Ontario Mineral Inventory

Ontario Geological Survey
Permanent Link to this Record: MDI42D16SW00015

Record: MDI42D16SW00015

General

Commodities

Primary Commodities: Copper

Secondary Commodities: Palladium, Platinum, Silver, Gold, Iron

Location

Township or Area: Seeley Lake Area

Latitude: 48° 52' 2.78"    Longitude: -86° 29' 3.46"

UTM Zone: 16    Easting: 537820   Northing: 5412848.01    UTM Datum: NAD83

Resident Geologist District: Thunder Bay South

NTS Grid: 42D16NW, 42D16SW

Point Location Description: Trench O from AFRI 20000001915

Location Method: Data Compilation

Access Description: Accessible by helicopter from the Marathon airport, or by the Mink Trail, 18 km west of Marathon, off Highway 17.

Exploration History

1914-19: Copper and nickel were discovered by prospectors. Seemar Mines Ltd. carried out trenching and blasting. 1954: Caral Mining Company conducted prospecting, ground magnetometer, SP and resistivity surveys, mapping, and drilled 2 DDH totalling 343 m. 1959-64: Head of the Lakes Iron Ltd. carried out ground magnetometer, HLEM and VLEM and self potential surveys, airborne EM surveys, geological mapping and drilled 21 DDH. 1962: Denison Mines acquired an interest in the property. 1964: Head of the Lakes Iron was renamed to Lakehead Mines Ltd. and carried out mapping and drilled 108 DDH totalling 6791 m. 1976: D. Fairbairn flew an airborne radiometric and EM survey. 1980: Parlake Resources was created after a merger of Lakehead Mines Ltd. with other companies. 1990: property was sold to Redstone Resources Ltd., who carried out prospecting, soil geochemistry surveys, geophysics, and drilled 4 DDH totalling 443 m. 2005: Benton Resources acquired the property from Redstone. 2006: Benton Resources carried out trenching and sampling. 2007: Benton Resources drilled 11 DDH totalling 1995.65 m. 2008: Benton Resources drilled 11 DDH totalling 2369 m. 2013: Stillwater Canada Inc. drilled 31 DDH totalling 6690 m. 2017: Stillwater was acquired by Sibanye Gold Ltd. and renamed to Sibayne-Stillwater, who drilled 16 DDH. 2019: Generation Mining Ltd. acquired a 51% interest in the property and released a resource estimate.

Assessment Work on File

Geology

Province: Superior

Subprovince: Wawa

Terrane: Wawa-Abitibi

Geological Age: Archean  

Geology Comments

Oct 30, 2015 (Therese Pettigrew) - Area 41 is located along the NE margin of the Coldwell Complex, which was emplaced into Archean age felsic to mafic metavolcanic, clastic metasedimentary and granite intrusive rocks. The Coldwell complex is part of the Keweenawan group igneous rocks that were emplaced along the Midcontinent Rift System, a triple junction located in the Nipigon area of the Superior Province. The Coldwell Complex is composed of six major lithologies that have been grouped into three intrusive centers. The general stratigraphy of the intrusion consists of Archean footwall rocks to the east, intruded by Center I, and III of the Coldwell Alkaline Complex. Footwall xenoliths of mafic to felsic metavolcanic and clastic metasedimentary rocks have been observed in Center I rocks. 1) Center I includes the 700-2000 m thick Eastern Border Gabbro which has been intruded by augite/olivine-augite syenite, intruded again by amphibole syenite. 2) Center II is composed of massive alkalic (Ca-rich) gabbro and a layered nepheline syenite. 3) Center III is composed of barkevikite syenite, quartz syenite and granite. The Coldwell Complex Center unit has been intruded along the north, north-eastern and eastern contact by the Four Dams Lake Gabbro on the northern and north-eastern contact and the Two Duck Lake gabbro on the eastern contact (AFRI 20000001915).

Lithology

Lithology Comments

Oct 30, 2015 (Therese Pettigrew) - The Bermuda Property is underlain by Center I rocks bound to the northeast by metavolcanic, metasedimentary and granitic rocks. Archean mafic to felsic metavolcanic and meta-sedimentary rocks are characterized by fine grain to aphanitic, commonly chlorite altered mafic phases, light grey felsic volcanic, banded tuff and pyrite bearing meta-sedimentary (quartzite) units. Granite to tonalite intrusive rocks border the northeastern corner of the property. Proterozoic Eastern Border Gabbro (EBG) is a fine-grained, massive, equigranular light to medium grey weak to moderately magnetic unit. It is composed of plagioclase feldspar, amphiboles, pyroxenes and olivine. Accessory phases include magnetite, apatite and quartz. Favourable PGE mineralization is found hosted in the basal sequence as contact style mineralization associated with large xenoliths (AFRI 20000001915).

