Ontario Mineral Inventory

Ontario Geological Survey
Permanent Link to this Record: MDI42L06NE00002

Record: MDI42L06NE00002

General

Commodities

Primary Commodities: Gold

Secondary Commodities: Copper, Zinc, Silver

Location

Township or Area: O Sullivan Lake Area

Latitude: 50° 26' 31.01"    Longitude: -87° 5' 24.12"

UTM Zone: 16    Easting: 493607   Northing: 5587774    UTM Datum: NAD83

Resident Geologist District: Thunder Bay North

NTS Grid: 42L06NE

Point Location Description: Minesite

Location Method: Conversion from MDI

Access Description: The mine is located on O'Sullivan Lake, 40 km northwest of Nakina, Ontario. The property can be reached via all-weather Highway 584 which extends north from Highway 11 at Geraldton, Ontario, to a point at the intersection of Highway 643 approximately 8 km west of Nakina. Continue northwest along Highway 643 to the northwest shore of O'Sullivan Lake where the mine road follows an east-northeasterly direction to Osulake Peninsula.

Exploration History

1935: Original 9 claims staked by J. Miller and optioned to McIntyre Porcupine Mines, who conducted drilling. 1945: Restaked by J. Miller and transferred to D.F. Hurd. Claim group taken over by Osulake Mines Ltd. An extensive diamond-drilling program revealed the presence of good gold values in a mineralized zone in sheared tuffs and quartz porphyry. 1947: Osulake Mines Ltd. sunk a shaft and the mineralized zone was developed on the 100 foot level. 1950: The company was reorganized and renamed to Lake Osu Mines Ltd. 2nd level dev't at 300 feet. 1960: Mag survey and diamond-drilling carried out. 1964-65: Louanna Gold Mines Ltd. drilled 10 holes totalling 1835.7 m. Extensive underground drilling was carried out. 1973-74: Consolidated Louanna Gold Mines Ltd. dewatered the underground workings and the shaft was sunk to approximately 129.2 m with the establishment of a third level. Underground drilling showed mineralization to at least the 129.2 m horizon. 1974: Mattagami Lake Mines Ltd. carried out VLF-EM, horizontal loop electromagnetic, and magnetic geophysical surveys. 1981-82: Over 13 230 m of surface and underground drilling had been done on the property by late 1981, together with 1 046 m of lateral dev't work. A decline was sunk in the vicinity of the old shaft, to a depth of 15.4 m below the 2nd level. A 200 ton/d mill was installed. As of Sept 1982, mining and milling operations had ceased. 1983: As of Sept., the mine was dewatered and the mill was concentrating 190-200 t/day. Two stopes were in production and a third being dev't. 1984: Mill closed in October 1984. Lacana Mining Corp. carried out line cutting, geophysics, geological mapping, 2909.3 m of diamond drilling. 2007-08: Superior Canadian Resources Inc. carried out magnetic and VLF-EM surveys, a MMI soil geochemical survey, and drilled 21 DDH totalling 3775 m.

Assessment Work on File

Geology

Province: Superior

Subprovince: Wabigoon

Terrane: Eastern Wabigoon

Belt: Onaman-Tashota

Geological Age: Archean  

Geology Comments

Dec 07, 2005 (B Nelson) - Rocks exposed on the property are chiefly pillowed lavas and metadiabases, which are cut by a variety of quartz porphyry dykes and several diabase dykes. Two narrow bands of highly sheared, more or less silicified, and mineralized tuffs occur interbedded with lavas east of the bay. Gold mineralization occurs in two parallel quartz veins hosted in a quartz-feldspar porphyry emplaced in sheared mafic tuffs. Veins are lenticular, laminated or brecciated and average <2 m in width. Veins are of multiple generations. The underground work and much of the diamond-drilling have been directed to investigate an occurrence of mineralization in sheared tuffs and quartz porphyry. The only surface outcrop is a complex mixture of schist and sheared quartz porphyry. Some of the quartz is well mineralized with sulphides, and some visible gold is exposed.

Lithology

Lithology Comments

Dec 07, 2005 (B Nelson) - Rocks exposed on the property are chiefly pillowed lavas and metadiabases, which are cut by a variety of quartz porphyry dykes and several diabase dykes. Two narrow bands of highly sheared, more or less silicified, and mineralized tuffs occur interbedded with lavas east of the bay.

Mineralization

Mineralization Comments

Dec 07, 2005 (B Nelson) - Consolidated Louanna, from 1981 to 1982, outlined the original mineralized zone as 152.6 m of ore in two parallel veins on the first level, averaging 0.41 oz/ton Au. A similar length was outlined on the second level where the grade averaged 0.48 oz/ton Au across 1.8 m. A new mineralized zone was encountered in underground development during 1981, none of which was included in any earlier tonnage estimates. SEE OFR 5630 FOR FURTHER INFORMATION ON THIS OCCURRENCE.

