm 0
100
200
300
molluscsshell fragmentsbioturbation
clay
silt
sand
peat
Fig. 24- Muddy deposits fil-ling a valley incised intolower-TST deposits.Example of core through thetransgressive fill of anincised valley on the low-gradient Central Adriaticshelf. Rs is the ravinementsurface. Mud deposits in thevalley fill are intensely lami-nated.
85
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100
95
90
cm
Fig. 23 - Example of facies from sediment cores from chartNL33-10 Ravenna. Core A shows subaerially-exposedconsolidated sandy clays of the Last Glacial Maximum;core B shows the erosion surface above the consolidatedclays with a sandy-shelly lag, and a marine deposit finingupward above; cores C and D provide examples of back-barrier deposits with bioturbated peat layers with woodremnants (C), and thin storm beds with Hydrobia molluscs
(D); core E is a typical mud-fill of an inlet or estuary withbrackish fauna (Cerastoderma glaucum); cores F and Gshow reworked and mixed faunas from back-barrier(C.glaucum) coastal (Glycymeris insubrica) and offshore(Aporrhais pespelecani) deposits on the transgressiveerosion surface; core H from modern HST deposits showssilty storm beds encased in marine prodelta muds. Thevertical scale bar is 10 cm.
Fig. 22- Example of drowned barrierlagoon. Phases of enhanced sea levelrise are recorded by the drowning ofcoastal lagoons and barriers, locallyreworked into sand ridges. Thesedeposits can be precisely dated andtheir present water depth measuresthe amount of sea-level rise follo-wing their transgressive submergen-ce. An improved knowledge of therates of sea-level rise is importantwhen predicting environmental chan-ges induced by global warming andpossible further melting of ice caps.Furthermore, drowned barrier depo-sits are actively dredged in manyareas as they comprise an importantresource of sand for beach replenish-ment, particularly in densely develo-ped or tourist areas affected bycoastal erosion.
Fig. 25- Tephra layer from 79AD Plinian eruption ofVesuvius. Dating of knowntephra layers at sea and onland indicates that the 14Creservoir value has not heldconstant through time, butvaried significantly dependingon changes in water-atmo-sphere exchanges throughthermohaline circulation anddeep-sea ventilation. TheAdriatic is an ideal area fortephrochronology, althoughthese deposits are typicallyvery fine-grained, in contrastto more proximal areas (theexample above shows 79 ADpumice from the Tyrrhenianshelf some 150 km south ofVesuvius).
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Jun 2001Oct 2001
cm
05001000150020002500300035004000450050005500600065007000
20 60
Trees
Her
bs +
shru
bs
0.0040.006
-2-1
TOC (g
cm
yr)
0.04.08.0
Xlf-
flux
0 50100
IRM
300-
flux
00.4
Xfd
-flu
x
0.51.0
G.go
mitu
lus
0.5 1.0
G. r
uber
10 20 30
C. l
aevi
gata
car
inat
a
5 10
B. m
argi
nata
5 10
M.pa
danu
m
5 10
V.com
plan
ata
121518 21
T ûC(U
K-3
7)
100 0.2
yr BPFig. 28 - X-ray radiographs of box coresfrom a repeated site off Po delta. Digitally-recorded radiographs of repeated samplesfrom prodelta mud following Po River floodof Fall 2000 allow to study the preservationof flood layers (identified by the redarrowed bar), against erosion, compactionand bioturbation (EUROSTRATAFORMproject funded by the European Union andby the Office of Naval Research).
Fig. 29 - Multiproxy data from the Central Adriatic. A Multiproxy analysis of core data allows the unravelling ofenvironmental change in the geological past (PALICLAS EU project). In this example from a core retrieved in theAdriatic prodelta wedge, human impact can be disentangled from other environmental factors using magneticstratigraphy, biostratigraphy of foraminifera, and palinology. Independent geochronological techniques (14C dating,palaeomagnetism and tephrochronology) define the timing of climate change and human impact (such as forestclearance, cultivation and accelerated soil erosion) in the central Adriatic area since the Bronze Age (ca 3.7 ka BP).
