Bedrock Geology Compilation Map Series: Grand Rapids NTS

Home , Cedar Lake (Manitoba), The Pas

Manitoba Industry, Trade and Mines Geological Survey MARGINAL NOTES B.G.C.M. Series Grand Rapids, NTS 63G, 1:250 000 The Grand Rapids map sheet (NTS 63G) is underlain by Paleozoic carbonate formations, with the QUATERNARY exception of minor Precambrian bedrock exposures in the northeast corner. The Paleozoic strata Pervasive glacial erosion carved the Grand Rapids area into an outcrop-dominated landscape. Sediment O O represent a portion of the northeastern flank of the Williston Basin and dip gently to the southwest. Recent 100 0 O 98 0

4 000 ’ 0 ’ 0 5 000 cover is restricted to the south along The Pas Moraine and, most likely, to the area north of Lake 50 30 99 0 30 50 glaciation has modified the exposed Paleozoic bedrock. The rocks outcrop in a region known as the O O Interlake, and the Grand Rapids area is where many of Manitoba's caves and karst features are located. Winnipeg, where peatlands dominate. No information is available within the area regarding preLate 54 0 54 0 LEGEND ISOPACH MAPS STRUCTURE CONTOUR MAPS SML Wisconsinan glaciation, although multiple glacial striations and discontinuous older sediments may be SA N The map sheet is blanketed by up to 60 m of glacial till, lake sediments and glacial outwash deposits (see SA present. SA 'Surficial Geology' and 'Overburden Thickness' inset maps). The north basin of Lake Winnipeg occupies N Little Playgreen WESTERN CANADA SEDIMENTARY BASIN McMartin (2000) documented two late Wisconsinan glacial advances in the Flin Flon area, first towards SML Lake a significant portion of the sheet. Stratigraphic coreholes, mineral-exploration drillholes, Water SFB SML SEA SFB G Williston Basin Resources Branch testholes and Manitoba Hydro testholes provide data sufficient to estimate the the south-southeast (315°) and then towards the southwest (045°). The interlobate position between Talbot SML OS SFB Interlake Group Bedrock Topography Kiskittogisu R. 100 O O 100 O O regional structure of the sedimentary strata. Using these data, formation contacts were extrapolated from these ice lobes fluctuated greatly from east to west, and the first of these advances extended to an SA Paleozoic 98 98 54 O 54 O 54 O 54 O known well locations to their intersection with the buried bedrock surface (see 'Bedrock Topography'inset unknown position to the east, with little or no evidence of the advance in the Grand Rapids area. The Lake SA SML Mesozoic 260 280 second advance terminated at The Pas Moraine and deposited the uppermost till, the calcareous silt-rich SA 20 270 map). SA ORR 270 220 220 SML Lower Cretaceous 10 200 Clearwater till in this area (Nielsen and Groom, 1987). The till surface is commonly streamlined SA SFB N 280 270 Large expanses of Paleozoic bedrock are exposed, or partially covered, in the Grand Rapids Uplands 30 260 SML OS 270 due to thin or scattered surficial deposits. Frequent forest fires that have swept through this area have (McMartin, 2000). McMartin (2000) suggested that the Clearwater till may be partly derived from the Ch. Swan River Formation (0- 25m): sandstone to SEA 270 Hudson Bay Lowlands, with a greater amount of locally derived constituents in areas of high rock A shale; kaolinitic; minor lignite; presently known 30 270 280 S William River 30 280 resulted in excellent bedrock exposures. Bedrock exposures also occur as shoreline outcrops along the SML Sepastak 40 10 SEA A PLAYGREEN mainly as outliers within channel and/or karst fill 270260 210 plateaus of Paleozoic age. S McLeod Island 270 many lakes in the area. SA Little Ch. 30 in the Paleozoic outcrop belt 290 250 The Pas Moraine is the most prominent glacial feature in the area. It extends more than 300 km from SML N 40 230 210 Sub-Phanerozoic mineral-exploration drilling for Ni-Cu mineralization along the Superior Boundary Zone SA L a k e 240 L a k e 210 Clearwater Lake, in the north, to Long Point on Lake Winnipeg, in the east. The moraine is a thick wedge SEA SA 50 260 270 (SBZ) in NTS 63G has provided abundant Phanerozoic drill core for stratigraphic evaluation. Core WILLIAM SA OSM Interlake Group 40 280 290 of Clearwater till (McMartin, 2000), up to 20 km wide, that rises as much as 60 m above the surrounding Sepastak 30 logging of these drillholes revealed the existence of numerous outliers of Cretaceous age and unknown SEA W i n n i p e g W i n n i p e g 20 230 220 terrain. The proximal, northeastward-facing slope of the moraine is a gentle ramp (~3 m/km) with SA Silurian 50 30 270 extent. Many shoreline exposures are now flooded in the Cedar Lake area due to the Grand Rapids OS G 260 streamlined features, perpendicular to the moraine trend, which curve to merge with the lobe-shaped SOUTH MOOSE Flett Hydro Dam. SEA Island N Cedar Lake Formation: dolomite, yellow buff, 280 crest, whereas the distal slope is relatively steep (>20 m/km; Matile and Keller, 2002). SEA CL finely crystalline, thin bedded, stromatolitic, 260 210 The Phanerozoic rock sequence overlies the Precambrian and the SBZ. The SBZ is the juncture of the SA Russell S 50 280 SEA 40 270 Lake SA fragmental, micritic, biohermal, biostromal, 30 Superior and Churchill Precambrian cratonic blocks, and is the site of the Thompson Nickel Belt (TNB). The process that led to the formation of The Pas Moraine may have been similar to the model proposed SA Baker reefoid for ice streams, past and present, in Antarctica. Seismic studies on the Antarctic ice stream B showthat SA Langlois 260 270 220 SML Lake Islands East Arm Formation (5- 8m): dolomite, light to 270 the glacier is riding on a 6 m layer of saturated glacial debris (Alley et al., 1987). It was concluded that Trout SEA 210 BEDROCK TOPOGRAPHY Island LAKE LAKE G dark grey, finely crystalline, stromatolitic, SEA 270 most of this deformation till is derived from an up-ice source and not locally. The deformation till is LAKE 260 Bedrock topography in the Grand Rapids map area (see 'Bedrock Topography' inset map) exhibits SML fragmental, oolitic, fossiliferous; containing 40 continuously being carried toward the ice margin and, if the ice-marginal position was maintained in the SCL SFB Limestone Bay SEA SEA argillaceous/arenaceous marker beds 50 260 considerable irregularity. The main upland area consists of dolomite pavement and is bounded to the east vicinity of The Pas Moraine for some time, deformation till would accumulate at the ice margin and SCL 60 by the north-trending Silurian escarpment. The escarpment trends parallel to the east side of Provincial SA SCL eventually avalanche down the distal slope (Fig. 1). This process would have generated a stratigraphic SA Atikameg Formation (3- 7m): dolomite, buff 210 Highway 6 (see the map and cross-sectionA-A' for the location of the escarpment). SA 50 210 record similar to that of a delta, but composed of unsorted debris: what could be referred to as a till delta. OSM orange, massive, vuggy; may contain fossils 40 SEA SFB Using seismic reflection data obtained in the Lake Winnipeg study, Todd et al. (1998) identified the Lower Streak 60 Lake 40 250 Paleozoic section (Winnipeg and Red River formations) as a prominent, buried escarpment, up to 40 m Lake OS G 30 260 SCL 20 high, within Lake Winnipeg. This escarpment represents the Precambrian-Paleozoic boundary (G. SCL SCL SA Moose Lake Formation (0- 10m): dolomite, 210 SCL Davidson SML 250 220 200 SA SFB stromatolitic, micritic 53O 53O 53O 53O Matile, pers. comm., 2002; see cross-section B-B'). O O O 210 O SA 100 98 100 98 The 'Bedrock Topography' inset map shows an irregular surface characterized by erosional lows more SEA SML Limestone than 50 m in depth. These lows may be the result of karst topography (i.e., sinkholes), channel erosion or Fisher Branch Formation (0- 15m): dolomite, Lake SFB structural faulting. Some of these deeply incised topographic lows in the Paleozoic bedrock have been Little fossiliferous SA infilled by Cretaceous outliers. These outliers occur throughout the area of the map sheet; eighteen are Two Mile Stonewall Formation Overburden Thickness Channel

