Ontario Mineral Inventory

Ontario Geological Survey
Permanent Link to this Record: MDI52G14NE00022

Record: MDI52G14NE00022

General

Commodities

Primary Commodities: Gold, Copper

Location

Township or Area: Penassi Lake Area

Latitude: 49° 58' 15.7"    Longitude: -91° 1' 46.7"

UTM Zone: 15    Easting: 641290   Northing: 5537270    UTM Datum: NAD83

Resident Geologist District: Kenora

NTS Grid: 52G14NE

Point Location Description: Sample 903515 from Assessment report 52G15NW2004

Location Method: Conversion from MDI

Access Description: The best access to the prospect is by the Cobb Bay Camp road which joins Hwy. 599 1 km south of the west end of Graystone Lake. The Cobb Bay road divides 600 m east of the highway. The south branch of the road, which is presently in poor repair, leads to a narrow north trending bay. The first trench is approximately 200 m south of the end of the road.

Exploration History

1970: Jorex Ltd. conducted EM and magnetic surveys. Pre-1974: unknown individuals carried out trenching. 1982: Corporation Falconbridge Copper carried out magnetic and EM surveys. 1989: JRJ Explorations staked the area and carried out a trenching and sampling program.1990: Gold Fields Canadian Mining Ltd, Noranda Exploration Company Ltd. and Asarco Exploration Co. of Canada Ltd. carried out prospecting and sampling. 1991: JRJ Explorations carried out prospecting, trenching, and sampling. 1994: JRJ Explorations carried out sampling and mapping. 2004: Unitronix Corp. carried out prospecting and sampling. 2005: Unitronix Corp. carried out prospecting and sampling. 2007: Unitronix carried out trenching, a magnetometer survey, and drilled 3 DDH totalling 473 m. 2008: 3936449 Canada Inc. carried out prospecting and sampling. 2010: 3936449 Canada Inc. carried out prospecting, sampling, and a soil gas hydrocarbon survey.

Assessment Work on File

Geology

Province: Superior

Subprovince: Wabigoon

Belt: Sturgeon Lake

Geological Age: Archean  

Geology Comments

Dec 07, 2005 (R Tuomi) - Trenching has exposed a 120 m intrusive contact between a 2 to 7 m wide north-trending quartz porphyry dike and sheared ankerite replaced massive metabasalt. Brown alteration surrounds the porphyry in a halo 1 to 3 m wide. Contacts of the halo with with metabasalt are relatively sharp. Commonly the altered portions of the metabasalt have thin, (3 to 6 mm), quartz veining with a strike of 220 degrees to 240 degrees. Two minor faults offset the dike on the north end of the outcrop. Sampling done in 1992 confirmed the assays for gold reported on the southern part of the trench in 1990 (Janes et al, 1993).

Lithology

Lithology Comments

Dec 07, 2005 (R Tuomi) - MINERALIZATION OCCURS IN: metabasalt with quartz vein stockwork HOST ROCK: mafic metavolcanics OTHER ASSOCIATED ROCK TYPES: 1) ankeritic metabasalt.

Feb 12, 2020 (Therese Pettigrew) - Trowell (1974) reports that there are two trenches (6 feet by 4 feet), approximately 700 feet apart, have been dug on this occurrence. The northernmost trench is in a sheared and carbonatized intermediate metavolcanic outcrop, which has a red-brown weathering surface; only minor pyrite mineralization was observed. The southern trench is in an outcrop of a silicified, intrusive(P) porphyritic rock; it is highly sheared (northeast trend) and carbonatized and minor pyrite and chalcopyrite mineralization was observed. Janes et al. (1993) describe the northern trench (JRJ’s A-zone) as a 3 to 7 m wide north-trending quartz porphyry dike and sheared ferrocarbonate altered massive metabasalt. The brown alteration surrounds the porphyry dike in a halo l to 3 m wide. Contacts of the halo with uncarbonated metabasalt are relatively sharp. Commonly the altered portions of the metabasalt has thin (3 to 6 mm), quartz veining with a strike of 220 to 240 degrees. Two minor faults offset the dike on the north end of the outcrop.

Mineralization

Mineralization Comments

Feb 12, 2020 (R Tuomi) - Samples taken by Ministry of Northern Development and Mines staff in 1990 ranged from 0.127 to 0.377 ounce gold per ton in chip and grab samples. Selected grab samples taken over the trench in 1992 ranged from 0.004 to 0.048 ounce gold per ton (Janes et al., 1993).

Feb 12, 2020 (Therese Pettigrew) - DDH Cobb 07-01 assayed up to 1711 ppb Au, 1087 ppb Au in hole Cobb 07-02, and 2462 ppb Au in Cobb 07-03 (Assessment report 20000002456). Sample 903515 assayed 7982 ppb Au (Assessment report 52G15NW2004). Samples collected in 1994 returned up to 1.30 oz/t Au from the A-zone (northern) and 1.22 oz/t Au from the B-zone (southern) (Assessment report 52G14NE0002). Sample DMH-05-02 returned 816 ppb Au and 256 ppm Cu from a rhyolite with a small quartz vein. Sample 910201 returned 3691 ppm Cu (Assessment report 20000001200). Samples collected in 2008 returned values up to 5635 ppb Au (Assessment report 20000004428).

Mineral Record Details

References

MonoMap - Geology of the Bell Lake-Sturgeon Lake area, districts of Kenora and Thunder Bay

Publication Number: R114 Page: 48  Date: 1974

Author: Trowell N.F.

Publisher Name: Ontario Division of Mines

Location:

Compend - Report of Activities 1992, Resident Geologists

Publication Number: MP161 Page: 71-73  Date: 1993

Author: Fenwick K.G., Pitts A.E., Newsome J.W.

Publisher Name: Ontario Geological Survey

Location:

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For detailed information regarding this mineral record please contact the Kenora Resident Geologist District Office