13
E. Appendices Saska1chewan Geological Survey 217
E. Appendices
Saska1chewan Geological Survey
217
Summary of Investigations 1997
218
.. , .. • . · -· .. - ... --- -·-·-· - -····· ,.
Titles and Abstracts of Recent Saskatchewan Energy and Mines Publications and Papers by Staff of the Saskatchewan Geological
Survey
l. Miscellaneous Reports
Bennett. R. W. ( / 997): Assessment Work Catalogue, Saslwtchewa11; Sask. Energy Mines, Misc. Rep. 97-5. 7/p. .
2. Open File Reports Smith, M.G. and Bustin, R.M. ( 1997): Regional
sedimentology and stratigraphy of the Upper Devonian and lower Mississippian Bakken Formation, Williston Basin; Sask. Energy Mines, Open Vile Rep. 96-1, 20p.
3. External Papers (Saskatchewan Energy and Mines staff arc indicated by bold type fat:c)
Ashton, K.E. and Froese, £. ( 1996); Fe/sic volcanic m cks and hydrothermal alteration in highly metamorphosed parts of the Flin Flon volcanic belt; Min Expo '96 Symposium: Advances in Saskatchewan Geology and Mineral Exploration, Nov. 21-22, Saslwtoon, Prog. Abst., p/8.
In the amphibolitc facies terrains north of Flin Flon, the Flin Flon volcanic belt is represented both as continuous extensions (e.g. the Wildnest-Mirond and Kisseynew lakes areas) and more isolated occurrences (e.g. Sherridon and Scimitar Lake areas). In the absence of primary features, it has generally been assumed that the fel sic gneisses in these terrains were deri ved from plutonic or sedimentary precursors. However, the composi ti on of many of these felsic gneisses could al so indicate volcanic protoliths, and the spatial association of intermediate to mafic gneisses, amphibol ite. VMS-type sulphide minerali zation (e.g. Sherridon. FON, Teejay, and DRS deposits) and metamorphosed hydrothermal alteration supports a volcanic origin.
Four alteration types are recognized: calcic (clinopyroxene. epido1e, calcite). fcrromagncsian (cordierite, garnet, orthoamphibole, cummingtonite). potassic (muscovite. biotite). and aluminous (aluminum si licates). Several of these commonly occur together (e.g. at Sherridon and Wildncsl Lake), which allows easy recognition of potenti ally mineralized areas. The association of altered rocks with felsic gneisses and amphiboli tes is particularly interesting and should act as an incentive for more detai led exploration of these high-grade terrains.
Ashton, K.E., Hartlauh, R.P., and Lewry, J. F. ( /997): Boundary relationships between the Scimitar comple.t and Kisseynew Domain, Tra11.~- H11dso11
Saskatchewan Geological Survey
Orogen, Saskatchewan; GSC Forum /997, Jan. 20-22. Ottawa, Abst. Vol.
The Sdmitar complex comprises volcano-plutonic rocks that have been re-interpreted as part of the Glennie Domain. Most of the boundary between the Scimitar complex and Kisseyncw Domain is irregular due to structural imerdigitation, but not obviously tectonic. The exception is an 8 km section along the southern part of the boundary. where mylonitized rocks appear to represent northern reemergence of the hanging wall of the Pelican Decollemenl Zone, along which Paleoproterozoic rocks of the TransHudson Orogen have been thrust southwestwards over Archean rocks of the Sask Craton. Lithological similarities between the Scimitar and northern Flin Ron (Attitti) rocks imply that they are correlative and continuous beneath the Kisseynew paragneisses. This supports the idea of a Paleoproterozoic protocontinent whit:h stretched from the present eastern Flin Flon Domain to the western Glennie Domain.
Ashton, K.E. and Lewrv, J.F. ( 1997): Geological history of the northern Hanson Lake Block and age relationships between the Pelican Decollement Zone and Sturgeon-weir Shear Zone; LJTHOPROBE Trans-Hudson Orogen Transect, Rep. 55. p73-8/.
Ashton, K.E., Macdonald. R .. Slimmon, W.L, and Lewry. J.F. ( /997): A new compilation of the northwestern NATMAP area, Trans-Hudson Orogen, Saskatchewan; GA C!MAC Annual Meeting, May /997, Ottawa, Abst. Vol., v22, pA-5.
The NATMAP area of the Trans-Hudson Orogen in northern Saskatchewan comprises three main packages of rocks: l ) >2.45 Ga Jan Lake Complex exposed in the Pelican Window, 2) l . 92- 1.83 Ga volcano-plutonic rocks of the Flin Flon-Glennie complex, and 3) l .85-1.83 Ga Bumtwood wackes and Missi conglomerate-arkose sequences. most of which are exposed in the Kisseyncw Gneiss Belt.
The Jan Lake Complex includes pelitic migmatites. >3. l Ga gncissic lcucogranodiori te-tonalites and an intrusive 2.5 Ga charnockite-enderhite suite, which collecti vely represent a rare exposure of the seismically proliled Sask Craton. Rocks of the Pelican Window arc overthrust along the 5-10 km wide Pelican Dernllemenl Zone by the Flin Flon--Glennie Complex, which incorporates tectonically amalgamated 1.92- 1.87 Ga island arc, back arc, and ocean floor volcanic rocks (e.g. Amisk Collage at Min Flon), and 1.87-1 .83 Ga subduction-re lated granodioritic to tonalitic intrusions of the Flin Flon and Glennie domains.
The absence of evidence for either an unconformable or uni versally sheared contact between rocks of the Flin RonGlennie Complex and Kisseynew Domain suggests nearcontinuous deposition of pelit ic sediments from 1.88 synvolcanic argillites to 1.83 Ga hasinal wackes of the Hurntwood Group. Alluvial-shallow marine arkoses and
219
conglo_mcrares of the 1.85- 1.83 Ga Missi Group uncontormably overlie rocks of the Flin Flon-Glcnnie Complex and arc locally facies equivalents of the Burnt wood Group.
Metamorphic grade generally increased northward from greenschist-lowcr amphibolite fades (-450-600°C. 2.8-5.5 kb) in the southern Flin Flon and Hanson Lake areas to upper amphiholitc facics (-600-700°C, 5-7 kb) wndit ions in the north. A metamorphic culmination in the vicinity of the Pelican Window(> 725°( , 6-7 kb) mimics the regional domal geometry and is attributed to late regional folding. Andalusite-. and staurolite-bearing assemblages define a metamorphic low along the Tabbernor Fault Zone.
Collision with the Sask Craton at about 1.83 Ga resulted in southwcst-vcrgent ovcrthrusti ng of the Flin Flon-Glcnnie Complex and structurally overlying rocks of the K isseynew Domain. Subsequent phases of north- and northeast-trending regional folding result from initial collision of the Superior Craton and_ subs~quent related shortening. The extent, depth, and longevity ot deformation suggests that the Tabhcrnor Fault Zone began a.~ a transform fault which continued to focus deformation during collision of the Sask and Superior cratons.
Delaney, G.D. ( 1996): Gold in the Glennie Domain: Relationship to a major temporal break in the supracrusta/ succession: MinExpo '96 Symposium: Advances in Saskatchewan Geology and Mineral Exploration, Nov. 21-22, Saskatoon, Prog. Abst., p21.
