Ontario Mineral Inventory

Ontario Geological Survey
Permanent Link to this Record: MDI52B14NW00003

Record: MDI52B14NW00003

General

Commodities

Primary Commodities: Gold

Secondary Commodities: Copper, Lead, Silver

Location

Township or Area: Sawbill Bay Area

Latitude: 48° 56' .68"    Longitude: -91° 28' 9.06"

UTM Zone: 15    Easting: 612115   Northing: 5421195    UTM Datum: NAD83

Resident Geologist District: Thunder Bay South

NTS Grid: 52B14NW

Point Location Description: Small shaft and many trenches

Location Method: Data Compilation

Access Description: The old Hammond Reef Mine is situated on the east shore of the upper part of Sawbill Bay in Marmion Lake. It is 1.2 km southwest of Sawbill Lake Mine and approx. 24.5 km northeast of Atikokan, Ontario. From Atikokan, the Hammond Reef Gold Property is accessible by road via the paved Ontario Secondary Highway 622 for 26 km northwest to the intersection with the Hardtack-Sawbill Road, then northeast approximately 24 kilometres along this gravel road to the Hammond Reef Camp, at the northern end of Marmion Reservoir, Sawbill Bay area.

Exploration History

1895: Discovery by J. Mistahasen. 1896: J. Hammond and H. Folger acquired the property and commenced exploration and development work with subsequent shafts, drifts and crosscuts. 1897: An open cut 90 m long and 6 m deep was excavated. On the south side of this a large trench 29.6 m long, 12 m wide and 11.6 m deep was dug. A test shaft was sunk to a depth of 24 m. At 18 m depth, a drift was driven east for 6 m and west for 5.1 m. Assays were reported to be considerably higher at the bottom of this shaft than on the surface. Much trenching was done, an open cut 14.3 m long, 2.7 m wide and 3.6 m deep was excavated. A tramway 1/3 mile long connected the open cut with a 10 stamp mill constructed in October. A shorter tramway led from the inclined shaft to the main tramway. 1898: The work was confined to the open pits. Underground work was abandoned. New open pit 18 m long 6 m wide and 3 to 6 m deep. An open cut 24 m long, 7.6 m wide and 4.6 m deep. Ore zone found to be too narrow to work. 1899: Hydro electric power plant built by damming a small creek near the property. Increased the mill to 40 stamps. Limited amount of trenching and stripping was done on the property. 1900: The new mill was damaged by an electrical storm. 18 m shaft sunk from bottom of quarry. 3 exploratory adits driven from 15 to 30 m and all had low results. Operations were suspended due to lower than expected grades. 1928: Copper Zinc Mines of Sudbury Ltd. acquired the property. Unknown amount of work was done, claims were brought to patent. Report by M. B. Glazier. 1931: Detailed sampling by Noranda Mines Ltd. 1932: Report by Rossmore Mines, numerous veins reported. Property renamed to Rossmore Mine. 1944: Frobisher Exploration Co. Ltd. acquired the property from Copper Zinc Mines and sampling was conducted. 1960: Venture Claims Ltd. acquired the property from Frobisher. 1962: Falconbridge Nickel Mines Ltd. absorbs Ventures Claims Ltd. 1979: Property visited by Ontario Geological Survey Gold Deposit Study. 1984-88: Additional claims acquired by Falconbridge. Extensive exploration program of line cutting, geological mapping, soil geochemistry, magnetometer, IP and VLF geophysical surveys, trenching, channel sampling, leach testing and 21 DDH totalling 4061 m. 1989-90: Falconbridge drilled 46 DDH totalling 10,359 m and calculated a resource. 1994-96: Pentaland Firth Ventures optioned the property from Kinross, who had acquired the property when Kinross and Falconbridge merged. An exploration program comprised of prospecting, grab sampling, line cutting, and limited trenching was completed. 1997: Pentland Firth drilled 16 DDH totalling 3640.8 m. Extensive trenching and channel sampling was undertaken on the main Hammond Reef property, with detailed prospecting on adjacent properties. A resource estimate was released. 2006: Brett Resources optioned the property from Kinross. 2006-09: Brett drilled 138 DDH totalling 31,429 m and released an NI 43-101 compliant resource estimate in 2009. 2010: Osisko Hammond Reef Gold Ltd. made a successful takeover bid for Brett Resources and acquired the property. Osisko completed a geological mapping program and a helicopter-borne magnetic survey. From 2006-2011, Brett and Osisko drilled a total of 1266 exploration holes totalling 405,678.19 m and 22 condemnation holes totalling 3318.0 m. 2011: Osisko released an NI 43-101 resource estimate. 2013: Osisko suspended construction of the mine due to low gold prices and high construction costs. 2014: Yamana Gold Inc. and Agnico Eagle Mines Ltd. bought out Osisko in June. Yamana and Agnico each own 50% of the Hammond Reef deposit.