known to exist. At one time, the area may have been covered by Mesozoic sediments that were 0 0 O O 45 ’ SEA 45 ’ Ordovician and Lower Silurian 100 98 O 100 98 O subsequently eroded. Stonewall Formation (0- 20m): dolomite, yellow 54 O 54 O 54 O 54 O 0 0 5 Creek B’ SA SA grey, finely crystalline, fragmental, sparsely The 'Bedrock Topography' inset map reflects regional trends in the rock surface and does not necessarily OS 20 18 0 10 20 20 account for local fluctuations. In areas with Paleozoic bedrock, local fluctuations commonly occur as fossiliferous, interrupted by argillaceous zones 0 0 0 5 karst depressions, resulting in anomalous depth to bedrock values. Alternatively, in areas underlain by SCL SEA and marker beds (T- zone demarcates the 20 5 Precambrian bedrock, east and north of Lake Winnipeg, local relief on the bedrock surface can be as SA SEA Ordovician/Silurian boundary zone); argillaceous 22 5 10 dolomite at the base (Williams Member) 0 much as 20 m and the depressions are commonly filled with Quaternary sediments (see cross-section B- SML 18

59 22 Griffin 5 10

50 B'). 000 Lake Ordovician SEA 1 0

000 0 50 Cypress 22 L a k e L a k e Bracken Ck. Stony Mountain Formation (0- 40m): dolomite, 0 PRECAMBRIAN UNCONFORMITY 59 SCL 24 20 OSM yellow brown, nodular, colour- mottled in part, 22 5 22 W i n n i p e g 0 W i n n i p e g 26 5 The Precambrian strata are unconformably overlain by basal Paleozoic sandstone of the Middle massive 24 2220 Ordovician Winnipeg Formation. The Precambrian surface is interpreted to have been peneplaned, but 0 5 Red River Formation (0- 70m): dolomite, in part 20 0 numerous irregularities are present in this area (see 'Precambrian Topography' inset map; Bezys and Lakes Oskatukaw River ORR fossiliferous, mottled; upper part is Fort Garry McCabe, 1996). Lake 0 Eagle Member 22 22 5 5 In the William Lake area, mineral-exploration drilling by Falconbridge Ltd. encountered topographic highs Bracken ORR Island Hungry Winnipeg Formation (0- 12m): sandstone, 24 5 over the Precambrian surface as great as 35 m, between holes less than 1 km apart. Their drilling Figure 1: Seismic profile from the bed of the Ross Sea, Antarctica, showing stratigraphic relationships 22 Lake OW quartzose; rounded, frosted sand grains; 0 targeted the Precambrian along the SBZ, and such extreme variations on top of the Precambrian suggest attributed to the formation of a till delta (WestAntarctic Ice Sheet Working Group, 1994). Kaneeneeki L. interbedded green, waxy shale with sand and silt the existence of faulting or tectonic reactivation of faults affecting the Paleozoic strata (Bezys, 1996a). This process may also explain the formation of the curvilinear streamlined landforms up ice from The Pas E S C A R P M E N T interbeds 5 22 5 Near Bracken Lake (Twp. 54, Rge. 16, W 1st Mer.), Falconbridge Ltd. drillhole BL-94-77 indicated a Moraine and to the south. In a proglacial lake environment (see description of Lake Agassiz, below), SCL Kawawakehawak Precambrian structural low of approximately 145 m below the normal structural elevations. This low where the majority of the ablation is a result of iceberg calving, the subglacial morphology of the OSM consisted of 85 m of possible Cambrian Deadwood Formation, which overlies weathered Precambrian deformation till may have been left undisturbed. SML SFB MOLSON LAKE DOMAIN granitic fault breccia. Since the Deadwood Formation is present only in southwestern Manitoba, the SA 5 As these glaciers retreated to the north and northeast, Lake Agassiz inundated the area. Clay and silt Proterozoic 5 24 Bracken Lake low may be a graben structure that sheltered the strata from erosion. attributed to LakeAgassiz were deposited in deep water and are found in the low areas, including the area SML Kinapik 22 10 Lake 50 5 10 20 20 30 The Norris Lake anomaly is a Precambrian structural high located in 19-51-15-W1, 8 km south of Norris underlying the extensive fen north of Lake Winnipeg. Littoral sand and gravel, deposited in shallow water Diabase and gabbro dikes, massive (Molson 53O 53O 53O 30 10 53O Lake. This 61 m high was encountered in drillhole MXD-72-1 by AmaxExplorationLtd. Two metres of along the LakeAgassiz shoreline, occur along the Silurian rock escarpment west of Lake Winnipeg. swarm) 100 O 98O 100 O 98O extensive brecciation and carbonate-quartz-pyrite veinlets were intersected between the overlying McMartin (2000) documented six well-defined Lake Agassiz strandlines (from oldest to youngest: Kawakwunwit Clearwater SEA Lake Paleozoic sediments and the Precambrian (B. Bannatyne, internal government document, 1981). Stonewall, The Pas, Gimli, Grand Rapids, Drunken Point and Ponton), which were formed in the period Lake Sturgeon The Denby structure is situated in 46-16-W1, south of the village of Easterville. The Precambrian surface from about 8300 to 7800 years before present (BP). During that period, this area would have Kanepetakayo 6 SEA Archean Stony Mountain Formation Depth to Precambrian is 107 m above the normal structural elevations and coincides with the outline of a strong aeromagnetic progressively emerged from LakeAgassiz, first appearing as islands along The Pas Moraine, and then as Menauhswun L. A Lakes Granite, leucocratic, biotite bearing, massive to 100 O O 100 O O high. The Cominco Denby number 2 drillhole, drilled in 1971, intersected 91.4 m of red, blue and grey clay rock plateaus (McMartin, 2000). During this time, Lake Agassiz drained into the Atlantic Ocean, first Kaministikoskatukak SA G 98 98 Lake porphyritic 54 O 54 O 54 O 54 O containing a thick layer of uniformly sorted, fine-grained sand with abundant marcasite nodules. Between through Lake Superior and then through Lake Ojibway-Barlow and the Ottawa River, before finally Kawisapiskeetak SML Gill 120 Lake 90 91.4 and 114.0 m, a sequence of sand-clay-limestone was encountered. Paleozoic dolomite was present disappearing about 7700 years BP (Thorleifson, 1996). 28 110 ? between 114.0 and 130.1 m, and Precambrian serpentine was intersected at 130.1 m. Winnipeg SFB Diabase dikes, massive to foliated 120 Formation was absent in this hole. These data are interpreted to indicate that 80 to 105 m of local, post- 28 Creek 28 26