The Glennie Domain of the Trans-Hudson Orogcn. nonhcm Saskatchewan, contains in excess of eighty gold occurrences and one gold producer, the Seabee mine at Laonil Lake. Nearly all occurrences arc within or adjacent lo grcens_tonc belts; hy far the greatest number of showings, including the Seabce orcbodics, are hosted in the Pinc Lake Grcenstone Belt. Gold-quartz veins occur in shear zones in a variety of rock types including volcanics. volcaniclastics, sediments, intrusions (both subvolcanic and younger postvolcanic suites). and migmatites. They are also in close spatial association with a major stratigraphic break that separates two distinct assemblages of supracrustal rocks and two major suites of intrusions. The older supracrustal assemblage, which is commonly more volumetrically extensive, consists of ca. 1890 Ma mafic to intermediate volcanic, volcaniclastic, and subvolcanic intrusive rocks emplaccd in anomalous island arc settings. The older suite of intrusions comprises granodioritic and tonalitic plutons emplaced between 1846 and 1859 Ma. The younger supracrustal assemblage is a ca. 1840 Ma succession of volcaniclastic, sedimentary, and minor intermediate to fclsic volcanic rocks, which at least locally are overlain hy a thick sequence of arkose, grit, and conglomerate. A second, volumetrically more restricted suite of granodioritic to granitic intrusions were emplaccd between 1828 and 1836 Ma.
Gold mincrali7 at ion occurs in secondary or tertiary shear zon_es typically developed in areas of lithologic heterogcnity dunng 02 regional deformation. Gold is associated wirh quanz veins, alteration phases. and su lphide minerals and is paragcnelically late. 03 and/or 04 deformation events and syn- to post- 0 3 amphibolite facies metamorphism arc superimposed.
Delaney, G.D. ( 1997): The stratigraphic context of base metal mineralization in Paleoproterozoic
220
sedimentary rocks <>/ the Wollasron Domain, Saskatchewan; GACIMAC Annual Meeting, May 1997, Ottawa. Abst. Vol.. v22. pA-37.
The Wollaston Domain. on the southea.~t side of Hearne Province. is a 430 km long by 45 km wide northcasttrending, generally tightly folded linear belt of Paleoproterozoic supracrustal rocks segmented hy intcrfoldcd Archean granitoids including the up to 12 km wide and over 300 km long Johnson Rivt:r lnlicr along the southeast side of the domain. Throughout much of the domain the Palcoprotero1.oic supracrustal s comprise a hasal pclitic assemblage overlain by a thick succession of arkoscs and calcareous arkoses that contain calc-silicate lemcs. Locally, along the southeast side of the domain, such as in the Courtenay u1kc-Cairns Lake Fold Belt on the southeast side of the_Johnson R_ivcr Inlier, arc unique assemblages, dcposHed m a nit setting. that include conglomerates. quartzllcs, marble. graphitic pelitcs, and rare volcanics of continental tholciitic affinity.
Although exposure is generally poor and the domain has received relatively scant exploration attention. several si_gniticant sediment-hosted base metal showings have been discovered. These include Ph/Zn mineralization hosted in q_uarttites in the basal 'pcli tic' unit at locations along both sides of the Archean Johnson River In lier and the sandstonchosted George Lake deposit, in the Courtenay Lake-Cairns Lake Fold Belt, which contains about 5 million tonnes of 2.65 percent Zn and 0.35 percent Pb. In addition, approximately 25 km southwest of the Johnson River Inlier fanglomcrates of the Janice La_kc Formauon and fine grained sediments of the overlying Raluse Lake Formation host several significant Cu-Ag occurrences including the recently discovered Jansem 2 showing from which grab samples contam up to 4 percent Cu and I oz/ton Ag from a 325 m long by 40 m wide mineralized zone.
. . . Base metal occurrences can be grouped into a few diHerent deposit-types, each formed at a distinct stage in basm cvoluuon and at locations determined by hasin architecture. For example. sandstone-hosted Pb-Zn occurrences arc located in depositional emhaymcnts developed on peneplaincd, weathered Archean granitoid tcrranc. In contrast, red bed type Cu-Ag mineralization in the Janice Lake area occurs in fanglomcratcs and overlying tine grained sediments deposited in a localized extensional depression adjacent to a major rift. Recognition of the stratigraphic control of the various types of sedi ment-hosted base metal occurrences enables exploration activities in the Wollaston Domain to he focused.
Delaney, G.D. ( 1997): The strarigraphic context of base metal mi11era/izario11 in Paleoproterowic sedimentary rocks of the Woltaston Domain. Saskatchewan; I 997 Annual PDA C Convemion March 9-12, Toronto, Open Forum. . '
The Wollaston Domain, on the southeast side of Hearne Province, is a 430 km long hy 45 km wide northeas1-trending, generally tightly folded linear belt of Paleoprotcrozoic supracrustal rocks and although exposure is generally poor and the domain has received relatively scant exploration attention, several significant sediment-hosted base metal showings have been discovered. These include the George Lake deposit. which contains ahout 5 mi ll ion tonnes of 2.65 percent Zn and 0.35 percent Pb and Cu-Ag occurrences in the Janice Lake area including the recently discovered Jansem 2 showing from which grab samples
Summary of lnveJtiMmions /997
contain up to 4 percent Cu and I odton Ag from a 325 m long hy 40 m wide mineralized zone.
Base metal occurrences can he grouped into a few different deposit types. each formed at a distinct stage in basin evolution and at locations determined by basin architecture. For example. sandstone-hosted Ph-Zn occurrences arc located in depositional embayments developed on pencplaincd . weathered Archean granitoid tcrranc. In contrast, red hcd-type Cu-Ag mineralization in the Janice Lake area occurs in fanglomeratcs and o verlying fine grained sediments depos ited in a localized extensional depression adjacent to a major rift. The stratigraphic control of tht: vari ous types of sediment-hosted base metal occurrences enables exploration activities in the Wollaston Domain to he focused.
Haid!, F.M., Bezys. R.K. . and McGregor. C.K. ( 1997): NATMAP Shield Margin Project: Geology of Paleozoic and Mesozoic strata, east-central Saskatchewan and west-central Manitoba; GACIMAC Annual Meeting. June /997, Ottawa, Ahst. Vol.. v22, pA-60-6 1.
Tht: Paleozoic and Mesozoic succession in the NATMAP Shield margin study area comprises primarily Ordovician and Silurian rocks and. in the southwestern corner. Devonian and Jura-Cretaceous strata. The Lower Paleozoic consists of a basal elastic formation ( Winnipeg) and overlying carbonates (Red Ri ver. Stony Mountain, Stonewall, and Interlake formations). The carbonates, characterized by cyclic sedimentation. were deposited in shallow warm seas that covered much of the North American craton during most of the Late Ordovician and Early Silurian. The Ordovician-Silurian boundary is located within the upper 3 metres of the Stonewall Formation at the Cormorant Hill outlier (Manitoba). on the basis of conodont data provided by GSC Calgary. Correlation of strata in the study area with those in the Hudson Bay Basin indicates continuity of deposition between the two areas.
