Ontario Mineral Inventory

Ontario Geological Survey
Permanent Link to this Record: MDI52B14NW00004

Record: MDI52B14NW00004

General

Commodities

Primary Commodities: Gold

Secondary Commodities: Copper, Silver

Location

Township or Area: Sawbill Bay Area

Latitude: 48° 57' 1.7"    Longitude: -91° 25' 59.33"

UTM Zone: 15    Easting: 614715.27   Northing: 5423133.08    UTM Datum: NAD83

Resident Geologist District: Thunder Bay South

NTS Grid: 52B14NW

Point Location Description: Old mine site

Location Method: Conversion from MDI

Access Description: Access is via Steep Rock Iron Mines Limited roads. One exists between Finlayson and Marmion Lakes and terminated at the Seine River Diversion approximately 9.25km southwest of Sawbill Lake Mine. The other road, west of Finlayson Lake, terminates at the mouth of the Sawbill Creek as it enters Sawbill Bay, approximately 4km north-northeast of the mine site.

Exploration History

1895: Discovered by the Wiley Brothers. 1896: Sawbill Lake Gold Mining Company Ltd. is incorporated. Main shaft was sunk to 44.2m, with underground drifting and cross cutting. 1897: The shaft was deepened to 62.6m, with underground drifting and cross cutting. An air shaft was sunk 56.7m south of the main shaft on the same vein. A tramway was built some 168m to the mill. 1898: The shaft was deepened to 70 m and the underground workings were expanded. 1899: The shaft was deepened to 74.7m and the underground workings were expanded. All mining operations ceased in fall of 1899. 1937: Upper Seine Gold Mines Ltd. was formed and assumed ownership of the property. 1938: Underground workings were expanded, until June when work ceased and the shaft was allowed to fill with water. 1939: Work resumed but the mine was not dewatered. 180 m of trenching was conducted. 1940: Mine dewatered. Underground work continued. 50 Ton amalgamation mill erected. 1941: Underground work until Sept 24, 1941 when the mine and mill were shut down. 1984: Falconbridge Ltd. conducted an airborne EM, magnetometer and VLF-EM survey. 1987-88: Falconbridge drilled 8 DDH totalling 1399.5 m. 1994-96: Kinross acquired the property via the Kinross and Falconbridge Gold Corporation amalgamation. Pentland Firth Ventures Ltd. (PFV) obtained an option to acquire the property from Kinross. PFV conducted prospecting, trenching, sampling and linecutting. 1997: PFV conducted trenching, sampling, prospecting, and drilled 16 DDH totalling 3640.8 m. 2006-9: Brett Resources acquired the property conducted geological mapping, prospecting, sampling, soil sampling, trenching, a magnetometer survey, and drilled 135 DDH. 2010: Osisko Mining acquired Brett Resources and began a large definition drill program. 2011: Osisko Hammond Reef Gold Ltd. conducted a helicopter-towed aeromagnetic gradient survey.

Assessment Work on File

Geology

Province: Superior

Subprovince: Wabigoon

Geological Age: Archean  

Lithology

Mineralization

Mineralization Comments

Apr 28, 2016 (Therese Pettigrew) - The gold mineralization at Hammond Reef occurs within a 2.5 km segment of a broad anastomosing corridor of sericite-ankerite-chlorite alteration and associated gold enrichment, extending from the Steep Rock assemblage, 15 km SW, to the Lumby Lake Greenstone Belt, 15 km NE. Gold mineralization at Hammond Reef is found in all lithological phases of the Marmion batholith. Mineralization is associated with fracture-controlled quartz vein stockwork and minor pyrite (generally < 1%) in variably altered granitoid rocks and mafic dykes within and adjacent to a foliated schists and fault zones. Gold is hosted within all lithologies exhibiting concentrations of brittle, micro- to macro-fractures. Petrographic studies indicate that gold grains tend to be preferentially sited on pyrite aggregate grain boundaries, healed fractures or inclusions. Rare visible gold also occurs as free grains on sericitic foliation planes within the highly altered granitoid (AFRO 2.52163). The presence of a grey metallic mineral as local grey stains and smears in, especially, leader veins, is thought to be an excellent indicator of the presence of gold. A Scanning Electron Microprobe (SEM) of a small portion of this material by the OGS (M. Smyk, Ref. No. 96-BBN-01) identified a bismuth telluride, possibly comprising tellurobismuthite (Bi2Te3) and tetradymite (Bi2Te2S) (AFRO 2.44214).

Mineral Record Details

References

MonoMap - Geology of the Finlayson Lake area, District of Rainy River

Publication Number: R145 Page: 48-52  Date: 1976

Author: Fenwick K.G.

Publisher Name: Ontario Division of Mines

Location:

Mono - Feasibility of small scale gold mining in northwestern Ontario (parts of the districts of Kenora, Rainy River, and Thunder Bay), volume 1, text, volume 2, appendices

Publication Number: OFR5332 Page: 56-57  Date: 1981

Author: Neilson J.N., Bray R.C.E.

Publisher Name: Ontario Geological Survey

Location:

Mono - Gold deposits of the Atikokan area

Publication Number: MDC024 Page: 28-30  Date: 1982

Author: Wilkinson S.

Publisher Name: Ontario Geological Survey

Location:

Mono - Property visits and reports of the Atikokan economic geologist, 1979-1983, Atikokan geological survey

Publication Number: OFR5539 Page: 433-439  Date: 1985

Author: Schnieders B.R., Dutka R.J.

Publisher Name: Ontario Geological Survey

Location:

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