REFERENCES
ASIOLI A., TRINCARDI F., LOWE J.J. & OLDFIELD F. (1999)-Short-term climate changes during the Last Glacial-Holocene transition: comparison between Mediterraneanrecords and the GRIP event stratigraphy. J. Quat. Sc., 14:373-381.ASIOLI A., TRINCARDI F., LOWE J.J., ARIZTEGUI D.,LANGONE L. & OLDFIELD F. (2001) - Sub-millennialclimatic oscillations in the Central Adriatic during thelast deglaciation: paleoceanographic implications. Quat.Sc. Rev., 20: 33-53.SERVIZIO GEOLOGICO D’I TALIA & REGIONE EMILIA -ROMAGNA (1999) - Carta Geologica d’Italia alla scala1:50.000 Foglio 223-Ravenna.SERVIZIO GEOLOGICO D’I TALIA & REGIONE EMILIA -ROMAGNA (in press.) - Carta Geologica d’Italia alla scala1:50.000 Foglio 256-Rimini.SERVIZIO GEOLOGICO D’I TALIA , ISTITUTO DI GEOLOGIA
MARINA & CONSIGLIO NAZIONALE DELLE RICERCHE(2001)- Carta Geologica dei mari italiani alla scala 1:250.000Foglio NL33-10-Ravenna, S.EL.CA. Firenze.CATTANEO A. & TRINCARDI F. (1999) - The LateQuaternary transgressive record in the Adriaticepicontinental sea: basin widening and faciespartitioning. In: K.M. BERGMAN & J.W. SNEDDEN (Eds),Isolated shallow marine sand bodies: sequencestratigraphic analysis and sedimentologic interpretation ,SEPM Spec. Publ., 64: 127-146.CATTANEO A., CORREGGIARI A. & TRINCARDI F. (2002)-Recognition of turbidite elements in the Late QuaternaryAdriatic basin: where are they and what do they tell us?In: J. MASCLE & F. BRIAND (Eds), Turbidite systems anddeep-sea fans in the Mediterranean and Black seas. –CIESM Workshop Series n. 17, Monaco,<www.ciesm.org/publications/Bucharest02.pdf>, 27-32.
CATTANEO A., CORREGGIARIA., LANGONE L. & TRINCARDI
F. (2003a) - The Late Holocene Gargano subaqueousdelta, Adriatic shelf: Sediment pathways and supplyfluctuations. Mar. Geol., 193: 61-91.CATTANEO A., CORREGGIARI A., PENITENTI D., TRINCARDI
F. & MARSSETT. (2003b) -Morphobathymetry of small-scale mud reliefs on the Adriatic shelf.In: J. LOCAT & J.MIENERT (Eds) Submarine mass movements and theirconsequences, 401-408, Kluwer, Amsterdam.CATTANEO A., CORREGGIARI A., MARSSETT., THOMAS Y.,MARSSET B. & TRINCARDI, F. - Seafloor undulationpatterns on the Adriatic shelf and comparison to deep-water sediment waves. Marine Geology (in press.).CORREGGIARI A., ROVERI M. & TRINCARDI F. (1996) -Late-Pleistocene and Holocene evolution of the NorthAdriatic Sea. Il Quaternario, 9: 697-704.CORREGGIARIA., TRINCARDI F., LANGONE L. & ROVERI M.(2001) - Styles of failure in heavily-sedimented highstandprodelta wedges on the Adriatic shelf.J. Sedim. Res., 71:218-236.FABBRI A., ARGNANI A., BORTOLUZZI G., CORREGGIARIA.,GAMBERI F., LIGI M., MARANI M., PENITENTI D., ROVERI
M. & TRINCARDI F. (2002) - Carta Geologica dei mariitaliani alla scala 1:250.000: guida al rilevamento.Quaderni Servizio Geologico, Serie III, 8: 101 pp.MARSSET T., MARSSET B., THOMAS Y., CATTANEO A.,TRINCARDI F. & COCHONAT P. - Detailed analysis of LateHolocene sedimentary features on the Adriatic shelf from3D very high resolution seismic data (TRIAD survey).Marine Geology (in press.).OLDFIELD F., ASIOLI A., ACCORSI C.A., MERCURI A.M.,JUGGINS S., LANGONE L., ROLPH T., TRINCARDI F., WOLFF
G., GIBBS Z., VIGLIOTTI L., FRIGNANI M., VAN DER POSTK.& BRANCH N. (2003) - A high resolution Late Holocene
palaeo environmental record from the central AdriaticSea. Quat. Sc. Rev., 22: 319-342.RIDENTE D. & TRINCARDI F. (2002) - Eustatic and tectoniccontrol on deposition and lateral variability ofQuaternary regressive sequences in the Adriatic basin(Italy). Marine Geology, 183: 1-21.TRINCARDI F., CORREGGIARIA. & ROVERI M. (1994) - LateQuaternary transgressive erosion and deposition in amodern epicontinental shelf: the Adriatic SemienclosedBasin.Geo-Mar. Lett., 14: 41-51.TRINCARDI F., ASIOLI A., CATTANEO A., CORREGGIARIA. &LANGONE L. (1996) - Stratigraphy of the Late Quaternarydeposits in the Central Adriatic basin and the record ofshort-term climatic events. Mem. Ist. Ital. Idrobiol., 55:39-70.TRINCARDI F. & CORREGGIARIA. (2000) - Muddy forced-regression deposits in the Adriatic basin and thecomposite nature of Quaternary sea level changes.In: (D.HUNT & D. GAWTHORPE(Eds), Sedimentary expression offorced regressions. Geological Society SpecialPublication, 172: 247-271.TRINCARDI F. & ARGNANI A. (Eds), with contributions ofASIOLI A., BORTOLUZZI G., CATTANEO A., CORREGGIARIA.,FABBRI A., GAMBERI F., LIGI M., PENITENTI D., ROVERI M.& TAVIANI M. (2001) - Note illustrative della CartaGeologica dei mari italiani alla scala 1:250.000 - FOGLIO
NL33-10 RAVENNA. Servizio Geologico d’Italia, Istitutodi Geologia Marina, Consiglio Nazionale delle Ricerche,S.EL.CA., 108 pp., Firenze.TRINCARDI F., CATTANEO A., CORREGGIARIA. & RIDENTE
D. - Evidence of soft-sediment deformation, fluid escape,sediment failure and regional weak layers within theLate Quaternary mud deposits of the Adriatic Sea.Marine Geology(in press.).