Middle Devonian sediments (Winnipcgosis and Ashern formations) were probably deposited ove r the entire study area but are preserved only in the southwest. The Ashern Formation, which unconformahly overlies the Interlake. is composed of argillaceous dolostone and dolomitic mudstone, and the Wmnipegosis of rcefal and inter-reefal carbonate strata. Both units were deposited in the Elk Point Basin which stretched from northwest Alberta to North Dakota.
Clastic sediments tentatively correlated with the Success Formation (Jura-Cretaceous) in southern Saskatchewan appear to he preserved in paleovalleys eroded into Ordovician carbonates. At Pincchannel Mossy Ri ver Kimberlit e 678. 6- I 9-60-7W2 in the Stonewall outcrop belt. Red River dolostonc is unconformably overlain by 25 metres of mudstonc and sandstone (Success).
Present-day distribution of Paleozoic and Mesozoic strata can he attributed to minor depositional thinning from south to north . to major erosional truncation associated with several unconformities and to post-Silurian llexuring associated with the Tahbcrnor Fault Zone and the ChurchillSuperior Boundary Zone.
Haid/, F.M-, Dane.wk, E.F.R., and Kreis, L.K. ( 1997):Geology and hydrocarbon potential of lower Paleozoic strata, southeastern Saskatchewan; CSPG-SEPM Joint Convention; June / 997. Cal1<ary, Prof? . AIJSt., pl /9.
Saskatchewan Geolog1Cal Survey
Prolific recent oi l production from Ordovician Red River reservoirs below the Mississippian Midale pool highlights the hydrocarbon potential of lower Paleozoic strata in southeastern Saskatchewan. The Berkley et al Midale 4-2-7- 1 I W2 di scovery well has produced 31,016 cubic metres ( 195.091 barrel s) of oil and only 2 18 cubic metres of water in it s first ten months of production.
Abundant data suggests significant additional o il potential in the Williston Basin lower Paleozoic succession of basal elastics (Deadwood/Earlie and Winnipeg formations) and overlying carbonates and evaporites (Yeoman and Herald formations (Red River); Stony Mountain, Stonewall and Interlake formations). Lack of hydrocarbon shows in the basal elastic unit do not lessen their potential in Saskatchewan. High oil production rates from Deadwood sandswnes near the border, at Newporte Field. North Dakota, good possibility of stratigraphic traps against isolated Precambrian highs, and identification of a unique source for oils produced from Deadwood Formation and other pools, together favour significant potential.
The carhonate-evaporite sequence reflects several depositional cycles, each beginning with marine carbonates and culminating with basin-centred evaporites. To date, only carbonates of the first cycle have produced economically significant volumes of oi l in Saskatchewan. In thi s cycle, burrow-mottled and laminated carbonate reservoirs of the upper Yeoman Formation and the Lake Alma Member, Herald Formation are capped by the Lake Alma Anhydrite. Most oil is trapped in structures related to episodic Phanerozoic movement of Precambrian basement blocks. Rcst:rvoir quality is related primarily to complex dolomitization controlled by several factors. Geochemical studies indicate that oil in the initial carbonate cycle is sourced from Yeoman Formation kukersites.
Petroleum shows are also reported from overlying Ordovician and Si lurian rocks. The most significant Interlake Formation show is from a drillstem test of the upper l I min the MOWS N Redvcrs 14-19-8-32WI well, where 27 m of oi l, 31 m of oil-cut mud, and 37 m of water were recovered. An oi l in an adjacent well suggests that this oil has a source simi lar to that of Interlake pools in the Ncsson Ancicline.
Haidl, F.M., Longman. M. W. , Pratt. B.R., and Bernstein, l.M. ( /997): Variations in lithofacies in Upper Ordovician Herald and Yeoman formations ( Red River), North Dakota and southeastern Saskatchewan; CSPG-SEPM Joint Convention, June / 997, Calgary, Core Conference Proc., p5-39.
The Upper Ordovician Yeoman and Herald formations in Saskatchewan are equi valent to the Red River Formation in the United States and Manitoba portions of the Williston Basin. The Yeoman Formation generally consists of burrowed mudstones and skeletal wackestones lo packstoncs with a marine fauna. In places. it also contains thin, organicrich kukersi tcs (kerogenites) that provided source beds for hydrocarbons. Otl and gas generated in these kukersites are common in structural traps and some stratigraphic traps in the southern and western parts of the Williston Basin, hut only recently have Yeoman reservoirs become a maJor exploration target in the northern pan of the basin.
The Herald Formation conformably overlies the Yeoman Formation and consists of several depositional cycles. In ascending stratigraphic order, these rocks arc represented by the Lake Alma and Coronach members, and the Redvers Unit. The Lake Alma Member consists of laminated
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dolomudstones overlain by bedded to nodular anhydrite reflecting an increasingly hypersaline shallow subtidal environment. The Coronach Member has burrowed skeletal wackestones at the base, laminated dolomite in the middle, and, in the basin centre. bedded anhydrite at the top. It represents another brining-upward sequence. The Redvers Unit. with a lower limestone capped hy laminated dolomite mudstones (and anhydrite in the basin centre). is a third brining-upward sequence.
Facies variations at and near the contact of the Yeoman and Herald fo rmations ;ire focal to this presentation. The nature of hydrocarbon source beds and reservoir facies arc also documented. The cores on display are: I) Total Petroleum #1-25 Alexander (Sec. 25, Tl29N-R I05W ; Bowman County. Nonh Dakota) in South Horse Creek Field: 2) Mark SaskOil Minton 3-17-3-2JW2 in Minton Field, Saskatchewan; 3) LVR et al Steelman 7-28-4-4W2, Saskatchewan; and 4) Cdn-Dev TW Langhank I S-28- I 2-2W2, Saskatchewan. The Alexander and Minton cores show oil-bearing dolomitiled burrowed wackestone typical of reservoir rocks in the upper part of the Yeoman Formation. The Steelman well penetrated an unusual stromatoporoidal bank capped by thrombolitic (microbial) reefal dolostone in the lower Herald Formation. The Cdn-Dev TW Langbank IS-28- l 2-2W2 core reveals a distinctive shallow-water fac ies found towards the basin's ea~tem flank near the limit of Lake Alma anhydrite deposition.
Hajnal, Z., Stauffer, M.R., White. D.J. . Lucas, S. 8., lewn,, J.F. , Clowes, M.R. , and Ashto11, K. E. ( 1997): Three dimensional seismic crustal signature of the western Trans-Hudson Orogen. Saskatchewlln; LITHOPROBE Trans-Hudson Orogen Transect, Rep. 55, pl 13-124.
Lafrance, B. ( 1997): The Parker uike Shear Zone and Reilly lake Shear Zone, Saskatchewan: Products of regional tramposition across the Wathaman Batholith; 7th LITHOPROBE Trans-Hudson Orogen Transect Workshop. May I 997, Saskaroon.
Lafrance, B. and John, B.E. ( 1997): Emplacemem history of the early Prorerowic Gunnison annular complex, SW Colorado; CACIMAC Annual Meeting, May /997. Ottawa, Abst. Vol .. v22, pA-83-84.
