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ONTARIO DEPARTMENT OF MINES AND NORTHERN AFFAIRS
PRELIMINARY GEOLOGICAL MAP No. P.627 Black Bay Peninsula and Vicinity EDWARD ISLAND SHEET DISTRICT OF THUNDER BAY
Scale I inch to k, mile NTS Reference: 52 A/7, 52 A/10 ODM-GSC Aeromagnetic Maps: 2115G, 2116G ODM Geological Compilation Map: 2137
o
Hornick Cove
INDEX MAP
LEGEND FOR BLACK BAY PENINSULA AND VICINITY
CENOZOIC RECENT Stream, lake and swamp deposits PLEISTOCENE Glacial, glaciofluvial and glaciolacustrine deposits
UNCONFORMITY
PRECAMBRIAN PROTEROZOIC KEWEENAWAN LATE MAFIC INTRUSIVE ROCKS3 7 Diabase, undifferentiated 7a Fine-grained diabase 7b Ophitic diabase
INTRUSIVE CONTACT
MIDDLE MAFIC INTRUSIVE ROCKS MOSS LAKE GABBRO3 Louse Cove 6 Gabbro, undifferentiated 6a Medium- to coarse-grained gabbro 6b Fine-grained gabbro 6c Pegmatitic gabbro 6d Granophyre 6e Anorthosltic gabbro, gabbroic anorthosite 6f Foliated gabbro 6g Porphyritic gabbro
INTRUSIVE CONTACT
OSLER GROUP EARLY MAFIC INTRUSIVE ROCKS 5 Diabase
PORPHYRITIC FELSIC VOLCANIC ROCKS3 4a Red quartz porphyry 4b Red quartz-feldspar porphyry 4c Red feldspar porphyry 4d Grey feldspar porphyry 4e "Thunder Egg" porphyry
SEDIMENTARY ROCKS C 3a Sandstone 3b Conglomerate 3c Argillite, siltstone
MAFIC VOLCANIC ROCKSb 2a Grey to green massive basalt 2b Ophitic basalt 2c Porphyritic basalt 2d Red basalt 2e Amygdaloidal basalt 2f Flow breccia 2g Agglomerate 2h Tuff 2j Glomeroporphyritic basalt
SIBLEY GROUP l Red fine-grained sandstone
a The rocks in these groups are subdivided lithologically and the order does not imply age relationships within the groups
b The rocks in this group are subdivided lithologically and the order does not imply age relationships within the groups or among the groups. c. Occurs locally as small interbeds with the volcanic rocks.
Note: Where suggested colour is not shown in box indicates unit is not present on this sheet.
GEOLOGICAL AND MINING SYMBOLS
Small bedrock outcrop. Geological boundary, position interpreted. Area of bedrock outcrop. Kidd Pt. Fault (assumed). Bedding, top unknown; Jointing; (inclined, O (inclined). vertical). Direction of palaeocurrent. Vein. Width in inches. Geological boundary, observed. Shaft.
George
O O O O
* /w ^~,s S
Magnet
______Location and Access: The north end of Edward Island is 29 miles (4.6 km) east of Thunder Bay and 44 miles (70 km) southwest of Nipigon. Access is by boat or float-equipped aircraft. Boats may be launched in Nipigon or from several localities on the adjacent Sibley Peninsula. Aircraft can land in Channel some of the sheltered areas near the islands. Mineral Exploration: Over the years several companies and individuals have been active in reconnaissance exploration for native copper deposits similar to those found in the Keweenaw Peninsula of Upper Michigan.
Exploration for silver has been carried out on Edward and Porphyry Islands in areas approximately on strike with the Silver Islet deposits.
Monarch Gold Mines Limited put down four diamond drill holes totalling 1,018 feet (310 m) to investigate a calcite vein at the south end of Edward Island in 1962. Only traces of silver were found.
There are some old pits with reported minor copper mineralization on Copper Point. Edward General Geology: The relatively flat-lying red sandstone on Grey Island is considered to belong to the Sibley Group. The rock is fine-grained and contains numerous buff "reduction spheres" up to l inch (2.5 cm) in diameter.