Fig. 26- Diagnostic fossil assemblages from Adriatic sediment cores. Examples of diagnosticfossil assemblages recovered from sediment cores; similar assemblages are recurrent in thegeological record of the Mediterranean basin at least since the early Pleistocene. A: pre-transgressive continental facies representing a shallow-lacustrine environment dominated byfreshwater gastropods such as Planorbis(pl), Lymnaea(ly) and Bythinia (bt). B: brackishlagoonal assemblage dominated by the euryhaline hidrobiid gastropod Ventrosia ventrosa. C:shell lag deposit over the ravinement surface containing a time-averaged assemblage withfaunal elements sourced from brackish-protected environments (Cerastoderma glaucum (ce),Gastrana fragilis(ga), Loripes lacteus(lo), Bittium reticulatum (bi)) and open-marineshoreface (Glycymeris insubrica (gl), Chamelea gallina(ch), Chlamys glaberetc.).
pl
plly
bt
bt
ly
lo
ce
ce
cece
bi
bi
lo
lo
lo
lo
lo
glgl
gl
ce
ch
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chCA
B
1 cm1 cm
1 cm
LIA
older deposits(pre mid-Holocene)
mid- late-Holocene
mfs
Little Ice Age
HS
T
mfs
mfs
mfs?
mfs
LIA
LIA
LIA
5
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SCARDOVARI-1
mfs
m
2 m
14ß
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13ß
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00
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0
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0
Venice
Ancon
a Bari
Po rive
r
Trem
iti Is.
Ortona
Garga
no P
romon
tory
P.Penna
Vieste
km0 50Italy N
430 10 20 30 40 50
HST thickness in millisec
Adriatic Sea
CSS00-7
AMC99-7AMC99-9
RF93-30
AMC99-16CSS00-14
RF95-13CSS00-5CSS00-23
AN97-15CM95-33
SCARDOVARI-1
AN97-2
SVAVAM?
AV
6255-6086
3763-3562
6260-6081
1777(1687)1581 yr BP
6611(6498)6426
566(528)498
705-580
1271-1123
626(556)525
14C AMS range age in calibrated yr B.P.
Tephra layers: SV = Somma Vesuvio (1.9 cal. kyr BP)AV = Avellino (3.7 cal. kyr BP)AM = Agnano Monte Spina (4.4 cal. kyr BP)
460(422)330
813(751)700
3262(3204)3137
5567(5485)5449
749(721)658 yrBP
9469(9402)9282 yrBP
0100200300400
CSS00-7AMC99-7CSS00-14RF93-30
RF95-13CSS00-5AN97-15
CSS00-23
55 m 55 m 82 m 77 m 77 m 86 m 65 m 92 m0
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CM95-3334 m
magneticsusceptibility(10-6 SI)
AN97-2
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100200300
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0
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45
ITALY
Adriatic Sea
N
Fig. 27 - Distribution of late-Holocene prodelta deposits on the Adriatic shelf, based onseismic stratigraphy and core correlation (whole-core magnetic susceptibility,biostratigraphy and tephra analysis). These prodelta deposits are distributed along thewestern side of the Adriatic basin in response of ocation of main fluvial sources and thedominant geostrophic gyre. The gray pattern above denotes the deposits that record the lastfew centuries since the onset of the Little Ice Age (LIA, 1450-1880 AD), cold spell. The LIAis the interval when the modern Po delta formed as a supply-dominated system undercombined climatic and anthropogenic forcing. The EU-funded EURODELTA project isextending this kind of studies to more recent intervals and other Mediterranean and Black Seaprodelta stratigraphic archives.