Assessment Work on File

Geology

Province: Superior

Subprovince: Wabigoon

Geological Age: Archean   Geochronological Age: 2999-3001 Ma   Geochron. Age Ref.: Stone and Davis, OGS OFR6192, 2006

Geology Comments

Mar 23, 2015 (Therese Pettigrew) - The Hammond Reef Gold Property is located in the southern portion of the Central Wabigoon Subprovince within the Archean Superior Province. The property is situated near the western contact of the Marmion Batholith with the Finlayson Greenstone Belt. The Finlayson rocks, mainly metavolcanics with minor metasediments, form a relatively narrow belt of rock characterized by ductile deformation, entrained between and partially overlying the Marmion Batholith to the east and the Eye-Dashwa Batholith to the west. The greenstone belt extends around the southwest point of the Marmion Lake Batholith, terminating at the Quetico Fault. Along its south edge, the Marmion Terrane, comprising volcano-sedimentary rocks interpreted to represent a rift margin, is in fault contact with the Quetico Sediments along the eastern extension of the Quetico Fault.

Lithology

Lithology Comments

Mar 23, 2015 (Therese Pettigrew) - Most of the peninsula between Sawbill and Lynxhead Bays, hosting the A Zone, 41 Zone and the RAB Zone is underlain by tonalite. The most prominent structural features in the A Zone are the NE-SW trending Upper and the Lower Shears (thrust zones), roughly bounding the altered granitoid zone, and the majority of the zone’s mineralization; the Lower Shear terminates in the transition between the A and the 41 Zone and the interpreted extension of the Upper Shear in the 41 Zone is the dominant structural feature, with mineralization enveloping the shear above and below. Additional zones of intense shearing appear intermittently within the altered granitoid. Quartz leader veins and stockwork are ubiquitous as is ankerite veining. Notable is the splay of altered granitoid extending southwards to Lynxhead Bay through the RAB Zone (with several off-shoots of the splay semi-parallel to the main A-41 Zone structure). Splays trending EW and NS extend from the eastern end of the 41 Zone (41 Extension Zone, more precisely), through the Upper Seine Zone, and then northwards to the Snail Bay Zone (Cukor et al, 2011).

Mineralization

Mineralization Comments

Mar 23, 2015 (Therese Pettigrew) - The Hammond Reef Gold Deposit is described as a high-tonnage/low-grade shear-hosted gold deposit. Gold is hosted within any lithology (except gneiss) exhibiting an appropriate concentration of brittle micro- to macrofractures. While the presence of stockwork and leader veins does not always guarantee significant values, gold content of these drill core sections and surface channel assays is generally consistent with areas of >0.4 g/t Au. A continuous, one to six kilometre wide corridor of anastomosing zones of sericite alteration and associated gold enrichment has been defined within the Marmion Lake batholith. Quartz is the most common vein-filling mineral, followed by lesser percentages of chlorite, calcite, sericite, and less than 1% pyrite, occasionally accompanied by trace galena, chalcopyrite, sphalerite, pyrrhotite, bornite, chalcocite, or native gold. Various researchers have also noted the presence of tellurite, stromeyerite, and molybdenite. Anomalous gold mineralization at Hammond Reef is found in all lithological phases, except gneiss. Examples of >0.4 g/t Au drill intersections and channel samples from granitoid, mafic dyke, pegmatite and quartz vein are ubiquitous. Victorian workings were confined to leader veins, where grades of >5 g/t Au were mined. Examples of >0.4 g/t Au drill intersections and channel samples from granitoid, mafic dyke, pegmatite and quartz vein are ubiquitous. Victorian workings were confined to leader veins, where grades of >5 g/t Au were mined. There are 3 types of mineralization across the deposit: Type 1: structurally confined mineralization: between A Zone and Mitta Zone where the gold mineralization and strong to moderate, pervasive alteration are confined between two shear zones; Type 2: gold mineralization occurs in partially altered tonalite. Alteration is patchy or spotty, leaving about 50% of the tonalite unaltered; Type 3: mineralization in “unaltered” rocks, where gold mineralization is hosted in what has been logged as unaltered tonalites. A closer look shows that these auriferous green tonalites are altered by a chlorite/carbonate alteration accompanied by pyrite. In turn, the pyrite is associated with fractures, veinlets and veins filled with various combinations of chlorite, calcite and quartz. The pyrite is either in the fractures, veinlets or veins, usually with the chlorite or in the vein wall rock over a few cms on either side of the features. If pyrite is absent from the assemblage, usually no gold values are observed (Cukor et al, 2011).