The Gunnison annular complex is an early Protero1.0ic, calc-alkaline, dioritic to granitic igneous complex in SW Colorado. The complex was emplaced in bimodal volcanic rocks and metasedimentary rocks of the Cochetopa succession, interpreted as an island arc sequence deposited 1745-1730 Ma year ago. The 4 km wide Gunnison annular complex consists of a central quam. diorite body dated at 1730 ±6 Ma, a metasedimentary and amphibolitic inner ri ng (the Cochetopa succession), and a tonalite/granodiorite/ granite outer ring dated at 1721 ± 7 Ma ( U/Pb zircon ages). The complex has a concave upwards geometry with concordant inwards-dipping contacts between intrusive units and country rocks. The central quanz diorite body and outer ring intrusions are intc'l)retcd as the central stock and cone sheets. respectively, of a deep-seated ring-dyke complex.
Detailed mapping suggests that the geology of the complex is not compatihle with a ring-dyke model. The central quam. diorite body was emplaced by lit-par-lit injections of quanz diorite ~ills parallel to bedding. During
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regional deformation, the quam diorite sills were fo lded into an upright n:gional fold. During a later stage of the same regional deformation. the fo ld and country rocks were transposed against the central quartz diorite body. producing an arcuatc foliation parallel to the margins of the intrusive body. Granite, grano<liorite. and tonalite intrusions were then emplaccd as dykes parallel to the arcuate foliation. forming an outer ring intrusive unit with concordant inwards-dipping contacts with the country rocks. Diverse overprinting relationships ~uggest that this transposition event and emplacement of the outer ring intrusions occurred during the development of a regional NW-trending fo liation. which overprints regional folds elsewhere in the area.
Plutonic annular complexes are interpreted as the root 1.0ne~ of subvolcanic ring-dyke complexes. This study shows that emplacement mechanisms of annular plutonic wmplexes arc strongly dependent on the geometry and style of the regional deformation, as is the case fo r deep-level granitic plutons and batholiths.
Lucas, S.B .. Stem, R.A., Ashton, K.E., Syme, E.C., A11sde/l, K.M. , and Lewry, J.F. (1996): Regional tecto11ic setting of the 1.9 to 1.8 Ca Fli11 Firm Belt in the Trans-Hudson Oroge11, Saskatchewan and Manitoba : Min£xpo'96 Symposium: Advances i11 Saskatchewan Geology and Mineral Exploration. Nov. 21-22, Saskatoon, Prog. Abst., p33-34.
The Reindeer Zone. Trans-Hud~on Orogen (THO). has long been considered a type example of juvenile cnistal addition and net crustal growth during the Paleoprotcrozoic. The record of mantle melt extraction in the areally extensive Reindeer Zone spans 90 Ma ( 1.92-1 .83 Ga). with relatively little evidence for recycling of Archean crust (i.e. >95% isotopically-juvenile crust). Although the juvenile crust now forms a carapace of thrust imhricates above an Archean tcrranc that was underthrust during 1.84-1.80 Ga collisional tectonics, ~tudy of low strain-domains such as the Flin Flon Belt has unraveled a ponion of its pre- 1.84 Ga history.
Through an integrated geological mapping and thematic research program. the NATMAP Shield Margin Project has shown that the Flin Flan 'greenstonc' belt comprises 1.92-1.88 Ga tectonostratigraph ic assemblages derived from a variety of tectonic environments and amalgamated to form an accretionary collage prior to the emplacement of 1.87-1 .83 Ga granitoid plutons. Four main tectonostratigraphic as~emblagc types are recognized: isotopically-juvcnile oceanic arc ( 1.90-1.88 Ga). ocean floor (ca. 1.90 Ga). oceamc plateau/ocean island, and isotopically-evolved arc.: ( 1.92- 1.90 Ga). Early (ca. 1.90 Ga) tholeiitic arc sequence~ were rifted. creating intra-arc basins in which oceanic basalts, turbrditcs and calc-alkaline and shoshonitic.: volcanicla~tics accumulated at 1.89-1.88 Ga. Significant (30-40%) recycling of Archean crust is requi red only for the evolved arcs, which arc a minor component of the collage. The tectonoMratigraphic.: assemblages were juxtaposed in an m:cretionary complex (Amisk collage) at ca. 1.88-1.87 Ga. probably as a result of arc-arc collision(s). Accrctionary collage structures arc largely obliterated by subsequent deformation and metamorphic events. but can he inferred where cut by c.:alcalkalinc plutons related to a 1.87-1.84 Ga arc. Coc1•al subacrial voll:anism is recorded in ca. 1.87- 1.85 Ga calcalkalinc to shoshonitic volcaniclastic sequences. The plutons and coeval volcanic rocks are associated with younger arc{s) imposed on the collage as a result of progradation of the arctrench ~ystem through the accrctionary colh1ge or a subduction polarity reversal. Unroofing of the collage to erode post-accretion plutons, development of a paleosol, and deposition of continental (alluvial-tluvial) scdiml!ntary rocb
S11111111ary vf lnves1igutions /997
occurred ca. 1.85- 1.84 Ga. coeval with the waning stages of post-acccretion arc magmatism. The Flin Flon Be lt had evolved to the stage of a Philippines- or Japan-like microcontinent by 1.85-1 .84 Ga, although it probably represents only part of such a microcontinent. with the rest found in adjacent domains (Hanson Lake Block, Glennie Domain). Regionally extensive turhidites were deposited in the Kisseynew 'basin' (back-arc basin'l) at 1.85-1.84 Ga, contemporaneous with continental sedimentation in the Flin Flon Belt. The turbidites, which may have been derived from mountain belts arising from a numher of colli sions, occurred in the interval 1.86-1 .85 Ga across the Trans-Hudson Orogen.
The Flin Flon Belt experienced protracted intracontinental deformation following the cessation of arc magmatism at ca. 1.84 Ga. A bell of mafic to felsic. calcalkaline volcanic and plutonic rocks developed at I .84-1.83 Ga in crust that now structurally overlies the Amisk collage (south flank of the Kisseynew Domain). This magmatism was coeval with both early thrusting of Kisseynew Domain turbidites on the Amisk collage and with continental (foreland basin?) sedimentation. The Amisk cu llage is bound hy major collisional thrust structures, including the Morton Lake thrust zone, the Sturgeon-weir Shear Zone and a system of southwest-vergent thrusts carrying allochthons of 1.85-1.84 Ga turbidites (south flank of the Kisseynew Domain). These structures appear to root into the Pelican decollement, which separates juvenile crustal allochthons (Hanson Lake Block) from underlying Archean basement. Seismic reflection images of Reindeer Zone crustal structure provide a means of determining the fate of the juvenile m1crocontincntal terranes (e.g., Flin Flon-HansonG!ennie) following terminal collision with Archean blocks/cratons at ca. 1.84-1.80 Ga. During coll ision. the juvenile microcontinents were sliced into 10-15 km thick imbricates and juxtaposed between Kisseynew Domain allochthons and undcrthiust Archean basement. Delamination ('flaking') of the juvenile terranes at the Moho or within the lower crust is suggested by the juxtaposition of Proterozoic crustal units on Archean basement, as observed at the tectonic windows through the Reindeer Zone allochthons and inferred from the seismic images.
Lucas, S. B., Stern. R.A., Syrne, E.C., Zwanzig, H. , Bailes. A.H., Ashton, K.E., Maxeiner, R.O., Ansdell, KM., Lewry, J.F .. Ryan, J.J., and Kraus, J. ( /997): Tectonics of the southeastern Reindeer Zone, Trans-Hud.rnn Oro gen ( Manitoba and Saskatchewan); GAC/MAC Annual Meeting, May 1997, Ottawa. Ahst. Vol., v22, pA-93.