30 ’ 0 30 ’ 0 Ordovician, probably pre-Mesozoic structural uplift occurred (McCabe, 1978). 120 120 Mostosis SA LAKE Intermediate layered gneiss with granitoid Lake 30 Thirteen kilometres northwest of the Denby structure is Cominco's drillhole RP-96-21, which intersected Cedar Norris 30 28 Lake Lake N phases, derived in part from quartzofeldspathic 28 30 150 Cretaceous accretionary lapilli in a pre-Mesozoic channel (Bezys et al., 1996). Micropaleolontology data 160 SURFICIAL GEOLOGY SEA sediment 30 L a k e 80 L a k e from the sedimentary rocks indicate they are of Mesozoic age (A.R. Sweet, internal government report, 4- A’ 160 O 160 100 ARS-1997). The lapilli occur at the base of a channel cut into the Paleozoic and infilled with strata of 100 O 30 150 98 SEA W i n n i p e g W i n n i p e g Mesozoic age. The Mesozoic infill consists of light brown and tan to white (some red), very fine grained, O O Perch 28 54 54 170 140 120 Lake SCL SCL 30 32 consolidated and unconsolidated sand, silt and clay. Interbedded with these sediment types are minor R2 2 R1 2 150 amounts of black shale and sand. The interval 133.1 to 136.6 m contains a light brownish tan lapilli tuff Kakinokumak 160 140 5 32 20 with small accretionary lapilli, 0.1 to 2 cm in size. Thin sections indicate that the lapilli beds are composed Lake 2 SML 30 120 of fresh, intermediate volcanic and pyroclastic rocks. Accretionary lapilli usually fall within a few 1 R1 26 R2 OS 32 kilometres of the eruptive vent and are rare at distances greater than 20 km (Bezys et al., 1996). There are Perch Ck. Kameesak Buffalo 160 ? Lake Lake no known eruptive volcanoes in the vicinity of Denbeigh PointEasterville. The Paleozoic strata adjacent to Fiddler Ck. 30 5 180 this erosional channel do not appear to be otherwise disturbed. 1 Buffalo Ck. 32 The Ochre Lake structure is an area of disturbance that has affected the Silurian bedrock. A disturbed 4 3 North 190 zone, approximately 100 m wide, contains sideritized carbonate breccia, abundant clay (ochre-like) and R2 1 Clear Bay Kawuchuskwaskasik 1 Lake siliceous boulders. The EastArm Formation dolomite beds are extremely jointed and discoloured (Bezys, Robertson Island 32 200 5 (Cedar Lake) Kawakikamak Kaministikwak Lake Lake SFB 130 1996b). All of the above anomalous structures occur within the Paleozoic along strike with the SBZ. Lake 150 Lake Muskwa 30 210 3 140 ? Structural cross-sectionA-A' indicates a relatively flat topped Precambrian surface, with a slight flexure at 5 34 220 150 Ck. 32 30 the extreme western end of the section.Again, this part of the section lies on top of the SBZ. Datum for this 230 160 Lake SEA SFB 53O 26 36 53O 53O 53O cross-section is hung on the 'T-zone' marker bed. Ochre 6 SML 100 O 98O 100 O 98O 5 Lake South Kawuchuskwaskasik Lake SCL PALEOZOIC R2 5 5 1 Winnipeg Kamuskoseyakamak McKay REGIONAL STRUCTURAL GEOLOGY Lake Lake Woody Regional strike of the sedimentary strata is approximately north-south, with the exception of a slight Pootachikun Red River Formation Precambrian Topography 5 SCL Bay Kakinokumasik Lake SA Horse O O O O northwesterly strike adjacent to the north edge of the map sheet. The regional structural dip increases Lake Woody WINNIPEG 100 98 100 98 Point 54 O 54 O 54 O 54 O gradually and uniformly from about 1.0 m/km at the western shore of Lake Winnipeg to 1.5 m/km in the Creeks Island R2 SCL S I L U R I A N Toboggan 40 160 western part of the map sheet. Despite the regional structural dip to the west, isopachs of the Winnipeg to L. 160 1 CROSS OSM 140 Stonewall formations generally trend east (see Winnipeg, Red River, Stony Mountain and Stonewall 45 45 Kaseekwaywinakunok L. 45 isopach inset maps), and thicken to the south. This indicates a major change in tectonic framework 1 Pony subsequent to early Paleozoic time. The current north-striking structural trend probably developed during Island 160 Foot the late Paleozoic to early Mesozoic, due to uplift with associated erosion and eventual exposure of SCL Print OS 50 140 Lake 50 Precambrian bedrock in eastern Manitoba (the Severn Arch). See Bezys and McCabe (1996) for further 120 R2 SEA Ck. 120 details. 5 70 L a k e L a k e Kakakenowuchewun Point 50 110 Lake 100 1 5 R2 55 55 W i n n i p e g W i n n i p e g

3 0 0 CAMBRIAN 1 15 ’ SA 15 ’ 140 O O B 53 53 Eating 120 160 Deadwood Formation O O 98 55 120 100 60 The Deadwood Formation occurs in this map sheet as outliers in two localities. In both localities, it was 140 SCL SA 45 intersected in a drillhole below a sequence of Silurian and Ordovician rocks. The Deadwood Formation in R1 Precambrian bedrock 2 Lake Agassiz clay and silt SML 140 SYMBOLS 140 120 these holes consists of a complexsequence of dark grey, micaceous, argillaceous siltstone to sandstone. Mechiso In places, the unit is crossbedded, with intervals of disrupted laminations. At Bracken Lake, the 3 Lake Agassiz beach sediment Lake 60 120 R2 Paleozoic rock Geological boundary (defined or approximate, 100 Falconbridge Ltd. drillhole BL-94-77 encountered 85 m of Deadwood Formation and the Precambrian is 110 4 Lake Winnipeg beach sediment interpreted) 80 structurally low, at 145 m. The other occurrence is at the Denby structure and has not been clearly 100 identified as Deadwood Formation. The presence of this stratum so far removed from the actual 1 Calcareous till 5 Organic deposits Bay Paleozoic outcrop 70 Portage Deadwood Formation subcrop indicates that the formation was regionally present in this area but Lamb BAY Bay 60 80 Quarry (crushed stone, dolomite) 90 subsequently eroded. It is suggested that the intersected Deadwood Formation represents remnants Grand Rapids 50 60 preserved in a graben-like structure. Napanee 65 Stratigraphic core hole 100 Bay Fire 40 65 60 120 ORDOVICIAN Mineral exploration drillhole O O O 140 O SFB 53 70 53 53 53 Winnipeg Formation 100 O 98O 100 O 98O Domain boundary Collins Harbour Bay The Winnipeg Formation in this map sheet consists of interbedded sandstone, siltstone and minor shale. C E D A R Island L A K E Stable L. Sa OSM skatc Regionally, the formation thins and becomes increasingly sandy to the north, in comparison to southern ECONOMIC GEOLOGY hewan River map sheets (McCabe, 1978). The sand is poorly consolidated, medium grained, mature, well rounded Caves and/or karst features 200 204060 This area has received considerable attention from the mineral-exploration community, since it underlies Winnipeg Formation and quartzose; the shale is commonly light olive-grey and kaolinitic, with variable sand and silt content. Easterville the inferred southern extension of the Thompson Nickel Belt (TNB). Exploration was initiated in the late O O 100 98 KILOMETRES The maximum thickness of the Winnipeg Formation in NTS 63G is 27 m (averaging 9 m; see Winnipeg 1960s with a follow-up on the results of a federal-provincial aeromagnetic survey. Freeport Canadian 54 O 54 O Area of little or no Phanerozoic outcrop 12 410 Formation isopach inset map). Exploration Ltd. undertook geophysical surveys and diamond drilling. This work was followed up byAmax 10 10 8 Muskeg 8 10 CONTOURS IN METRES Red River Formation Exploration Ltd. and continued with a joint venture of Amax and Granges Exploration Ltd. from 1969 until Lake