The overlying Osler Group of relatively flat-lying volcanic and sedimentary rocks underlies most of the map-sheet. On the Edward Island sheet the Osler Group appears to consist of a near basal sedimentary unit about 50 feet (15 m) thick overlain by basalt flows with intercalated sedimentary and pyroclastic rocks. The estimated thickness is about 2,400 calc veins-10-25 feet (730 m) which compares with the total thickness of 6,200 feet (1,900 m) found on Fluor Island (Mcilwaine et al. 1971). The thickness of individual flows is variable; thin flows in the l foot to 3 feet (30 cm to 60 cm) range are amygdaloidal throughout and the thicker flows have a massive central portion with amygdaloidal tops and bottoms. Pipe amygdules occur locally at the bottoms of flows. Common amygdule minerals include laumontite, pumpellyite, calcite, quartz, hematite and agate. The massive basalt is generally fine-grained greenish-grey; porphyritic basalt is abundant on Porphyry Island and on the east shore of Edward Island. Ophitic basalt is common on the islands between Phlox and Tunnel Islands. Diabase on Monk Island is possibly a sill related to Osler volcanism. s l a n dvt Sedimentary rocks are mostly fine-grained red sandstones; the sandstone © ©. ,*\ * along the shore of Osler Bay is predominantly white and crossbedded. Palaeocurrents, as indicated by meagre data from crossbedding, flowed towards the southeast; this direction is supported by the orientation of primary current lineation.
The volcanic rocks are intruded by a swarm of diabase dikes with a prominent northeast trend. The dikes are generally fine-grained and dark grey; locally the texture is ophitic as with the large northwest-trending dike. Some of the small dikes in the l foot to 2 feet (30 cm to 60 cm) range may be related to Osler volcanism and are autointrusive.
Structural Geology: The Osler volcanic rocks strike from N20E to N70E and dip 4-11SE. Shearing in the rocks along the south shore of Edward Harbour provides evidence for a fault which, as indicated by topography, appears to continue inland across Edward Island. Faulting may also have occurred between the islands, but this is difficult to determine.
Economic Geology: Many of the large native copper deposits of Michigan are found in fragmental flow tops .(Butler and Burbank 1929). Fragmental flow tops in the Black Bay Peninsula area are not common and it is probably because of this that exploration has not been successful. Minor amounts of finely disseminated copper have been observed in boulders of "red-beds" Horbd along the beach on the Black Bay side of the peninsula. At the north end of Porphyry Island is a series of calcite veins 4 to Little 6 inches (10 cm to 15 cm) thick and striking N74E parallel to a diabase dike. No mineralization was observed during mapping but Tanton (1931) reports Gi bra l tar disseminated chalcocite and chalcopyrite. Rock On the southeast shore of Edward Island are two old shafts, one of which (No. 1) is reported to be 35 feet (10.7 m) deep (Tanton 1931). Tanton reports that some native arsenic came from this shaft. Both of these shafts were put down on calcite veins which trend close to north and contain chalcopyrite, galena, sphalerite and local argentite and native silver (Tanton 1931). No mineralization was observed during the field season.
Agates of excellent quality and suitable for lapidary work are found locally in amygdules of the basalt and on the beaches.
Selected References:
Butler, B.S., and Burbank, W.S., 1929: The copper deposits of Michigan; United States Geol. Surv., Prof. Paper 144, Horseshoe Mcilwaine, W.H., Wallace, Henry, d©Apollonia, S.J., and Keeler, R.G., 1971: Black Bay Peninsula and Vicinity, Fluor Island Sheet; ODMNA, Prel. Geol. Map No. P.624. Tanton T.L., 1931: Fort William and Port Arthur, and Thunder Cape map areas,©Thunder Bay District, Ontario; Geol. Surv. Canada, Mem. 167.
Hardscrabble orphyry METAL AND MINERAL REFERENCE
calc ...... Calcite Cu ...... Copper py ...... Pyrite PORPHYRY ISLAND PROVINCIAL PARK LIST OF PROPERTIES WITHDRAWN FROM 1. Cross, H. STAKING. 2. Cross, J.A. 3. Wilson, R.C., Estate
SOURCES OF INFORMATION O O Geology by W.H. Mcilwaine, Henry Wallace and S.J. d©Apollonia, bo 1970. fi Basemap derived from Forest Resources Inventory Maps, Ontario S -48 0 20©30" Department of Lands and Forests. 480 20©30"- Dreadnought Magnetic declination 00 00 T , 1970.