A new tect0nic framework for southeastern Reindeer Zone of the Trans-Hudson Orogcn (THO) has emerged in recent years through four-dimensional studies (bedrock & subsurface mapping, seismic reflection profiling, U-Pb geochronology) associated with the NATMAP Shie ld Margin Project and LJTHOPROBE THO Transect. This part of THO is marked by a northeast -dipping, crustal-scale stack characterized by three principal e lements which were juxtaposed during 1.84-1 .80 Ga colli sional deformation: (I) 3.20-2.40 Ga metaplutonic rocks and paragncisses of the Sask craton, exposed in the Pelican window; (2) 1.92-1.87 Ga juvenile arc and oceanic rocks, 1.88-1.84 Ga plutons, 1.87-1.85 Ga volcano-sedimentary packages (SchistWckusko assemblage) and 1.85-1.84 Ga all uvial -lluvial sandstones (Missi Group); and (3) 1.85-1 .84 Ga marine turhidites (Bumtwood Group) and distal facies of the Missi Group sandstones at the highest structural levels (Kisseynew Domain). The middle element in the stack comprises the Flin Flon Belt (now including the Attitti Block and
Suska1clzewu11 G,•oioMiClll Survey
Paleoproterozoic rocks in the Hanson Lake Block) and Glennie Domain (including the Scimitar Complex) and is here termed the Flin Flon- Glennie Complex (FFGC). The existing stratigraphic framework for Flin Flon Belt greenstones (Amisk Group) is insufficient to account for the range in lithological and geochemical associations. Sm/Nd i5otopic signatures and U-Pb 2.ircon ages. As a result, a series of I .92- 1.87 Ga arc and ocean floor assemblages have been distinguished. These assemblages are stitched together by crosscutling plutons ( 1.88- 1.84 G a) and some are separated hy early high-strain zones, suggesting that they were accreted to form a tectonic collage at 1.88-1.87 Ga. Post-accretion plutons and volcanic rocks ( 1.88-1 .84 Ga) are attributed to younger arc(s) imposed on the collage (successor arcs), which developed contemporaneously with regional steepening of the early collision-accretion structures. Uplift and erosion, development of a paleosol and deposi tion of voluminous turbidites (Burnt wood Group) and continental sedimentary rocks (Missi Group) occurred ca. 1.85-1.84 Ga. coeval with the waning stages of successor arc magmatism.
Assembly of the crustal thrust stack occurred in response to collision of the Sask craton with the overridi ng FFGC. Due to structural interleaving, the boundary between the FFGC and Kisseynew Domain is best described as a structural-stratigraphic transition zone. In contrast. the boundary between the Sask craton and FFGC is a broad ductile shear zone termed the Pelican dceollement zone. Initial thrust ing was coeval with 1.84-1 .83 Ga mafic-fclsic calc-alkalinc magmatism and ongoing continental sedimentation (Missi Group), and continued through peak regional metamorphism at 1.82- 1.80 Ga. Oblique collision with Superior craton occurred at about I .81 Ga and led to post-collisional sinistral transpression of eastern THO. with wrench faulting and refolding of the thrust stack producing considerable structural relief.
Maxei11er, R.O. and Sibbald, T.l.l. ( /996): Redefining contact relationships between Mclennan Group and surrounding fithotectonic elemems in the southern La Ronge Domain, Trans-Hudson Oroxen - Saskatchewan; MinExpo '96 Symposium: Advances in Saskatchewan Geology and Mineral Exploration, Nov. 21-22, Saskatoon. Prog. Ab.st., p35.
The McLennan Group, a lithotectonic element of the La Rongc Domain, has t raditionally been viewed as a molasse deposit lying unconformably upon rocks of the Central Meta volcanic Belt (CMB) and the Maclean Lake Belt (MLB). Structurally it lies between these two nonhwest dipping hefts. and is overthrust along much of its length by the CMB along the McLennan Lake Tectonic Zone. At the south end of the domain, the exposed relationship between McLennan Group and CMB is clearly interpreted to be an unconformity.
Based on recent remapping of parts of the region. two typically di stinct supracrustal assemblages are recognized. Assemblage A (>ca. 1855 Ma), a predominantly volcanoplutonic assemblage that is exclusively made up of CMB rocks. comprises mafic to intermediate and minor felsic volcanics which are intruded by si mple to multiphase plutons. Assemblage B (:5 1855 Ma) is formed by polymictic volcanogenic conglomerate. psammite, calcareous psammite, psammopelite, trachytic-tcxtured intermediate volcanics. amphibolitc and arkosic rocks including those of the McLennan Group. It is intruded by quartz-phyric granite porphyry, mane to felsic dykes and sills, and multiphase granites. The basal parts of Assemblage B arc characterized by a heterogeneous volcano-sedimentary succession that is
223
gradational into and intercalated with overlying McLennan arkoses and arkosic conglomerates. Local unconformity exists between quanz-phyric granite porphyry. which intrudes polymictic volcanogenic conglomerate and overlying McLennan arkose. and arkosic conglomerate. However. major regional unconformity exists between A~semblage A and Assemblage B.
The basal. heterogeneous pan of As~emhlagc B is of economic interest because it contains a diversity of gold occurrences which differ markedly from the shear zonehostecl deposits of the CMB. Examples of such occurn:nces are provided by showings at Grcywacke Lake, Rarnsland Lakes. and Nonh Lake. The extended package of ca. 1840 Ma to 1855 Ma supracrustals. overlying the CMB and the similarly aged 'auriferous' volcano-sedimentary package now identified throughout the Glennie Domain. clearly represent a mcrnllotcct that has been underexploited because of a lack of deposit models.
Maxeiner, R.0. and Sibbald, T./.1. ( / 9(}7): Redefining comact relationships between Mcl ennan Group and surrounding lithotectonic elements in the southern La Ronge Domain, Trans-Hudson Orngen, Saskatchewan; GSC Forum / 997, Jan. 20-22. Ottawa, Abst. Vol.
Recent mapping of parts of the southern La Ronge Domain has distinguished supracrustal assemblages of two ages. Assemblage A (>ca. 1855 Ma), a predominantly volcano-plutonic as~emhlage that is exclusively made up of Central Metavolcanic Belt rocks, comprises mafic to intermediate and minor fclsic metavolcanic and some metasedimentary rocks intruded by simple to multiphase plutons. Assemblage B (<1855 Ma). predominantly a mixture of psammitic to arkosic metasediments, includes rocks of the McLennan and Maclean groups. It is intruded by quartz· phyric grani te porphyry, mafic to felsic dykes and sills. and multiphase granites. The basal pans of Assemblage 8 arc characterized by a polymictic metaconglomerate overlain by a heterogenous volcano-sedimentary succession that is gradational into and intercalated with overlying McLennan meta-arkoses and arkosic mciaconglornerates. Local unconformity exists between quartz-phyric granite porphyry. which intrudes the polymictic rnetaconglornerate. and the overlying McLennan arkosic rnetaconglornerate and mctaarkose. However. a major regional unconformity exists between A~semblagc A and Assemblage 8.