Winnipeg Formation sandstone and shale are overlain conformably and transitionally by mottled 1987. In 1971, Cominco Ltd. initiated exploration of the Lake Winnipegosis komatiite belt, including deep- Horseshoe Area of little or no Precambrian outcrop 10 12 Onuhupeewin Ck. SFB Island 10 Ck. SML 8 12 Superior Phanerozoic- dolomitic limestone of the Red River Formation, 11 to 97 m in thickness (averaging 51 m; see Red River penetrating geophysical surveys (UTEM) and diamond drilling. This program lasted until 1999. SCL OS 10 4 12 Boundary Zone Precambrian Formation isopach inset map). The transition zone consists of a thin sequence of interbedded limestone Falconbridge Ltd., however, concentrated on the southern extension of the Thompson Nickel belt in a Shallow Beaver Dam 10 boundary currently active exploration campaign that began in 1988. Onuhupeewin Bay 4 8 and shale, termed the 'Hecla Beds' (Porter and Fuller, 1959). The Red River Formation consists of two Lake Lake SA 10 8 Cross Bay 6 principal subunits, the lower Red River and upper Red River, which can be distinguished in this map The Winnipegosis komatiite belt (Hulbert et al., 1994) occurs to the east of theTNB. It consists of 10 L a k e 327 SEA ANOMALOUS FEATURES: 8 sheet. The lower Red River is approximately equivalent to the Yeoman Formation in Saskatchewan. komatiitic flows and ultramafic intrusive bodies interlayered with massive and pillowed tholeiitic basalt, ...... Little Moose 1 Bracken Lake Deadwood Formation 3 6 W i n n i p e g Lower Red River strata consist of light grey to yellowish and brownish buff, prominently mottled, sulphide-bearing argillite, calcareous mudstone and dolomite. Cominco focused its attention on the 2 lake 4 SCL Morrison 2...... Cretaceous accretionary lapilli 12 fossiliferous, commonly cherty dolomite. The unit cannot be subdivided into its constituent members potential of this rock assemblage for komatiite-hosted Ni-Cu deposits. 10 4 OSM 3...... Deadwood Formation (reported) 8 (Dog Head, Cat Head and Selkirk, in ascending stratigraphic sequence) in this map sheet, since they Mineral exploration in this map area is challenging, since it is largely covered by Phanerozoic Lake Hole in 8 6 Saskachaywiak the Wall 12 Ck...... 2 occur in southern Manitoba only. The upper part of this unit, equivalent to the Selkirk 'Tyndall Stone', is sedimentary rocks that, in places, are 235m thick. Geophysical surveys must not only overcome this LONG POINT 4 Denby structure 16 4 ORR 6 extensively quarried at Garson in southern Manitoba. 18 depth but also compensate for geophysical anomalies caused by saline karst-borne water. 6 5...... Norris Lake anomaly The upper Red River strata, consisting of dolomite and argillaceous cherty dolomite, is designated the O O 10 Crushed stone (dolomite) from the Silurian bedrock is used intermittently for local highway construction ...... 53 0 53 0 6 Ochre Lake structure 6 Fort Garry Member. These beds are approximately equivalent to the Herald Formation in Saskatchewan. 8 projects.Abandoned dolomite quarries around the Grand Rapids Hydro Dam provided the large amounts 4 4 O O 4 000 5 000 4 Thin argillaceous breccia zones are believed to represent zones where evaporites have been dissolved 0 50 O 50 0

0 0 8 of crushed stone required for its construction. 100 30 ’ 30 ’ 98 86 99 0 10 by subsurface dissolution. 10