Pt. Porphyry Issued 1971. © :
ODMNA 4685 ONTARIO DEPARTMENT OF MINES AND NORTHERN AFFAIRS
PRELIMINARY MAP P.637 GEOLOGICAL SERIES OTUKAMAMOAN LAKE AREA (East Part)
DISTRICTS OF RAINY RIVER AND KENORA
Scale l inch to \ mile
NTS Reference: 52 C/15, 52 F/2 ODM-GSC Aeromagnetic Maps: 1151G, 1152G ODM Geological Compilation Series Map: 2115
LEGEND
CENOZOIC PLEISTOCENE AND RECENT Sand, gravel, boulders, clay
UNCONFORMITY
PRECAMBRIAN -.MAFIC DIKE ROCKS 7 Undifferentiated mafic dikes
INTRUSIVE CONTACT
RYCKMAN LAKE STOCK 6 Undifferentiated 6a Porphyritic granite 6b Diorite, quartz diorite
CONTACT INDETERMINATE
GRANITIC ROCKS AND FELSIC DIKE ROCKS 5 Undifferentiated 5a Massive granite, coarse- to medium-grained 5b Foliated granite, non-porphyritic 5c Gneissose granite 5d Diorite, quartz diorite 5e Porphyritic granite, massive and foliated 5f Pegmatite and aplite
INTRUSIVE CONTACT
ROCKY ISLET BAY AND WELLER LAKE COMPLEXES 4 Undifferentiated 4a Syenite, monzonite, quartz monzonite 4b Diorite, syenodiorite 4c Porphyritic monzonite 4d Mylonitized monzonite or porphyritic monzonite 4e Granite 4f Brown biotitic monzonite
INTRUSIVE CONTACT
FELSIC TO INTERMEDIATE METAVOLCANICS 3 Undifferentiated 3a Tuff breccia 3b Tuff and lapilli tuff 3c Rhyolitic to dacitic flows or volcanoclastic rocks 3d Quartz-biotite schist, occasionally garnetiferous 3 -- , -- f -. ."-"©\ f \ /\V©S*y*:\ ,N /© v l IF Iron formation x x \ f \ ; -k-- r-^ f " \( SIF Sulphide-bearIng iron formation \ -- \ ©^ ! \ -© ! ©^ \ ©©- --9 \ i© i-J^7J .\V f. i ii -\\ r\ \ ---- j \\s-\_ f ;©. * -, j jr** ;- \\ ^f fl- ©-\tA \ si ,© ©f**; . ; 7•y \ .© " w INTERCALATED IN PART ,MAFIC TO INTERMEDIATE METAVOLCANICS 2 Undifferentiated *, \ V f V"J v 2a Foliated amphibolite and netabasalt J N --© \ 2b Amphibolite migmatite ^\^:m 2c Massive amphibolite, metabasalt, and hornblendite" 2d Amphibolite and metabasalt with pillow remnants _ __ - 2e Tuff breccia and lapilli tuff 2f Amygdaloidal metabasalt 2g Diorite b 2h Garnet amphibolite 2j Actinolite and(or) chlorite schist 2k Graphitic schist 2m Porphyritic metabasalt
INTERCALATED IN PART
METASEDIMENTS l Undifferentiated la Ojjartz-biotite schist, occasionally garnetiferous Ib Migmatitic quartz-biotite schist c
IF Iron formation
Breccia Mostly derived from tuff breccia, tuff and lapilli tuff, but probably in part from sedimentary rocks. May be in part intrus Ive . May be in part derived from tuffaceous rocks,
GEOLOGICAL AND MINING SYMBOLS
-e" Glacial striae. Fault; (observed, assumed). Small bedrock outcrop. Lineament. Area of bedrock outcrop. Jointing; (inclined, Bedding, top indicated by vertical). arrow; (overturned). Drag folds with plunge. Lava flow; top (arrow) from pillows shape and packing. Multiple folding; (vertical, inclined axial Gneissosity, {horizontal, planes). inclined, vertical). Anticline, syncline with Foliation; (inclined, plunge. vertical, dip unknown). O DM Drill holes. Lineation with plunge. \ Vein. Geological boundary, observed. MA Magnetic attraction. Geological boundary, position interpreted.
