metallic metals - Government of Manitoba

Group in southeast Manitoba. One or two smalloutcrops occur along the north shore ofWanipigow Lake (C 1-2) in a greywacke-argillitesequence, and there are a few scattered outcrops 4to 11km to the east-southeast, north of theWanipigow River (C 3-4). The best outcrops ofmagnetic iron formation are found however atWallace Lake, where they are associated witharkose, grit and conglomerate of the Rice LakeGroup. Outcrops (C 5-6) can be seen on thenorthwest and south shores of the largest island,and the shorelines to the north and east. The ironformation extends eastward along the north side ofthe Wanipigow River. The outcrops (C 7), about 3km east of Wallace Lake and a few hundred metresnorth of the river, are underlain to the south byquartzite and gabbro. Between these rocks and theriver there are some striking outcrops of gossan(see Goethite), derived from theweathering of ironsulphides that occur with garnet, magnetite andactinolite.Argillite of the Rice Lake Group, with minorgreywacke and lesser amounts of chert and ironformation, strikes northwest from Gem Lake toLong Lake (C 8) ; iron formation is exposed on theshore, southeast to the westernmost tip of GemLake (C 9). Iron I formation also occu rs with schistand paragneiss around Garner Lake andnorthwestward to Beresford and Moore Lake. Aband of iron formation a few hundred metres eastof southern Beresford Lake (C 10) strikesnortheasterly for about 1.5 km . Afirsthanddescription of these and other outcrops (Cll) inthis area was given by Russell as follows :... iron formation with abundant ferruginouslimestone was found near the north end of the10Garner Lake-Beresford Lake portage. On a ridge tothe east of the first rock encountered southwardfrom Beresford Lake (along the winter road) fivemore beds of iron formation were found. Traverseseast of Beresford Lake and Moore Lake show thatthis wide zone of iron formation beds is continuousnorthward and curves parallel to the east shores ofBeresford Lake and Moore Lake ... (East of the southend of Moore Lake) eight parallel bands of ironformation are exposed. Near Moore Lake the ironformation is highly siliceous and composed ofuniform beds of quartzite (one half to one inchthick) separated by thin beds (one eighth to onequarter inch thick) of granular magnetite... (A littiefurther east) five-foot bands of nea rly puremagnetite were seen ... between massive bodies ofdiorite.References: Marr 1971 ; McRitchie 1971a, p 112,1971b; Phillips 1978, map D; Russell 1952b;Weber 1971aIn the SNOW LAKE AREA, iron formation hasbeen recorded in the Grass River Provincial Park,associated with a pyroclastic-greywacke sequence.The best exposure (F 1) is in a railway cutting nearmilepost 11 , about 2 km west of the railway bridgeover the Grass River. Large, dark grey outcropsshow thin cherty and iron-rich bands, only a fewmillimetres thick, associated with volcanic schists.The iron-rich bands consist mainly of magnetite butiron sulphides are also present. Magnetite-rich ironformation again crops out on the east bank of theGrass River (F 2) about halfway between the railwaybridge and Iskwasum Lake, which is another 5 kmdownstream. Trenches on the west side of the river,