Stony Mountain Formation PRECAMBRIAN 12 The Red River Formation is overlain sharply, and possibly with slight disconformity, by shaly beds of the With the exception of the small area of Precambrian-dominated terrain in the extreme northeastern part Universal Transverse Mercator Projection Printed 2002 Stony Mountain Formation. In NTS 63G,the Stony Mountain Formation ranges in thickness from 11 to 40 of the map area, the entire Precambrian surface in NTS 63G is overlain by Paleozoic and/or Quaternary Zone 14 North American Datum 1983 14 4 True 6 North m (averaging 29 m; see Stony Mountain Formation isopach inset map). In Manitoba, this formation is sediments. The geological map of the sub-Phanerozoic Precambrian basement is based on petrographic 8 14 subdivided into three members, in ascending stratigraphic order, the Gunn, Penitentiary and Gunton 10 12 data from coreholes drilled by the government and mining companies (largely in the western half of the Scale 1:250 000 53O 53O members. In NTS 63G,this subdivision in not present and the entire unit is Gunton-like, specifically a buff, area). In addition, this compilation used interpretations from the aeromagnetic map, as well as 100 O 98O finely crystalline, sparsely fossiliferous, nodular-bedded dolomite. In southern Manitoba, the Gunton information from exposed Precambrian outcrops in the adjacent NTS areas 63J (Manitoba Energy and Kilometres5 0 5 10 15 20 25 Kilometres Member is extensively used for crushed stone, extracted from quarries in the Stonewallarea. O Mines, 1993) and 63H (Manitoba Energy and Mines, 1999). Distinctive magnetic patterns, as seen in the 6 34’ E Magnetic Anomaly Map (see inset map), have been used to subdivide the Precambrian basement into 200 204060 ORDOVICIAN/LOWER SILURIAN Archean Superior Province, Superior Boundary Zone and Proterozoic Trans-Hudson Orogen (see 'Sub- Stonewall Formation Phanerozoic Precambrian Geology' inset map). KILOMETRES The Williams Member, herein placed as the basal unit of the Stonewall Formation, represents the oldest Superior Province in a series of so-called 'paratime-stratigraphic' markers: thin sand and/or argillaceous beds that can be ISOPACHS IN METRES Magnetic North traced for many hundreds of kilometres, throughout most of the Williston Basin area. These marker beds The Superior Province has been subdivided into theBerens River Domain and the Molson Lake provide the primary means for stratigraphic subdivision of Upper Ordovician and Silurian strata, and Domain using potential field data (Pilkington and Thomas, 2000). Further subdivision into various lithological units has been accomplished by extending units from adjacent map sheets based on Approximate mean declination probably represent deposits related to brief periods of shoaling or even slight uplift and erosion (i.e., Outcrop/subcrop nonsequences; Porter and Fuller, 1959). comparable aeromagnetic signatures and rare diamond-drill hole (DDH) information. STRATIGRAPHIC CROSS SECTION A - A’ Erosional edge (2002) for centre of map area Decreasing 7.8’ annually The lower Stonewall beds, above the Williams Member, consist of approximately 7 m of pale yellowish Broad, moderate magnetic highs in the Berens River Domain are interpreted to be caused by grey to yellowish brown, faintly mottled, medium- to thin-bedded, finely crystalline dolomite with sparse, granodioritic to tonalitic batholiths (unitGd ). This has been confirmed by one drillhole. The plutons generate a series of linear magnetic anomalies that trend southwest. A drillhole confirmed that these poorly preserved fossils. These beds are separated by a sandy argillaceous marker bed, the 'T-zone', Superior Phanerozoic- from the upper Stonewall Formation (Porter and Fuller, 1959). The upper Stonewall beds consist of anomalies occur over mafic dikes of the Molson Dike swarm, as described by Scoates and Macek (1978). Broad areas of low magnetic values are attributed to intermediate gneiss with granitoid phases (unitNs ). Boundary Zone Precambrian approximately 6 m of light brown to grey, laminated to thin-bedded, sparsely fossiliferous microcrystalline boundary dolomite. The formation is capped by a thin, argillaceous marker bed, called the 'Upper Stonewall Within this gneiss, areas of slightly higher magnetic signatures are interpreted to occur over SELECTED BIBLIOGRAPHY Member'. In this map area, the Stonewall Formation can reach a thickness of 35 m (averaging 20 m; see metavolcanic-metasedimentary rocks (unitV ), with small, concentric magnetic highs characteristically Stonewall Formation isopach inset map). The Ordovician-Silurian boundary occurs within the upper part related to ultramafic rocks (unitUM ). Areas of 'mottled' low and high magnetic anomalies are interpreted to be caused by granitoid gneiss, probably containing supracrustal rocks (unitN ). The moderate to weak Alley, R.B., Blankenship, D.D., Rooney, S.T.and Bentley, C.R. Bezys, R.K., Matile, G.L.D.and Keller, G.R. McRitchie, W.D. Synoptic geology by R. Bezys, with contributions by C.R. McGregor, of the Stonewallsequence, associated with the T-zone (Bezys, 1991; Haidl, 1991). 1987: Till beneath ice stream B 4: a coupled ice-till flow model; Journal of 2001: Investigations of Precambrian monadnocks (NTS 62I/1 and 62I/8); in 1996: Groundwater geochemistry and structural investigations of Paleozoic G.L.D. Matile, J.D. Bamburak, H.D. Groom and G.R. Keller linear magnetic anomalies that trend southwesterly indicate that the supracrustal rocks may, in turn, Geophysical Research, v. 92, no. B9, p. 89318940. Report of Activities 2001, Manitoba Industry, Trade and Mines, Manitoba carbonates in Manitoba's Interlake Region; in Report of Activities 1996, SILURIAN contain mafic intrusions. Baillie,A.D. Geological Survey, p. 133-137. Manitoba Energy and Mines, Geological Services, p. 143-152. Compilation by R. Bezys and D. Lindal The Molson Lake Domain is dominated by a large, high-intensity aeromagnetic signature interpreted to 1951: Silurian geology of the Interlake area, Manitoba; Manitoba Department of Bezys, R.K. and McCabe, H.R. McRitchie, W.D. and Kaszycki, C.A. Interlake Group Digital CAD drafting by T. Franceschet be caused by enderbite to enderbitic gneiss (unitEn ). The magnetic anomaly is very similar to that of the Mines and Natural Resources, Mines Branch, Publication 50-1, 82 p. 1996: Lower to Middle Paleozoic stratigraphy of southwestern Manitoba; 1997: Bedrock fracture orientations, Manitoba Interlake Region; Manitoba The Interlake Group in this map area comprises a 0 to 76 m (averaging 30 m) sequence of dolomite, Pikwitonei Granulite Domain in NTS area 63P (Manitoba Energy and Mines, 1995); this area may Bamburak, J.D. and Bezys, R.K. Geological Association of Canada Mineralogical Association of Canada, Energy and Mines, Geological Services, Preliminary Map 1997P-3; scale Database geologist G. Conley ranging from variably fossiliferous and stromatolitic to predominantly finely crystalline and dense to 1995: Capital Region resource evaluation project (NTS 62I/3); in Report of Joint Annual Meeting, Winnipeg, Manitoba, May 2729, 1996, Field Trip 1:750 000. therefore contain a southwestward extension of that domain. The broad, moderate magnetic signature Activities 1995, Manitoba Energy and Mines, Geological Services, p. 151- Guidebook B4, 92 p. McRitchie, W.D. and Monson, K.M. (Ed.) GIS Cartography by L. Chackowsky sublithographic. The Silurian occurs as exposed bedrock over large expanses of this map sheet and is surrounding the enderbite is attributed to rocks ranging in composition from granodiorite to tonalite (unit severely eroded in places. Minor lithological variations, along with the occurrence of several thin, sandy, 154. Brindle, J.E. 2000: Caves and karst in Manitoba's Interlake Region (second edition, 2000); Gd). Linear aeromagnetic signatures within the granitoid rocks also suggest the presence of a few 1996: Capital Region study: update 1996 (NTS 62H and 62I); in Report of 1960: The faunas of the lower Paleozoic carbonate rocks in the subsurface of SpeleologicalSociety of Manitoba; 181 p. Suggested reference: argillaceous marker beds, are used to subdivide the Interlake Group into the following members (in Molson dikes with the same northeast trend as in the Berens River Domain. Activities 1996, Manitoba Energy and Mines, Geological Services, p. 103- Saskatchewan; Saskatchewan Department of Mineral Resources, Report Michalyna, W., Gardiner, W. and Podolsky, G. Manitoba Industry, Trade and Mines ascending stratigraphic order): Fisher Branch, Moose Lake,Atikameg, EastArm and Cedar Lake. 107. 52. 1975: Soils of the Winnipeg region study area; Canada-Manitoba Soil Survey, Superior Boundary Zone Bannatyne, B.B. Derry Michener Booth and Wahl and Ontario Geological Survey 241 p. 2002: Grand Rapids, NTS 63G; Manitoba Industry, Trade and Mines, MESOZOIC OUTLIERS Various lithological units belonging to the TNB have been observed in diamond-drill core, and contacts 1975: High-calcium limestone deposits of Manitoba; Manitoba Mines, 1989a: Limestone industries of Ontario, Volume I geology, properties and Mitchell, P. Manitoba Geological Survey, Bedrock Geology Compilation Map Resources and Environmental Management, Mineral Resource Division, ecnomics; Ontario Ministry of Natural Resources, Land Management 1983: Sand and gravel resources of the Selkirk and District Planning Area; Series, NTS 63G, scale 1:250 000. Outliers of Mesozoic age are abundant in NTS 63G as channel infill within the Paleozoic bedrock. There have been interpreted from aeromagnetic signatures. A series of thin, curved, magnetic anomalies in the northeast-trending Superior Boundary Zone (SBZ) indicate the possible presence of the Ospwagan Publication 75-1, 103 p. Branch, 158 p. Manitoba Energy and Mines, Mines Branch, Maps SD1 and SD2. are 18 known occurrences in the map area, all but one having been identified in mineral-exploration 1980: Dolomite resources of southern Manitoba; in Report of Field Activities 1989b: Limestone industries of Ontario, Volume II limestone industries and Nielsen, E. and Groom, H. drillholes; the exception is the outcrop exposure at Ochre Lake. The rocks range from varicoloured shale Group metasedimentary rocks (unit oS ). These clastic and chemical sedimentary units host Ni-Cu-PGE 1980, Manitoba Department of Energy and Mines, Mineral Resources resources of eastern and northern Ontario; Ontario Ministry of Natural 1987: Western Manitoba; in The Quaternary Between Hudson Bay and the GEOLOGICAL DOMAINS Published by: O O