Maxei11er, R.O. and Sibbald, T./.1. ( /997): Redefining contact relationships between McL ennan Group and surrounding litlwtectonic elementl· in the southern La Ronge Domain, Trans-Hudson Orogen - Saskatchewan; L!THOPROBE TransHusdo11 Orogen Transect, Rep. 55, p4.
The McLennan Group. a lit hotectonic clement of the La Ronge Domain, has traditionally been viewed as a molasse deposit lying unconforrnably upon rocks of 1he Central Metavolcanic Bell (CMS) and the Macl ean Lake Belt (MLB). Structu rally it lies between these two northweM di pping belts. and is ovcnhrust along much of its length by the CM B along the McLennan Lake Tectonic Zone. Only at the south end of the domain is the exposed relationship between Ml'Lennan Group and CMB interpreted to he an unconformity.
Based on recent remapping of parts of the region. two typically di stinct supracrustal assemblage~ are recognized. Assemblage A (>ca. 1855 Ma). a predominantly volcano-
224
plutonic as~emblagc that is exclusively made up of CM 8 rocks, comprises malic 10 intermediate and minor frbic volcanics which are intruded by simple to mult iphase plutons. Assemblage B (~ 1855 Ma) is formc:d by polymictic volcanogenic conglomerate. p~ammite. calcareous psammite. psammopelite, trachytic-tcxtured intermediate volcanics. amphiholitc and arkosic.: rocks including thos.: of the McLennan Group. It is intruded by quartz-phyric granite porphyry, maflc to fclsic dykes and ~ills, and mult iphase granites. The basal parts of As~emblage 8 arc characterized by a hctcrogcnous volcano-sed imentary succe~sion that is gradational into and intercalated with overlying McLennan arkoscs and arkosic conglomerates. Local unconformity ex ists between quartz-phyric granite porphyry, which intrudes polymictic volcanogenic conglomerate and overlying McLennan arkose. and arkosic conglomerate. However. major regional unconformity exists between Assemblage A and Assemblage B.
The basal, heterogeneous part of Assemblage B is of economic interest because ii contains a diversity of gold occurrences which diffe r markedly from the shear 1.onehostcd deposits of the CMB. Examples of su.:h occurrences arc provided by showings at Greywacke Lake. Ramsland Lakes, and North Lake. The extended package of ca. 1840 Ma to 1855 Ma supracrustals. overlying the CMB and the simi larly aged aurifcrous volcano-sedimentary package now identified throughout the Glennie Domain. clearly represent a metallotect that has been underexploited because of a lack of deposit models.
Roherts, C.R. and Maxeiner, R.0. ( 1996): The Anxlo Rouyn L>eposit, La Rmzge. Saskatchewwr: A volcanogenic massive sulphide deposit; Saskatchewan Geological Society MinExpo '96 Symposium: Advances in Saskatchewan Geology and Mineral Exploration, Nov. 21-22, Saskatoon, Prog. Ahst., p39.
The Anglo Rouyn deposit is on the northwest shore of Lac la Runge approximately 35 km northeast of La Rongc. Saskatchewan. Betwc:en 1966 and 1972. Rio Alcorn Mine~ extracted 1.7 million tonnes of ore from three oichodics wi1h an average grade of 1.7 percent Cu. 1.2 g/1 Au. and 5.5 git Ag.
The property is underlain by a northeast-trending belt of amphibolitc fades. gnei~sic roch within the Nut Bay Belt, a subdivision of the La Ronge Domain. The ~tratigraphic sequence on the mine property. from bottom to top. (or southeast to nort hwest) is as fo llows: (i) basalt tl ows and tuffs (homblendc-plagioclasc schists) interlaycrcd with th in units of quam.-biotitc schist: (ii) carhonate-amphihole· plagioclase gneiss (subordinate: scapolitc. diopsidc. quanz, epidote, biotitc); (i ii) magnetitc:-homblendc-plagioclase gneiss (subordinate: calcite, quanz. epidote. diopsidc. chalcopyrile. iron sulphides). which. is slratigraphi.:ally equivalent to amphibole-plagioclase gneiss in the we~tcrn pan of the propeny: (iv) the ore bearing unit of quam.homblcnde-plagioclasc gneiss (subordinate: diop~idc. epidote. biotite. scapol itc, calcite. sphencl: (v) the h.ingingwall unit or quanz-plagioclase gneiss (~uhon.lina1e: hiotile, microcline. diopsidc, cpidote. hornblende. calcite. scapolitc, grossular garnet, sphene). The hanging-wall unit is in intrusi ve contact with granodiorite and granite of the Jepson Lake pluton. The gneissic layering (S I) is formed hy the transposi1ion of sedimentary layering SO. The SO/S I relationships demonstrate that gnci~sic rocb of the mine area are at the south limb or a synform and the stratigraphic relationshi ps suggest that the units face to the non h.
S11111111ary of /111•,,.Hifiatio11.1· 1997
The orebodies arc s1ratabound. with in the quart1.hornhlcndc-plagioclasc unit , and cons ist of "rule r- shaped" lenses o f su lp hides (chakopyritc, pyrite . pyrrhotitc, magn etite. and !race amounts o f sphalcritc. mo lybdenite. and skuttcruditc). di stributed over a strike length of :moo m. Primary layering was identifi ed in the ore lenses which plunge at s hallow ang les , parallel to the mineral lincation in the gneissic layering .
F rom a geochemical study of the gneissic and basaltic units. it is conclud ed chat: (i) the hornblcnde-plagioclase gneiss is an immature sediment derived from the weathering of hasalt ; (ii) the mag netite and carbonate-hornblendeplagioclase gneiss units arc simila rly immature sediments with the addition of exhalau ve iron oxide and carbonate ; (i ii ) !he ore host unit cons ists of materia l equ ivalent 10 the amphibole- plagioclasc gneiss unit with the addition of exhalative si lica and !he components of the ore; and (v) the aluminum-rich calc- silicale assemblage of the hang ing wall is the metamorphic eq uivalent of a clay-rich sediment (illi1c. k aolinite . chlorite) that contained cxhala ti ve silica and carbonate.
Sibbald, T.1.1. ( 1996): Nicholson Hay uranium-goldPGE deposits ; Min Expo '96 Symposium: Advances in Saskatchewan Geoh>gy and Mineral Exploratio11, Nov. 21-22, Saskatoon, Prog. Ahst .. p43.
Between 1953 and 1982. the Beaver lodge uranium district produced some 25 000 t of urani um metal fro m 17 main mines. The pro ducing deposits, as well as numerous other radioacti ve showings in the a rea. are predominantly classical epigenetic ve in-type pitchblende occurrences. Most arc hosted by rocks o f the metamorphic h asemcnt although veins a re a lso present in rift-deposited immature elastics and alkalic basalts of the unconfonnably overlying Palcoprotero1.0ic ( 1700 -1800 Ma) Martin Group. Mineralization is al so known in the younger Mesoprotc rozuic ( 1450 -1 700 Ma} matun: sand stones or the Athabasca G roup.
The epigenetic deposits can he divided into two groups, respect ively showing simple and complex mineralogy. In the former. pitchblende is act·ompanied by hranncrite. chalcopyritc, pyrite. galena an d nolanite, and uranium by a simple suite of elements (Cu, Pb, Fe, Y. S ). In the latter. pitchblende and thucholite arc accompanied hy a rsenides, sulphides, selcnides and native metals. and uranium by a diverse group (>f c le ments (Cu, Ni. Co. As. Pb. Fe . V, Y. Se. Ag. Au. PGE).