MARGINAL NOTES FOR P. 636 AND P. 637
Location and Access: Otukamamoan Lake is situated about 35 miles northeast of the town of Fort Frances. At present no roads connecting with public highways occur in the map-area. The lumber road extending northward between McTaggart and Cuttle Lakes to Tuprnan Lake terminates one half mile south of the map-area on the north shore of Macdonald Inlet of Rainy Lake. During the summer of 1970 the Ontario Department of Highways surveyed the road location passing between Tupman and Big Sawbill Lakes; this road, which in part will follow the existing lumber road, is presently under construction at its southern end where it connects with Highway 11 in the vicinity of Nickel Lake,
Otukamamoan Lake may be reached from Redgut Bay of Rainy Lake by two short portages on the Trout River. Cuttle and Obikoba Lakes may be reached from Northeast Bay of Rainy Lake by a short portage on the Big Canoe River.
Mineral Exploration: In 1955, a geological and scintillometer survey was carried out by Pioneer Consultants Limited for Bunker Hill Extension Mines Limited and in 1957 geological mapping, followed by a total of 1,170 feet of drilling over 12 holes, was done by Rainy Lake Mining Limited, both on claim groups located near Otter Bay of Mainville Lake (ODMNA). No radioactive anomalies of any significance were discovered on the tormer property. On the latter property, disseminated molybdenite and chalcopyrite were found in granitic rocks, and fairly strong radioactivity was noted in pegmatite dikes. A grab sample taken by Rainy Lake Mining Limited fro one of the: pegma t i t c dikes was found on analysis to contain 0.45 percent l^Og (ODMNA).
During the summer of 1970, Phelps Dodge Corporation of Canada Limited carried out geophysical surveys on a number of claim groups in the vicinity of Porter Inlet and Otukamamoan, Big Sawbill, Little Sawbill and Grimshaw Lakes.
General Geology: Previous mapping was carried out toward the end of the 19th century by Lawson (1888) and Coleman (1895).
All bedrock is of Archean age . Metavolcanics and metasediments appear to be the oldest rocks in the area. Mafic to intermediate metavclcanics occur extensively in the north half of the nap-area. They consist cf basaltic and andesitic lavas and intermediate tuff breccias which have beer metamorphosed Lo hornblende schists and amphibolites , both of which are sometimes garnetiferous. Minor felsic bands and lenses occur scat 1 1? re d within the more mafic sequence , while thicker and more continuous felsic units occur in the Tuprnan Lake Antiform, on the east side of Big Sawbill Lake, along the southwest arm of Winkle Lake and on the west side oC Otukamamoan Lake. In all of these areas the felsic units lie within the more mafic sequence, though on Otukamamoan Lake this may bc due to infolding. Felsic metavolcanics are derived from tuffs, lapilli tuffs, tuff breccias, and possibly minor rhyolitic flows. Quartz-biotite schists, occasionally garnetiferous, are closely associated with the felsic I f-i-^ -©W luetavolcanics } particularly in the Tupman Lake Antiform and on Otukamamoan Lake. They appear to be derived for the most part from tuff breccia, tuff, and lapilli tuff, but their layered nature in many places indicates that at least some of these schists may be of sedimentary origin. An independent sequence of %-C .4*?W undoubted sedimentary rocks (quartz-biotite schists) containing graded beds \i in i\ - © i i , occurs in the southwest, in the vicinity of Otter Bay. The stratigraphic u ; ©J k relationship of these to the volcanic-sedimentary sequence in the west of the inap-area is unknown. Magnetite iron tornation occurs within quartz-biotite schists south of Otter Bay, and also east of Big Sawbill Lake. La fie A " \! V Granitic rocks of several ages underlie at least two-thirds of the map- A - area, including most of the country north of Porter Inlet and south o: \ \ © 4 Otukamamoan Lake previously designated as metavolcanics (Davies and Tyyslak 1967).