100 0 98 0 and siltstone to sandstone, and may contain lignite fragments, bentonite seams and accretionary lapilli (platinum group element) deposits such as the William Lake deposit. These sedimentary rocks occur in Division, p. 74. Resources, Land Management Branch, 196 p. Rocky Mountains, B.T. Schreiner, L.A. Dredge, E. Nielsen, R.W. Klassen, O O 54 0 54 0 Manitoba Industry, Trade and Mines (as discussed above). Preliminary micropaleolontological work on the sediments indicate a Barremian to the reworked basement gneiss and migmatite of the TNB (unitTNBG ). The TNB granitoid rocks are 1988: Dolomite resources of southern Manitoba; Manitoba Energy and Mines, 1989c: Limestone industries of Ontario, Volume III limestone industries and M.M. Fenton and J.R. Vickers (ed.), International Union for Quaternary Manitoba Geological Survey MiddleAlbian age (Cretaceous;A.R. Sweet, internal government report, 4-ARS-1997). characterized by low and flat aeromagnetic signatures. The eastern boundary of the SBZ is marked by a Minerals Division, Economic Geology Report ER85-1, 39 p. plus 4maps. resources of central and southwestern Ontario; Ontario Ministry of Natural Research, XII International Congress, National Research Council of narrow band of Winnipegosis mafic-ultramafic rocks (unitWV ; Thompson Nickel Belt Geology Working Bannatyne, B.B. and Jones, C.W. Resources, Land Management Branch, 175 p. Canada, Ottawa, Excursion Guidebook C-13, p. 23-33. Group, 2001a, b, c). 1979: Dolomite resources of the southern Interlake area: geology and bedrock Goudge, M.F. Norford, B.S., Haidl, F.M.,Bezys, R.K., Cecile, M.P.,McCabe, H.R. and Paterson, D.F. topography, depth to bedrock; Manitoba Department of Mines, Natural 1944: Limestones of Canada; their occurrence and characteristics: Part V, 1994: Middle Ordovician to Lower Devonian strata of the Western Canada Trans-Hudson Orogen Resources and Environment, Mineral Resources Division, Preliminary western Canada; Bureau of Mines, Canada, Mines and Geology Branch, Sedimentary Basin; in Geological Atlas of the Western Canada Rocks of the Trans-Hudson Orogen occur only in the extreme northwestern part of the map sheet. The Maps 1979DR-5 to -12 (NTS 62I/2, I/3, I/6 and I/7), scale 1:50 000. Report 811, 233 p. Sedimentary Basin, G.D. Mossop and I. Shetson (comp.), Canadian low and flat magnetic signature is attributed to the Burntwood Group metaturbidite and derived migmatite Barker, M.A. Groom, H.D. Society of Petroleum Geologists and Alberta Research Council, Calgary, 1984: Paleokarst features containing Mesozoic sediment in the Western 1999: Updating aggregate maps in R.M. of Ochre River and the capital region; in Alberta, p. 109-127. (unitBW ; Syme et al., 1998) of the Flin Flon Domain (Pilkington and Thomas, 2000). Interlake Region of Manitoba; B.Sc. thesis, University of Manitoba, Report of Activities 1999, Manitoba Industry, Trade and Mines, Geological Norford, B.S., Nowlan, G.S.,Haidl, F.M.and Bezys, R.K. MOLSON LAKE Winnipeg, Manitoba, 37 p. Services, p. 123-124. 1998: The Ordovician-Silurian boundary interval in Saskatchewan and BEDROCK GEOLOGY COMPILATION MAP SERIES Betcher, R.N. Groom, H.D. and Nielsen, E. Manitoba; in Proceedings of the 8th International Williston Basin 1986: Groundwater availability map series, Selkirk area (NTS 62I); Manitoba 1987: Till provenance as it relates to the glacial history of The Pas Flin Flon area, Symposium, Regina, Saskatchewan, October 1998, p. 27-45. DOMAIN Natural Resources, Water Resources Branch, 11 figures at 1:250 000 Manitoba; Geological Association of Canada/Mineralogical Association of Pilkington, M. and Thomas, M.D. scale. Canada, JointAnnual Meeting, 1987, Program withAbstracts, v. 12, p. 50. 2000: Interpreted Precambrian basement maps for Manitoba from potential field Bezys, R.K. Haidl, F.M. data; Geological Survey of Canada, poster display at Manitoba Mining GRAND RAPIDS 1990: Paleozoic geology of the Grand Rapids area (NTS 63G); Manitoba 1991: Note on the Ordovician-Silurian boundary in south eastern and Minerals Convention. Energy and Mines, Geological Services, Preliminary Map 1990m-1, scale Saskatchewan; in Summary of Investigations 1991, Saskatchewan 2001: Magnetic and gravity maps with interpreted Precambrian basement, 1:250 000. Geological Survey, Miscellaneous Report 91-4, p. 213-219. Manitoba; Geological Survey of Canada, Open File 3739, 4map sheets at NTS 63G 1990: Stratigraphic mapping (NTS 63G) and core hole project, 1990; in Report of Hobson, G.D.,Scott, J.S. and van Everdingen, R.O. 1:1 500 000 scale. Activities 1990, Manitoba Energy and Mines, Minerals Division, p. 140- 1964: Geotechnical investigations, Red River Floodway, Winnipeg, Manitoba; Porter, J.W. and Fuller, J.G.C.M. 151. Geological Survey of Canada, Paper 64-18, 43 p. 1959: Lower Paleozoic rocks of northern Williston Basin and adjacent areas; WESTERN CANADA SEDIMENTARY BASIN 1996a: Stratigraphic mapping (NTS 63G) and corehole drilling program 1996; in Hulbert, L., Kyser, K., Carlson, R., Lesher, M. and Joudrie, C. Bulletin of the American Association of Petroleum Geologists, v. 43, no.1, Report of Activities 1996, Manitoba Energy and Mines, Minerals Division, 1994: The Winnipegosis komatiites: a new komatiite belt, central Manitoba; p. 124-189. PRECAMBRIAN GEOLOGY p. 96-102. Geological Survey of Canada, Minerals Colloquium, Ottawa, Ontario, ProAm Exploration Corporation BERENS RIVER INDEX MAP AND MAJOR TECTONIC DIVISIONS PRINCIPAL GEOLOGICAL DOMAINS 1996b: Sub-Paleozoic structure in the Manitoba's northern Interlake along the January 1719, 1994, Program withAbstracts, p. 21. 1997a: ProAm update; Press Release, March 20, 1997. 100O 98O Churchill Superior Boundary Zone: a detailed investigation of the Johnston, W.A. 1997b: ProAm announces funding and begins diamond drill program on its DOMAIN Published 2002 54O 54O Falconbridge William Lake study area; Manitoba Energy and Mines, Open 1946: Glacial Lake Agassiz, with special reference to the mode of deformation of Golden Boy project near Winnipeg, Manitoba; Press Release, October 17, O O O File Report OF94-3, 32 p. the beaches; Geological Survey of Canada, Bulletin7, 20 p. 1997. O O O 100 0 96 0 92 0 BW 100 0 96 0 92 0 Bezys, R.K. and Bamburak, J.D. Jones, C.W. 1999: Golden Boy Project; Information Bulletin, January 1999, 6 p. OS Gn Nunavut 1997: Stratigraphic and industrial minerals corehole drilling program; in Report 1986: The aggregate potential of selected Paleozoic and Precambrian rocks in Render, R.W. A A’ Nunavut TNB G En of Activities 1997, Manitoba Energy and Mines, Minerals Division, p. 123- Manitoba; Manitoba Energy and Mines, Mines Branch, 13 p. 1970: Geohydrology of the metropolitan Winnipeg area as related to NEJANILINI 0 50 100 150 200 250 128. MacLaren, James F.Limited groundwater supply and construction; Canadian Geotechnical Journal, v. 0 50 100 150 200 250 MUDJATIK 64N TNB G Bezys, R.K., Bamburak, J.D. and Conley, G.G. 1980: Mineral aggregate study of the southern Interlake region; Manitoba 7, p. 243-274. 64O 64P 54M KILOMETRES O G KILOMETRES O SEAL RIVER GREAT 59 0 WV 1999a: Capital Region Study: mineral resource potential and overburden Department of Mines and Environmental Management, Mineral Ringrose, D., Large, P.and Duyf, C. 59 0 O WOLLASTON Trans-Hudson Orogen O 59 0 thickness, Selkirk (NTS 62I/2); Manitoba Energy and Mines, Geological Resources Division, Open File Report OF80-2, v. 1 and 2, 51 p. 1977: Quaternary geology of the Winnipeg region; Manitoba Energy and Mines, 59 0 Churchill Churchill Seal River ISLAND Services, Preliminary Map 1999CAP-1, scale 1:50 000. Manitoba Energy and Mines Mines Branch, Map Wpg-14. Seal River Molson Lake Domain 1999b: Capital Region Study: geology and bedrock topography, Selkirk (NTS 1993: Wekusko Lake, NTS 63J, preliminary edition; Manitoba Energy and Scoates, R.F.J.and Macek, J.J. 64K 64J 64I 54L 54K OS 62I/2); Manitoba Energy and Mines, Geological Services, Preliminary Mines, Bedrock Geology Compilation Map Series, scale 1:250 000. 1978: Molson dyke swarm; Manitoba Department of Mines, Resources and H U D S O N O Gd H U D S O N River S Map 1999CAP-2, scale 1:50 000. 1995: Sipiwesk, NTS 63P; Manitoba Energy and Mines, Bedrock Geology Environmental Management, Mineral Resources Division, Geological River C H I P E W Y A N O O 1999c: Capital Region Study: mineral resource potential and overburden Compilation Map Series, scale 1:250 000. Paper 78-1, 53 p. 53 0 53 0 B A Y Gd O O B A Y