The association of uranium, gold. and platinum group metal s was first described in 1955. but on ly more recentl y has exploration interest for the precious metals gained importance . Impetus was prov ided hy: I ) discovery o f a potentially economic zone or g old-plati num group metal mincral i1.ation. adjacent to the hi~toril·ally mined Coronation llill uranium-gold deposit. in the South Alligator Ri ver Uranium Field (SA RUF) in the No rthern Territo ry of Austra lia. and 2) n:cognition that Coronation Hill and o ther de posi ts in the SARUF show many similarities of mineralogy and geolog ical setting to complex pitchblende veins in the Beaverlodgc diMricl. T he regional geological analogy is fu rther enh anced hy the undoubled resemblance of the nearby world-class unconformity-type uranium <.kposit s of the Alligator River Uranium Fie ld to those within the Athaha~ca Basin of Saskatchewan . Ex plorat io n around Nichol son has identified. adjacent to hi storic uranium prospects . more extensive zones of gold and platinum group metal m ineralization than previous ly recognized (Nicholson #2
Sa.rka tch1'.11·w1 G,·olo,-:ical Sun ·,·v
zone) and has also resulted in new discoveries (Quartz ite Ridge).
Cry ptic gold and pla tinum group metal mmerali1.ation occurs within alte ratio n zones commonly adj acent to uranium veins of complex mineralogy. These zones are characterized hy : l) hcmati zatio n, si licificatio n. and talc ification of host dolo mitic marbles, dio psidic calc-si licates. and quart1.ites; 2) extensive fracturing ; and 3) development of vugs containing euhcdral quartz. specula r he matite and carbonates. There is a close spatia l rela tionship to the sub-M artin Group and/or sub-Athabasca Group unconfonnities. and detailed field relationships and U/Pb ( pitchblende) age data suggest minerali zation afte r deposition of the Athabasca Group. Preliminary fluid inclusion studies from secondary cuhedral quartz and carbonates from the a lte red/mincra li1.ed zones indicate fluids wi th tem pera tures in the range l 50 -200° C and high salinities. Similar fluids character ize the unconformitytype uranium minera li7.ation of the Athabasca Rasin.
The uranium-gold -platinum group metal deposits of the Beaverlodge distr ict and SARUF represent a new type o f low-temperature, hydrothermal precious metal minera I izat io n. Thei r eco nomic potentia l is as y et unknown, as b the explo ration po tential o f the Paleo - to Mesoproterozoic sandslone basins to which they appear related.
Slimmon, W.L., Maxeiner, R.O., and Reilly, B. A. ( J 997): Bedrock geology compilation of the .wmthwestern NA TMAP Shield Margin Project: Limestone-Ha11.wm-Amisk lakes areas. TransH11dso11 Orogen, Saskatchewan; GACIMAC Annual Meeting, May 1997, Ottawa. Abst. Vol. , v22. pA-139.
The southern ha lf of the e xposed NATMAP Shield Margin Project area in Saskatchewan is predominantly underlai n h y juvenile rocks o f the intraoceanic Fl in FlonGle nnic Complex (FFGC), including areas formerly referred to as Hanson Lake Rlock . Glennie, and Flin Flon domains. FFGC structurall y o verlies 2 .45-3.20 Ga pluto nic and sedimentary rocks o f the Sask Crat0n and is overl a in by 1.85-1.84 fluvial lo marine sedimentary and minor vo lcanic rods of the Ki sscyncw Domain (Burntwood and Miss i Groups).
In the map area. FFGC encompasses two principal upper greenschist to middle arnphibolite facies volcanopluto nic packages with associa ted sedimentary rocks (Amisk Co llage and Hanson Lake volcanic belt) and is separa ted to the north from rocks of the Sask Craton by the Pe lican Dcco llcment Zone . The Amisk Collage comprises 1.92- 1.906 Ga isotopically-evolvcd arc plutonic rocks (Mysti c Lake As.~emblagc) and 1.9 ()4-1 .881 Ga juvenile rocks including : tholeiitic ocean fl oor basal tic fl ows (El bow-Athapapuskow A ssemblage ); tholciitic back-arc or oceanic plateau basaltic flows (Sandy Bay and Muskeg Bay assemblages): tholciitic arc subaqueous basaltic fl ows and volcaniclastic rocks (Flin Flo n and Birch Lake assem blages): tho leiitic arc subaqueous to subacrial basaltic flo w s and volcaniclastic rocks (Crater Island Assemblage); calc-alkalinc arc subacria l to subaqueous fclsic to intermedia te vo lcaniclastic rocks (West Amisk Assemblage); and volcanogenic turh iditcs (Welsh Lake Assemblage). The tcc tonostratigraph ic asse mblages we re amalgamated prior to the emplaceme nt o f 1.8 7- 1.83 Ga cak-alkalinc granitoid pluto ns and arc unconformahly overlain by 1.85-1.84 alluvial-fluvial sedimentary rocks o f the Missi Group.
The Hanson Lake and Northern Lights assemblages of the Hanson Lake vo lcanic bell show strong lit hological,
225
geochemical , and geochronological similarities to the Amisk Collage but arc separated from it by a splay of the Pelican Decollement Zone. At Hanson Lake, subaqueous to subaerial matic 10 felsic volcanic rocks (ca. 1.875 Ga) are overlain by a greywacke-dominated sedimentary sequence. The volcanic sequence shows evolution from primitive arc tholeiites to evolved calc-alkaline island arc rocks and is intruded hy younger subvolcanic alkali ne porphyries: syn vo lcanic_ calcalkaline granites ( 1.873 Ga) and composne calc-alkahne plutons ( I .844-1 .843 Ga). T he Northern Lights Assemblage includes tholeiitic arc pillowed mafic flows, fe lsic to intermediate volcaniclastic rocks and associated greywackes , and appears to be stratigraphically equivalent to the lower portion of the Hanson Lake Assemblage.
Tisdale. D .. Delaney, G.D., and Ansdell, K. ( 1997): Paleoproterozaic iron formation of the Co urtenay Lake- Cairns Lake Fold Belt, Wollaston Domain. Saskatchewan. and potential for base metal mineralization; GAC/MAC Annual Meeting, May 1997, Ottawa, Abst. Vol. , v22. pA-148.
The Courtenay Lake- Cairns Lake Fold Belt, along the southeast side of the Wollaston Domain, comprises a northeast-trending thick succession of Paleoproterozoic siliclastic and minor carbonate and volca nic rocks deposited in a narrow restricted rift basin. These rocks contain the George Lake Pb-Zn occurrence as well as o ther anomalous concentrations of base metals. The uon formallon discussed here will be examined in order to assess its relationship to the base metal occurrences.