The monzonitic-dioritic Rocky Islet Bay Complex (Lawson 1913; Harris 1969, 1970) and Weller Lake Complex intrude the volcanic-sedimentary sequence. At Pickwick Lake an intrusive breccia ?,one occurs along the contact between the Weller Lake Complex and mafic to intermediate metavolcanics.
Granites intrude both the complexes and the volcanic-sedimentary sequence. These granitic rocks vary from massive to foliated to gneissose, and from medium-grained to coarse-grained and porphyritic. Upon approach to contacts with netavolcanics , particularly in the Tupman Lake Antiform and along the southwest shore of Otukamamoan Lake, granites pass into migmatites containing progressively greater amounts of mafic constituents. Coarse, foliated porphyritic granites ueeur between Porter Inlet in the south and Cherry Lake in the north. Porphyritic granites of the Ryckman Lake stock are considered to be distinct from the other granitic rocks for several reasons. Firstly, they are largely massive, or at the most, weakly foliated especially at the borders of the stock. Secondly, no migmatites are associated; the stock possesses a hybrid outer border zone of diorite and quartz diorite and is scattered with small mafic inclusions. Thirdly, although granites of the stock appear to be continuous with those to the south, lack of outcrop west of Cherry Laky prevents confirmation; they may be completely surrounded by the volcanic rocks which they intrude. Fourthly, pegmatites and aplites associated with both granitic rocks and rocks of the Weller Lake Complex do not occur in the Ryckman Lake stock. Three late mafic dikes have been found, two on the southwest shore of Otukamamoan Lake, and one very minor dike on the west shore of Weller Lake.
Structural Geology : westward- f ac ing pillows at Pickwick Lake i indicate that the Tupman Lake fold may be an anticline, while similarly westward-facing pillows at Winkle Lake indicate a syncline between Winkle Lake and the Tupman Lake fold. This syncline may lie along the southwest arm of Winkle Lake, and continue southeastward beneath the middle bay of Otukamamoan Lake. The complexity of foliations and lineaLions in the triangular-shaped area of felsic metavolcanics lying between Crowrock Bay, Cherry Lake and Otukamamoan Lake indicates the presence of three synf orms , all plunging towards each other, the northerly one being continuous with the syncline that may underlie the middle bay of Otukamamoan Lake . Southward towards the east-west-trending Quetiuo Fault zone, which lies immediately to the south of the present map-area (Harris 1969, 1970) and eastward towards Crackshot Lake and Spawn Inlet, deformation and granitic intrusion increase in intensity, while metavolcanics become increasingly migmatitic. All granitic rocks appear to be syntectonic, except those of the Ryckman Lake stock which are late tectonic. The marked deflection in foliation towards the southwest and associated Z-shaped drag folding along the southern edge of the map-area are attributable to dextral strike-slip movement on the C^uetico Fault. Economic Geology: Rusty pyrite gossans occur on the small island in the narrows immediately north of Deer Island in Redgut Bay. The island lies in an Intensely brecciated zone related to the Spawn Inlet Fault. A 15-foot chip sample was found to contain chromium, copper, titanium and vanadium, all in trace to low amounts, low amounts of manganese, and 12.57c iron (except where Indicated, this and all other qualitative specLrographic analyses are by the Laboratory and Research Branch, Ontario Department of Mines and Northern Affairs). A number of small pyrite and pyrrhotite gossans present in hornblende schist on the south bank of Turtle River at Crooked Marrows (entrance to Redgut Bay) contain in addition to iron, trace amounts of chromium, copper and vanadium, and slightly higher amounts of manganese and titanium.