Jun 27, 2019 (Therese Pettigrew) - Gold mineralization occurs in two parallel quartz veins hosted in a quartz-feldspar porphyry emplaced in sheared mafic tuffs. Veins are lenticular, laminated or brecciated and average <2 m in width: veins are of multiple generations. A white massive quartz intrudes the typically dark laminated and/or brecciated quartz (both generations of quartz are auriferous). A third-generation barren quartz (carbonate) vein cuts the other veins. Mineralization consists of arsenopyrite, pyrite, pyrrhotite, sphalerite, galena, and gold (Mason and White, 1986). Consolidated Louanna, from 1981 to 1982, outlined the original mineralized zone as 152.6 m (496 feet) of ore in two parallel veins on the first (150 foot) level averaging 0.41 ounces per ton gold (cut). A similar length was outlined on the second (300 foot) level where the grade averaged 0.48 oz per ton gold (cut) across 1.8 m (5.8 feet), (The Northern Miner, 1981, September 24, p. 4). A new mineralized zone was encountered in underground development during 1981, none of which was included in any earlier tonnage estimates. The zone was intersected in four short drill holes put out from the production ramp as well as previous holes drilled from surface. Drilling results indicated a section that assayed 1.37 oz per ton gold (uncut) or 0.82 oz per ton gold (cut) across a core length of 7.7 m (25 feet). Follow up drilling from the underground ramp on a section 24.6 m (80 feet) further east intersected 0.56 oz per ton gold across 0.98 m (3.2 feet), with a second hold cutting 0.95 m (3.1 feet) assaying 2.57 oz per ton gold, (The Northern Miner, 1981, September 24, p. 4 and November 19, p. 8). Sample 81-MCL-2 assayed 1.48 opt Au and 0.38 opt Ag. Sample 81-MCL-3 assayed 0.48 opt Au and 0.16 opt Ag. Sample 83-MCL-1 from the 250-foot sublevel assayed 2.70 opt Au (Mason and White, 1986).

Alteration Comments

Dec 07, 2005 (B Nelson) - Carbonate alteration occurs adjacent to the quartz veins. Locally, the veins may pinch out, leaving only the zone of carbonate alteration.

Mineral Record Details

Site Visit Information

Date: Dec 20, 1996

Geologist: B Nelson

Notes: The Beardmore-Geraldton Economic Geologist visited the minesite May 21, 1981, June 30, 1981, September 17, 1981, June 8, 1982, and September 21, 1983.

References

Article - 1982 report of the Thunder Bay Resident Geologist

Publication Number: MP107.004 Page: 67  Date: 1997

Author: Patterson G.C., Mason J.K., Schnieders B.R.

Publisher Name: Ontario Geological Survey

Location:

Map - O'Sullivan Lake area, District of Thunder Bay, Ontario

Publication Number: M1955-02 Scale: 1:12,000    Date: 1997

Author: Moorhouse W.W.

Publisher Name: Ontario Dept. of Mines

Location:

Part - Geology of the O'Sullivan Lake area

Publication Number: ARV64-04 Page: 23-36  Date: 1997

Author: Moorhouse W.W.

Publisher Name: Ontario Dept. of Mines

Location:

Article - 1981 report of the Thunder Bay Resident Geologist

Publication Number: MP101.004 Page: 61  Date: 1997

Author: McIlwaine W.H., Fenwick K.G., Scott J.F., Mason J.K., Schnieders B.R., Kristjansson F.J., Speed A.A., Bourdages H.M.

Publisher Name: Ontario Geological Survey

Location:

Map - Tashota-Geraldton sheet, geological compilation series, Thunder Bay and Cochrane districts

Publication Number: M2102 Date: 1997

Author: Pye E.G., Harris F.R., Fenwick K.G., Baillie J.

Publisher Name: Ontario Dept. of Mines

Location:

Compend - Report of activities, 1983, Regional and Resident Geologists

Publication Number: MP117 Page: 49, 87  Date: 1984

Author: Kustra C.R.

Publisher Name: Ontario Geological Survey

Location:

File - Resident Geologist Mineral Deposit Files

Publication Number: Min Dep Date: 1996

Author:

Publisher Name:

Location: Thunder Bay RGP

Folio - O'Sullivan Lake area, District of Thunder Bay

Publication Number: GDIF017 Date: 1997

Author: Thunder Bay RGO

Publisher Name: Ontario Geological Survey

Location:

Mono - Gold occurrences, prospects, and deposits of the Beardmore-Geraldton area, districts of Thunder Bay and Cochrane

Publication Number: OFR5630 Page: 152-161  Date: 1986

Author: Mason J.K., White G.D.

Publisher Name: Ontario Geological Survey

Location:

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For detailed information regarding this mineral record please contact the Thunder Bay North Resident Geologist District Office