100 0 98 0 Ns thickness, Stonewall (NTS 62I/3); Manitoba Energy and Mines, 1997: Selkirk, NTS 62I; Manitoba Energy and Mines, Bedrock Geology Shetty, S. P A L E O Z O I C Geological Services, Preliminary Map 1999CAP-3, scale 1:50 000. Compilation Map Series, scale 1:250 000. 1994: Industrial minerals; Manitoba Energy and Mines, Mines Branch, Internal V 64F 64G 64H 54E 54F SOUTHERN INDIAN O N 1999d: Capital Region Study: geology and bedrock topography, Stonewall (NTS 1999: Norway House, NTS 63H; Manitoba Energy and Mines, Bedrock Geology Government Report, 14p. O

Southern Churchill 57 0 Southern Churchill 57 0 O Superior Boundary Zone 62I/3); Manitoba Energy and Mines, Geological Services, Preliminary Compilation Map Series, scale 1:250 000. Stearn,C.W. O 57 0 Lynn Indian 57 0 Lynn Indian Lake Lake Ns Map 1999CAP-4, scale 1:50 000. Manitoba Round Table 1956: Stratigraphy and paleontology of the Interlake Group and Stonewall Lake Lake 54A TNB G 1999e: Capital Region Study: mineral resource potential and overburden 1994: Applying Manitoba's mineral policy; Manitoba Round Table on Formation of southern Manitoba; Geological Survey of Canada, Memoir KISSEYNEW River N UM River 54B LYNN LAKE thickness, Teulon (NTS 62I/6); Manitoba Energy and Mines, Geological Environment and the Economy, Sustainable Development Coordination 281, 162 p. 64C 64B 54D 54C N V SEISMIC SECTION B - B’ 64A Nelson Gd Services, Preliminary Map 1999CAP-5, scale 1:50 000. Unit, 71 p. Syme, E.C., Lucas, S.B., Zwanzig, H.V., Bailes,A.H.,Ashton, K.E. and Haidl, F.M. Nelson ASSEAN LAKE RESIDUAL TOTAL FIELD SHADED RELIEF Gammas BOUNDARY River O O River

1999f: Capital Region Study: geology and bedrock topography, Teulon (NTS 1995: Workbook on the Capital Region strategy; Manitoba Round Table on 1998: Geology, NATMAP Shield Margin Project Area, Flin Flon Belt, 100 0 98 0 Ns O O 62I/6); Manitoba Energy and Mines, Geological Services, Preliminary Environment and the Economy, Sustainable Development Coordination Manitoba/Saskatchewan; Geological Survey of Canada, Map 1968A, 54 0 54 0

Thompson ZONE Thompson 53O River PIKWITONEI River Map 1999CAP-6, scale 1:50 000. Unit, 59 p. Manitoba Energy and Mines, Map A-98-2, Saskatchewan Energy and LEGEND OS Gd 63N 63O 53N KISSEYNEW NORTHERN 1999g: Capital Region Study: mineral resource potential and overburden 1996: Applying Manitoba's Capital Region policies; Manitoba Round Table on Mines, Map 258A. Water Surface 1000 63P 53M GODS Hayes SUPERIOR O Hayes O s 55 0 thickness, Netley Marsh (NTS 62I/7); Manitoba Energy and Mines, Environment and the Economy, Sustainable Development Coordination Theyer, P. s 55 0 O od O od