The iron formation, which forms part of the Spence Lake Formation near the top of the succession, has been deformed into three tight southwest-trending folds in the closure of a major synform and has a strike extent _of at least 35 km. Two facies are identified ; an oxide and a s1hcate facies, which together are about 15 m thick. The silicat~ facies , which is in gradational contact with the underlying layered gametiferous pelite unit, comprises fine grained buffpink weathering gametifcrous calc-silicate layers and more green-grey weathering thinner layers richer m calc-stl_1cate minerals. The oxide facies is characterized by rhyth micall y alternati ng mill imetre -thick dark grey weathering magnetite laminae and grey to light grey lamin_ae composed . predominantly of chert. The two fac1es grade late:all y mto each other. Geochemically the two fac1es are d1stmct when compared with their counterparts in Algoma m Supcnor t)'.pe iron fo rmations. In parti cular the Spence Lake iron formation has high concentrations of Mn.
Some investigators have suggested that the ir~m . . formation member of the Spence Lake Formation 1s s1m1lar to Mn-rich iron formations associated with Pb-Zn mineralization in the Broken Hill area of Australia . Although preliminary electron microprobe ~ata reveals the Mn_coment of garnets from the Spence Lake iron formation a_re s1 m_1 Jar w values obtained from analyses of garnets m iron formauon m the Mn enriched zone at Broken Hill , there are signi ficant geochemical and petrographic differences between iron formations from the two areas . Nevertheless, the presence of this Fe and Mn-rich unit in the Courtenay Lake- Cairns Lake fold belt provides strong evidence for the existence of acti ve seafl oor hydrothermal vents, and thus potential for base metal mineralization.
Viljoen, D., Broome. J., Lenton, P. G .. and Slimmon, W.L ( /997): The role of digital data management in the NATMAP Shield Margin Project;
226
GAC/MAC Annual Meeting, May 1997. Ouaw<i. Abst. Vol., v22, pA -153-154.
The NATMAP program is a multidisciplinary. multiagency program designed to improve geological mapping within target areas in Canada. The 5-year Shield Margin Project, which will end in 1997. covers an area equivalent lo two I :250,000 scale map sheets straddl ing the ManitobaSaskatchewan border. One of the principal ohjectives of the project was to develop a digital geosciencc database for the study area housing both existing and new geoscience data and to develop and apply digital methodology to utilize these data to aid in achieving the geological goals of the project.
The d igital geoscience datahase is the core of the digital initiative. T he database contains all data relevant to the project registered tn a common projecti_on. organi_zed in a way which allows p~rticipants t? co_m,bmc. v1 suall zc_, and analyze data as reqwred. By mamtammg data m d_1g1tal ~orm from the fie ld through to publication, a number ol bcnel1ts can be rea lized.
I. The combination of digital field data and digital cartography allow more efficient production of maps.
2. The database, and database manager, are a convenient source for all data for all participants.
3. GIS-based visualization and spatial analysis techniques encourage integration of geoscience disciplines.
4. T he project database becomes a digital archive at the end of the project which can be published.
A number of digitally-produced products have been released. In I 993. a preliminary CD-ROM was released (GSC Open File 2743) containing many different types of geoscicnce data from the project area which could be viewed using public domain visualization software. In add111on, numerous digitally-produced open file maps and image products have been released since the start of the project i~ 199 l. An archival digital release containing the content of the project database will be prepared for release on CD-ROM in l 997-98.
T hroughout the life of the Shield Margin Project . . expertise in digital methodology was developed both wnhm the provincial surveys and the GSC. Tools and concepts developed during this and other NATMAP projects arc portable and arc being routinely applied to other geological mapping and interpretation projects at the GSC and elsewhere.
Viljoen, D., McMartin, /. , Leclair, A.D., Haid[, F., Bezys, R.K., and McGregor. C. K. ( /997): A 3 -D view of The Pas moraine <irea: Digital elevation modelling of Precambrian, Paleowic and Quaternary surfi,ces; GACIMAC Annual Meeting, Mt1y /997: Ottawa, Alm. Vol .. v22, pA- 154.
The Precambrian, Paleozoic, and Q uaternary geology of The Pas Moraine area immediate ly south of the margin of the Canadian Shield in Manitoba and Saskatchewan has been studied by the different authors in thei r respective fields, as part of the multidisciplinary NAT MAP Shield M_argin Project. The datasets used to construct the elevation models include: I) confidential and non-confidentia l information from drill hole intersections, 2) digital topographic maps at l :50.000 scale (NTS 63K/3, K/4, K/5 and K/6), and 3) new geological maps at l : I 00,000 scale for the buried
Summary of Investigations 1997
Precambrian basement rocks, partly covered Paleo1.0ic sedimentary rocks. and Quaternary sediments. The integration of these datasets resulted in a series of interpretive maps at I :250.000 scale, including digital elevation models for the three geologic-time surfaces under The Pas moraine.
The effects of basement topography on sedimentation reveal interre lationships between the three modelled surfaces. The Pas Moraine is the most prominent glacial ice-contact landform in the Shie ld Margin area. The moraine, which formed as ice was re treating to the east from a Hudson dispersal centre during the Late Wisconsinan, forms a northnortheast-trending belt of thi<.:k till (up to 60 m) west of Clearwater Lake. This major topographic high is characterized by an asymmetrical profile with a steeper slope on the down-ice western side. The moraine is underlain by a depression in the Paleozoic surface. although the ice that formed the moraine probably abulled against a topographic high in the Paleozoic located on the down-ice slope of the ridge. Topography on top of the Precambrian reflects a structural low. In the same area. the Precambrian basement is represented by the Namew Gneiss Complex which is characterized by tight northeast-trending fo lds of orthogneiss and paragneiss.
Saskatcliewan Geolu,:ical S11rv,!y 227
228
Acknowledgments
Saskatchewan Geological Survey project leaders acknowledge the ass istance in the field and office of the following, hired under the Saska1chewan Student Summer Employmenl Program: Daniel Block, Susan Bradley , Colin Card, Chris Coolican, Jeff Coolican, Jason Cosford, Bryan Hartall , Russel Hartlaub, Raza Hasanie, Zoran Jankovic, Alex MacNeil, Joshua McGowan. Christian Miller, Ryan Morelli , Scott Schmidt, Kevin Treptau, and Naomi Wiebe.
The editors a re grateful for assistance given the edit ing and production process by Tammy Albert , Lynn Kelley, Murray Rogers, Laura Smith, and Ho rst Stolz. This report was prepared w ith Word 6.0 for Windows on a Hewlett-Packard LaserJe t 5Si M X printer.
The primary fie ld maps, in the associated but separate ly released map package, were produced using AutoCAD and Fie ldLog software. Bill Slimmon was primarily responsihle for implementing the assembly of the digi ta l maps. Fred Blondeau, Ken Jones, Ken Nolte. and Phil Weir were variously involved in the production o f these maps, and are acknowledged individually where the ir contribution was significant.
Summary of /nvestif.:ations 1997
Northern Geological Survey
T.1.1. Sibbald Director
Resident Geologists
Information/ Education
Field Mapping
and Compilation
Data Processing
Industrial Minerals
Saskatchewan Energy and Mines
EXPLORATION AND GEOLOGICAL SERVICES DIVISION
GeorRe Patterson. ____ ~ Executive Director
Petroleum Geology
D.F. Paterson Director
Regional Geology
Core Warehouse
Well and Geophysical
Records
Support Services
Mines
P.l. Reeves Director
Mines/ Statistics
Mining Lands
Mineral Assessment
The Saskatchewan Geological Survey comprises the geoscience activities of the Northern Geological Survey and Petroleum Geology.
Suskurc/1ewari Geological Survey 229