A sulphide (pyritiferous ) iron formation Interlayered with metavolcanics can be traced along strike for some 200 feet on the northwestern shore of the south bay of Otukamamoan Lake, and contains, in addition to iron, trace amounts of chromium, copper, manganese and titanium. Throughout the map-area, pyrrhotite occurs in both felsic and mafic metavolcanics, along with pyrite, and both are usually disseminated. However, small areas of magnetic attraction ;©i-a fefe j© around the Tupman Lake Antiform appear to be related to more concentrated amounts, mostly within felsic metavolcanics. Magnetite occurs in a massive mafic Intrusive or basaltic flow on the small group of islands at the east end of Crowrock Bay of Otukamamoan Lake. Banded quartz-magnetite iron formation on the small peninsula jutting from the shore of Otukamamoan Lake immediately south nf Big Island is intensely injected by granitic and pegmatitic dikes. Magnetite iron formation interlayered with quartz-biotite schists on the flanks of the Tupman Lake Antiform has a low iron content but is in part responsible for anomalies delineating the fold structure on airborne magnetic survey maps (ODM-GSC). A very pronounced anomaly coincides with the somewhat richer iron formation south of Otter Bay.
Uranium in pegmatite dikes and molybdenite and minor chalcopyrite in granitic rocks have been reported in the Otter Bay -Macdonald Inlet area by Rainy Lake Mining Limited. Three quarters of a mile northeast of Little Sawbill Lake and one quarter of a mile north of the Indian Reserve north boundary line, trace amounts of molybdenite occur within metavolcanics associated with graphitic schists.
References : Coleman, A. P., 1895: Map 5b, Southeastern part of the Rainy River District, accompanying Second report on the gold fields of western Ontario; Ontario Bur. Mines, Vol. 5, Sec. 2, p. 47-106. tS"~ Ut^/ Davies, J. C., and Pryslak, A. P., L967: Kenora-Fort Frances Sheet; Ontario Dept.© Mines, Geological Compilation Series, Map 2115, scale l inch to 4 miles (Compilation 1963-1965). Harris, F. R. , 1969: Watten Township (West Half), District of Rainy River; Ontario Dept. Mines, Prelim. Geol. Map P. 522, scale l inch to k mile. 1969: Watten Township (East Half), District of Rainy River; ______, Ontario Dept. Mines, Prelim. Geol. Map P. 523, scale l inch to k mi ______1970: Rainy Lake area (West Half), District of Rainy River; Ontario Dept. Mines, Prelim. Ceol. Map P. 586, scale l inch to \ mile. ______1970: Rainy Lake area (East half), District of Rainy River; Ontario Dept. Mines, Prelim. Ceol. Man P. 587, scale l inch to k mile. Lawson, A. C., 1888: Report on the geology of the Rainy Lake region; Geol. Surv.© Canada, Ann. Rept. , Vol. 3, pt. l, p.Fl-F182. ______1913: The Archean Geology of Rainy Lake restudied; Geol. Surv. Canada, Memoir 40, 115p. ODM-GSC 1961: Little Turtle Lake, Rainy River District, Ontario; Ontario Dept. ©Mine s-Geol. Surv. Canada, Aeromagnetic Series, Map 1151G, scale l inch to l mile. Survey, 1961. ______1962: Mainville Lake, Rainy River District, Ontario; Ontario Dept. Mines-Geol. Surv. Canada, Aeromagnetic Series, Map 1159G, scale l inch to l mile. Survey, 1961. ODMNA: Assessment work files; Ontario Dept. Mines and Northern Affairs, Resident Geologist©s office, Kenora. MINERAL REFERENCE FOR P. 636 AND P. 637
hem ...... Hematite py Pyrite mag ...... Magnetite pa Pyrrhotite mo ...... Molybdenite qv Quartz vein
Resort LIST OF PROSPECTS
ADJOINS P.587 1. Bunker Hill Extension Mines Limited, Otter Bay [l955J 2. Rainy Lake Mining Limited, Otter Bay Q.957J
Date in square brackets indicates year of last major work.
SOURCES OF INFORMATION Crowrock 48 0 47©00" Geology by C.K. Blackburn and assistants, 1970. Geology is not tied to surveyed lines. Aeromagnetic maps 1151G, 1152G, 1159G, 1160G, Ontario Department of Mines and Geological Survey of Canada, 1961, 1962. Base maps derived from maps of the Forest Resources Inventory Ontario Department of Lands and Forests, with minor revisions by C.E. Blackburn. Magnetic declination approximately 5 0 E, 1970.
Issued 1971. ODMNA 4707