Mineralization

Mineralization Comments

Dec 17, 2019 (Therese Pettigrew) - The majority of Cu-PGE mineralization in surface sample is characterized by 1-3% (up to 5%) disseminated to net textured chalcopyrite + pyrrhotite as primary sulphide phases. Petrographic analyses from the Marathon Deposit indicate bornite + pentlandite + marcasite + pyrite are common accessory sulphide phases. Oxide cumulate layers commonly host elevated palladium and local Cu values. The oxide cumulate layers are common in, but not restricted to, the upper portions of the intrusive. Two styles of mineralization are commonly observed along the Proterozoic/Archean contact and include: 1) Contact-style pods and lenses of disseminated sulphides at or near the contact with the 2) reef-style oxide cumulate layers that host decreased Cu tenor but considerable PGE mineralization. Trench O had the following assay highlights from the 2006 trenching campaign: 85.93 ppb Au, 288.01 ppb Pt, 714.4 ppb Pd, 0.17% Cu, and 0.01% Ni over 68 m including 262 ppb Au, 1357 ppb Pt, 3989 ppb Pd, 0.31% Cu, and 0.01% Ni over 1 m; 355 ppb Au, 1073 ppb Pt, 3877 ppb Pd, 0.43% Cu, and 0.02% Ni over 1 m; 64.7 pb Au, 639.07 ppb Pt, 1274.43 ppb Pd, 0.11% Cu and 0.01% Ni over 7 m; 115 ppb Au, 1434 ppb Pt, 3874 ppb Pd, 0.15% Cu and 0.01% Ni over 1 m (AFRI 20000001915). Significant assays from the 2013 drilling program included 0.10-0.46% Cu, 0.02-0.75 ppm Pt, and 0.01-1.51 ppm Pd (AFRO 2.55704). Drilling in the Sally Area 41 occurrence has intersected 4 mineralized zones, referred to in descending order from top to bottom, as Zones 1 to 4. Zone 1: The uppermost mineralized zone contains Cu and trace amounts of Pd, and is commonly less than 10 metres thick. Zone 1 is hosted by Two Duck Lake Gabbro that is intermixed with Marathon Series oxide melatroctolite. Zone 2: The second mineralized zone is hosted by Two Duck Lake Gabbro that generally includes xenoliths of the Fine Grained Gabbro Series. This second mineralized zone is typically 40 to 50 m thick and contains some of the highest Pd grades in the deposit, particularly at the contact between the Marathon Series (Breccia unit A) and the feldspathic clinopyroxenite unit of the Fine-Grained Series. Zone 3: occurs below the feldspathic clinopyroxenite unit and is referred to as the Main zone because it is normally over 40 m thick and is the most continuous over the strike length of the deposit, except at the far west end where mineralization is cut by multiple faults. The mineralization is hosted by Two Duck Lake Gabbro. Zone 4: occurs below the main mineralized zone, where Fine Grained Series and/or Archean footwall are crosscut by Marathon Series intrusions. Mineralisation contains Cu and Pd values that are similar to the main zone, but has increased pyrrhotite content, and thus is considered to be lower tenor (Puritch et al., 2019).

Mineral Record Details

References

Map - Manitouwadge sheet, districts of Thunder Bay and Algoma, geological compilation series

Publication Number: P0494 Scale: 1:126,720    Date: 1997

Author: Milne V.G.

Publisher Name: Ontario Dept. of Mines

Location:

Publication - Technical Report, Updated Mineral Resource Estimate of the Marathon Deposit

Publication Number: 2019 NI 43-101 Date: 2019

Author: Puritch, E., Brown, F., Feasby, D.G., Pitman, P., Barry, J., Mackie, B.

Publisher Name: P&E Mining for Generation Mining

Location: SEDAR

Map - Precambrian Geology, Port Coldwell Complex, West Half

Publication Number: P3232 Scale: 1:20,000    Date: 1993

Author: Walker E.C., Sutcliffe R.H., Shaw C.S.J., Shore G.T., Penczak R.S.

Publisher Name: Ontario Geological Survey

Location:

Map - Port Coldwell area, District of Thunder Bay

Publication Number: P0114 Scale: 1:31,680    Date: 1997

Author: Puskas F.P.

Publisher Name: Ontario Dept. of Mines

Location:

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