0 800 0 55 G Berens River Domain Geological Services, Preliminary Map 1999CAP-7, scale 1:50 000. Unit, 47 p. 1998: Lake Winnipegosis komatiites; Manitoba Energy and Mines, Manitoba 55 G Flin Flon Gods Top of Lake Flin Flon Gods FLIN FLON SUPERIOR LAKE 1999h: Capital Region Study: geology and bedrock topography, Netley Marsh Matile, G.L.D. Mining and Minerals Convention '98, Winnipeg, Manitoba, November 12- Lake Winnipeg Sediments 600 Lake Ns (NTS 62I/7); Manitoba Energy and Mines, Geological Services, 1985: Quaternary geology of the Birds Hill area; Manitoba Energy and Mines 14, 1998, Program, p. 32. Gd 63K 63J 63I 53L 53K Ontario Preliminary Map 1999CAP-8, scale 1:50 000. MapAR84-5, 1:20 000. Thompson Nickel Belt Geology Working Group Top of Lake Agassiz 500 Ontario Sa Sa ska Sediments ska tc 2002: Capital Region Study (Winnipeg and surrounding areas) update and Matile, G.L.D.and Conley, G.G. 2001a: Geology of Perch Lake (63G/05), Eating Point (63G/06), Howell Point tc he Gd N he w stratigraphic drilling 2002, Manitoba; in Report of Activities 2002, 1979: Quaternary geology and sand and gravel resources of the Rural (63G/11) and Bracken Lake (63G/12) areas; Manitoba Industry Trade and 400 w a MOLSON LAKEIsland Top of Till a Island The Pas n WV UM The Pas n R V Manitoba Industry, Trade and Mines, Manitoba Geological Survey, p. 266- Municipality of Tache; Manitoba Energy and Mines, Mines Branch, Mines, Manitoba Geological Survey, Preliminary Map 2001FS-1, scale R ISLAND Lake UM V 350 63F Lake Cedar 272. Municipality Map Series, MapAR80-2. 1:100 000. Cedar 63G 53E LAKE O Gb O 63H Lake Bedrock Surface Lake O 53 53 Bezys, R.K. and Conley, G.G. Matile, G.L.D.and Groom, H. 2001b: Geology of the William Lake area (63G/14); Manitoba Industry Trade and O Saskatchewan O 300 Saskatchewan LAKE 0 LAKE 0 O 53 100O 98 1998a: Geology of the Silurian Interlake Group in Manitoba; Manitoba Energy and 1987: Late Wisconsinan stratigraphy and sand and gravel resources in the Rural Mines, Manitoba Geological Survey, Preliminary Map 2001FS-3, scale O 53 53 0 53 0 LAKE P Mines, Geological Services, Stratigraphic Map Series SI-1 (structure Municipality of Lac du Bonnet and Local Government District of 1:50 000. 250 LAKE WINNIPEG BERENS WINNIPEG A contour and isopach maps), scale 1:2 000 000. Alexander; Manitoba Energy and Mines,Aggregate ReportAR85-2, 44 p. 2001c: Geology of the Davidson Lake area (63G/13); Manitoba Industry Trade Phanerozoic Trans- Hudson Orogen Gb Gabbro 63C L 1998b: Geology of the Ordovician/Silurian Stonewall Formation in Manitoba; Matile, G.L.D.and Keller, G. and Mines, Manitoba Geological Survey, Preliminary Map 2001FS-4; 200 63B 63A 53D WINNIPEGOSIS RIVER Cenozoic Burntwood Group, undivided: WINNIPEGOSIS E BW Manitoba Energy and Mines, Geological Services, Stratigraphic Map 2002: Digital elevation model of southern Manitoba; Manitoba Geological scale 1:50 000. PHANEROZOIC greywacke- mudstone metaturbidite En Enderbite gneiss 150 O MESOZOIC Mesozoic Series OS-1 (structure contour and isopach maps), scale 1:2 000 000. Survey, available on-line at http://www.gov.mb.ca/itm/ mrd/geo Thorleifson, L.H. and derived migmatite 1998c: Geology of the Ordovician Stony Mountain Formation in Manitoba; /demsm/index.html (accessed November 2002). 1996: Review of Lake Agassiz history; in Sedimentology, geomorphology and Hudson Bay Basin Z Metavolcanic- metasedimentary 100 Paleozoic V Manitoba Energy and Mines, Geological Services, Stratigraphic Map McCabe, H.R. history of the central Lake Agassiz basin, J.T. Teller, L.H. Thorleifson, M E S O Z O I C O rocks, undivided 62N Superior Boundary Zone Series OSM-1 (structure contour and isopach maps), scale 1:2 000 000. 1967: Tectonic framework of Paleozoic formations in Manitoba; Transactions of G.Matile and W.C. Brisbin (ed.), Geological Association of Canada/ B B’ 50 62O 62P 52M I UCHI Precambrian O Williston Basin O 51 0 Archean basement migmatite- 1998d: Geology of the Ordovician Red River Formation in Manitoba; Manitoba the Canadian Institute of Mining and Metallurgy, v. 70, p.180-189. Mineralogical Association of Canada, Joint Annual Meeting, Winnipeg '96, 51 0 O C UM Ultramafic rocks O 0 Trans- Hudson Orogen TNBG 0 51 ENGLISH gneiss, undivided: retrogressed, Energy and Mines, Geological Services, Stratigraphic Map Series ORR-1 1978: Stratigraphic core hole and mapping program; in Report of Field Activities Field Trip Guidebook B2,Appendix, p. 55-84. 0 51 LAKE RIVER (Proterozoic- Archean) leucogranite to diorite in LAKE Superior Structural Province Granitold gneiss, undivided: granite (structure contour and isopach maps), scale 1:2 000 000. 1978, Manitoba Department of Mines, Resources and Environmental Todd,B.J., Lewis, C.F.M.,Thorleifson, L.H. and Nielsen, E. -50 PRECAMBRIAN composition, host to distinct bodies N 1998e: Geology of the Ordovician Winnipeg Formation in Manitoba; Manitoba Management, Mineral Resources Division, p. 64-67. 1997: Lake Winnipeg Project: cruise report and scientific results; Geological BIRD RIVER (Archean) to tonalite in composition, probably 62K 62J 62I 52L MANITOBA of orthogniess of various ages mixed with supracrustal rocks Energy and Mines, Geological Services, Stratigraphic Map Series SI-1 1980: Stratigraphic mapping and core hole program, southwest Manitoba; in Survey of Canada, Open File Report 3113, 656 p. MANITOBA Churchill Province Lithostructural belts & domains -100 ipeg Winnipeg River (structure contour and isopach maps), scale 1:2 000 000. Report of Field Activities 1980, Manitoba Energy and Mines, Minerals Todd,B.J., Lewis, C.F.M.,Nielsen, E., Thorleifson, L.H., Bezys, R.K. and Weber, W. Winn River River River Batholithic granite and Ospwagan Group supracrustal Intermediate gneiss with granitoid River River Brandon WINNIPEG OS Ns 1998f: The Precambrian in Manitoba; Manitoba Energy and Mines, Geological Division, p. 70-73. 1998: Lake Winnipeg: geological setting and sediment seismostratigraphy; -150 Brandon RIVER granitoid gneiss rocks, undivided: clastic and phases Assiniboine Services, Stratigraphic Map Series PC-1 (structure contour and depth to 1986: Stratigraphic mapping and industrial minerals core hole program; in Journal of Paleolimnology, Special Issue: Paleolimnology of Lake Assiniboine Superior Province WINNIPEG Sedimentary gneiss/migmatite chemical metasediments and -200 WINNIPEG associated metavolcanic rocks Precambrian maps), scale 1:2 000 000.. Report of FieldActivities 1986, Manitoba Energy Preliminary report on Winnipeg, Canada, v. 19, p. 215-244. 62F 62G 62H 52E

CENOZOIC Red WABIGOON Red Granite- greenstone O Winnipegosis Belt Assemblage, SYMBOLS 1998g: Lower to Middle Paleozoic stratigraphy of southwestern Manitoba; 8th Ordovician-Silurian boundary rocks in the Interlake area, Manitoba, Underwood McLellan andAssociates Limited (UMA) O O 49 0 -250 O 49 0 49 0 WV undivided: ultramafic to mafic International Williston Basin Symposium, Regina, Saskatchewan, Canada; Bulletin of the British Museum of Natural History (Geology), v. 43, 1976: Aggregate resources of the Winnipeg region; Manitoba Department of 49 0 North Dakota Minnesota Diabase, gabbro dike, undivided October 1998, Field Trip #1 Guidebook, 92 p. p.255-257. Mines, Resources and Environmental Management, Open File Report North Dakota Minnesota volcanic flows (Molson swarm): based on drill core -300 O O O 1999: Manitoba Stratigraphic Database and the Manitoba Stratigraphic Map McGregor, C.R., Bezys, R.K. and McCabe, H.R. OF77-4, 53 p. O O O

100 0 96 0 92 0 information and strong linear 100 0 96 0 92 0 Superior Province Series; Manitoba Energy and Mines, Geological Services, Open File 1990: Subsurface Precambrian structure of the Grand Rapids and Wekusko WestAntarctic Ice Sheet Working Group -350 aeromagnetic signatures Report OF98-7, CD-ROM. Lake map sheets (NTS 63G and 63J); Manitoba Energy and Mines, 1994: The West Antarctic Ice Sheet (WAIS) initiative illustrated summary; -400 G Granite to granodiorite Mafic intrusion: based on drill core Bezys, R.K., Fedikow, M.A.F.and Kjarsgaard, B.A. Geological Services, Preliminary Map 1990M-2, scale 1:250 000. National Aeronautics and Space Administration, available on-line at information and weak to moderate 1996: Evidence of Cretaceous(?) volcanism along the Churchill-Superior McMartin, I. http://igloo.gsfc.nasa.gov/wais/illus-sum/illus_sum.html (accessed -500 linear aeromagnetic signatures Boundary zone, Manitoba (NTS 63G/4); in Report of Activities 1996, 2000: Quaternary geology and environmental geochemistry of the Flin Flon November 2002). Gn Granite to granodiorite gneiss O O Every possible effort has been made to ensure that the information presented on this map is accurate. Manitoba Energy and Mines, Geological Services, p. 122-126. region, Manitoba and Saskatchewan; Ph.D. thesis, Carleton University, 53 0 53 0 Fault, inferred O O However, the Province of Manitoba and Manitoba Industry, Trade and Mines do not assume liability Ottawa, 289 p. 100 0 98 0 for any errors that may occur. References are included for users wishing to verify information. Gd Granodiorite to tonalite Domain boundary