Mineral Record Details

References

Map - Finlayson Lake area (east half), District of Rainy River

Publication Number: P0543 Scale: 1:15,840    Date: 1997

Author: Fenwick K.G.

Publisher Name: Ontario Dept. of Mines

Location:

Map - Marmion Lake, Rainy River District

Publication Number: M2298 Scale: 1:31,680    Date: 1976

Author: Fenwick K.G.

Publisher Name: Ontario Division of Mines

Location:

Map - Precambrian Geology, Sapawe Area

Publication Number: P3350 Scale: 1:50,000    Date: 1995

Author: Stone D., Pufahl P., Carter J.

Publisher Name: Ontario Geological Survey

Location:

Publication - Preliminary Assessment of the Hammond Reef Gold Property; Atikokan, Ontario, Canada; NI 43-101 Report

Publication Number: 2009 43-101 Date: 2009

Author:

Publisher Name: Scott Wilson Roscoe Postle Associates Inc.

Location:

Publication - Technical Report on the Hammond Reef Gold Property; Atikokan Area, Ontario

Publication Number: 2011 43-101 Date: 2011

Author: Cukor, D., Gignac, L-P, Dagbert, M.

Publisher Name: SGS Canada Inc.

Location: SEDAR

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

Publication Number: R145 Page: 56-57  Date: 1976

Author: Fenwick K.G.

Publisher Name: Ontario Division of Mines

Location:

Mono - Gold deposits of the Atikokan area

Publication Number: MDC024 Page: 30-33  Date: 1982

Author: Wilkinson S.

Publisher Name: Ontario Geological Survey

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

Publication Number: OFR5539 Page: 226-234  Date: 1985

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

Publisher Name: Ontario Geological Survey

Location:

Mono - Report of Activities 2012, Resident Geologist Program, Thunder Bay South Regional Resident Geologist Report: Thunder Bay South District

Publication Number: OFR6285 Date: 2013

Author: Puumala M.A., Campbell D.A., Cundari R.M., Zurevinski S.E., Tuomi R.D., Lockwood H.C., Debicki R.L., Moses P., Brunelle M.R., Pelaia R.

Publisher Name: Ontario Geological Survey

Location:

Map - Precambrian Geology Compilation Series - Quetico Sheet

Publication Number: M2663 Scale: 1:250,000    Date: 2001

Author: Santaguida F.

Publisher Name: Ontario Geological Survey

Location:

Map - Atikokan-Lakehead sheet, geological compilation series, Kenora, Rainy River and Thunder Bay districts

Publication Number: M2065 Scale: 1:253,440    Date: 1997

Author: Pye E.G., Fenwick K.G.

Publisher Name: Ontario Dept. of Mines

Location:

Map - Geology and Tectonostratigraphic Assemblages, South-Central Wabigoon Subprovince, Ontario

Publication Number: P3448 Scale: 1:250,000    Date: 2002

Author: Stone D., Tomlinson K.Y., Davis D.W., Fralick P.W., Hallé J., Percival J.A., Pufahl P.

Publisher Name: Ontario Geological Survey

Location:

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