Ontario Mineral Inventory

Ontario Geological Survey
Permanent Link to this Record: MDI52F04NE00012

Record: MDI52F04NE00012

General

Commodities

Primary Commodities: Gold

Secondary Commodities: Silver

Location

Township or Area: Brooks Lake Area

Latitude: 49° 12' 43.49"    Longitude: -93° 44' 20.59"

UTM Zone: 15    Easting: 446174   Northing: 5451295    UTM Datum: NAD83

Resident Geologist District: Kenora

NTS Grid: 52F04NE

Point Location Description: Map in AFRI 52F04NE0012

Location Method: Conversion from MDI

Exploration History

1944: Gold was discovered on the west end of East Island by Noranda prospectors. Trenching and sampling was conducted. 1974: the property was optioned by Roy Martin to a joint venture consisting of Noranda, Newcnex, and Tombill Mines. The JV conducted geological mapping. 1975: the joint venture conducted geological surveys and drilled 7 DDH totalling 614.5 m (6 of the holes on the East Island showings). 1983: Barrier Reef Resources drilled 7 DDH totalling 1181.7 m across Hay Island, East Island, and the intervening lake bottom. A lake bottom survey was carried out to detail the topography and recover lake sediment samples. 1986: Laramide Resources Ltd. conducted trenching and sampling. 1987: Laramide conducted magnetometer, VLF-EM, and IP surveys. 1990: Rio Algom and Laramide Resources drilled 1 DDH totalling 310 m.

Assessment Work on File

Geology

Province: Superior

Subprovince: Wabigoon

Geological Age: Archean  

Lithology

Lithology Comments

Oct 27, 2017 (Therese Pettigrew) - Associated with the shear zone and gold showings are a series of felsic, quartz, and feldspar porphyry sills. They appear intermittently along the shear zone and are metamorphosed to about the same degree as their volcanic host rocks (AFRI 52F04NE0012).

Mineralization

Mineralization Comments

Oct 27, 2017 (C Ravnaas) - Grab samples from west end of island returned up 0.62 oz/T Au quoted from Kenora Assessment File 52F04NE O-2.

Oct 27, 2017 (Therese Pettigrew) - Three trenches from 1944 were reported as follows: Trench No. 1: 0.30 opt Au over 11.5 ft; Trench No. 2: 0.16 opt Au over 14 ft; Trench No. 3: 0.15 opt Au over 18 ft. Mapping by the OGS has outlined a strong zone of shearing and deformation extending from Hay Island, through East Island to the mainland, a distance of about 3 miles. The two presently known gold showings are located in this zone of deformation (AFRI 52F04NE0012). DDH MC 75-3 intersected the zone 70 ft west of the No. 1 trench and 200 ft below the surface. The zone yielded 0.33 opt Au over 5 ft. A zone of pyrite mineralization is located beneath the western end of East Island. Pyrite occurs in the tuffaceous matrix of slightly siliceous intermediate to felsic lapilli tuffs in the form of medium to coarse grains 1 to 3 mm in diameter, and as very finely disseminated grains. The pyrite comprises from 5 to 20% of the rock and averages 10%. Concentrations of pyrite are found along the outer boundaries of lapilli fragments and as isolated aggregates. The fragments contain little or no pyrite. The pyrite-rich zone extends for at least 240 feet near surface on the west end of East Island. The zone strikes 080 and dips 80 to 85 to the north. The gold-bearing zone lies within the pyrite-rich zone and has a strike length of 150 ft, terminating at the end of the island and pinching out to the east along with the pyrite-rich zone. Partial alteration of the rocks occurs in the form of seritization, carbonatization, and minor silicification and chloritization. Sericitization is the most common occurring as films of sericitic minerals along foliation planes and paper-thin sericitic partings parallel to the local foliation. Narrow quartz and quartz-carbonate veins occur at random intersecting all rock types. They average 1 to 4cm in width and exhibit no preferred orientation. Carbonate content varies from trace amounts to 30%. The veins are typically barren of sulfides. Locally, inclusions of country rock within the veins carry minor pyrite. Barrier Reef’s 1982-83 drill program outlined a more or less continuous zone with an average true thickness of 100 feet (30.5 m) and an average gold concentration of 300 ppb along a strike length of 6500 ft (1981.2 m). The gold-bearing unit is a near vertical bed of felsic to rhyolitic lapilli tuff containing up to 2% banded and disseminated pyrite (AFRI 52F04NE0031). Edwards (1980) collected 5 chip samples from Trench #2. The samples returned assays ranging from trace up to 0.47 opt Au and 0.22 opt Ag.

Mineral Record Details

References

Map - Schistose Lake, Kenora District

Publication Number: M2421 Scale: 1:31,680    Date: 1980

Author: Edwards G.R.

Publisher Name: Ontario Geological Survey

Location:

MonoMap - Geology of the Schistose Lake area, District of Kenora

Publication Number: R194 Scale:     Date: 1980

Author: Edwards G.R.

Publisher Name: Ontario Geological Survey

Location:

Mono - Gold deposits of the Kenora-Fort Frances area, districts of Kenora and Rainy River

Publication Number: MDC016 Scale:     Date: 1976

Author: Beard R.C., Garratt G.L.

Publisher Name: Ontario Division of Mines

Location:

Mono - Geology of the Pipestone Lake [north] area, District of Kenora

Publication Number: OFR5194 Scale:     Date: 1976

Author: Edwards G.R.

Publisher Name: Ontario Division of Mines

Location:

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