Ontario Mineral Inventory

Ontario Geological Survey
Permanent Link to this Record: MDI42D16SW00016

Record: MDI42D16SW00016

General

Commodities

Primary Commodities: Gold, Copper, Platinum, Palladium, Nickel

Secondary Commodities: Cobalt, Rhodium, Titanium, Silver, Iron

Location

Township or Area: O'Neill

Latitude: 48° 46' 56.24"    Longitude: -86° 19' 24.36"

UTM Zone: 16    Easting: 549701   Northing: 5403475    UTM Datum: NAD83

Resident Geologist District: Thunder Bay South

NTS Grid: 42D16SW

Point Location Description: Precise

Location Method: Conversion from MDI

Access Description: The Marathon property is located on the north shore of Lake Superior approximately 290 km east of Thunder Bay, Ontario and 12 km from the town of Marathon. The Marathon claim group is accessible from Highway 17 by a gravel road, the last 4.8 km of which was constructed by Anaconda.

Exploration History

1962: Anaconda Company (Canada) Ltd. conducted geological mapping and trenching. 1963: Anaconda conducted an IP survey. 1964-7: Anaconda drilled 171 DDH totalling 36,537m and conducted airborne and ground mag surveys. 1964: Anaconda took a small bulk sample (5200 lb). 1966: Anaconda took a 150 ton sample. 1974-76: various studies were conducted. 1976: claims were converted to leases. 1982: Anaconda relogged 10 historic drill holes and reevaluated the property. 1984: Fleck Resources Ltd. purchased the property from Anaconda. 1985-86: Fleck resampled historic core, re-established the grid, drilled 37 DDH totalling 3852 m, trenched and sampled. 1986: Fleck blasted 40 tons of mineralized representative material (10 tons from 4 pits) and sent it for testing, and conducted geological mapping. 2000: property was staked by M. and S. Stares. 2000-01: Freewest Resources Canada Inc. optioned the property and conducted an airborne magnetometer and TEM survey. 2003: Marathon PGM Corp. acquired the property. 2004: Marathon PGM drilled 1 DDH. 2005-06: Marathon PGM conducted prospecting, sampling, geological mapping, trenching, and drilled 22 DDH totalling 4028.4 m. 2007-08: Marathon PGM conducted geological mapping and drilled 226 DDH totaling 46,166 m including 36 DDH totaling 2401.25 m on the American Brass showing. 2011: Stillwater acquired the leases.

Assessment Work on File

Geology

Province: Superior

Subprovince: Wawa

Terrane: Wawa-Abitibi

Geological Age: Archean  

Geology Comments

Sep 29, 2015 (Therese Pettigrew) - The area is predominantly underlain by gabbro belonging to the Port Coldwell alkalic complex. To the east, the gabbro intrudes rocks belonging to an older metavolcanic-metasedimentary assemblage. Numerous, eastward-dipping dikes of larvikite syenite and younger, lamprophyre dikes intrude the gabbro (Shklanka, 1969).

Lithology

Lithology Comments

Sep 29, 2015 (Therese Pettigrew) - The margin of the Coldwell Complex is composed of two gabbroic phases: an early (olivine gabbro) phase, and a later olivine-biotite gabbro. The later gabbro is discontinuous along the marginal contact, dips moderately westwards, and locally contains disseminated chalcopyrite and pyrrhotite with variable concentrations of Platinum Group Elements. The intrusive rocks of the Coldwell Alkalic Complex consist of an olivine gabbro outer zone and a syenitic core. The mineralized part of the complex is contained within the outer zone olivine gabbro. There, olivine gabbro was intruded by an olivine-biotite gabbro containing sulfide mineralization. This later intrusion is focused along the Complex/metavolcanic contact where it has almost completely displaced the earlier olivine gabbro towards the core of the Complex. The olivine-biotite gabbro intruded parallel to or slightly obliquely to the igneous layering exhibited in the early gabbro. Lateral continuity of this unit ranges from 500 m to 10 km. thickness is on the order of 20 to 100 m. The abundance of olivine-biotite gabbro decreases rapidly up-section, where it becomes a series of thin and discontinuous lenses with minor sulfide mineralization. The Two Duck Lake Gabbro, which contains the Cu-Ni-PGE mineralization, ranges from medium through coarse and very coarse-grained to pegmatitic. The medium-grained unit varies from olivine-biotite to olivine-biotite-hornblende gabbro in composition. Olivine and biotite contents range from 2 to 10 ft. Coarse-grained olivine-biotite gabbro (7c) represents the bulk of the Two Duck Lake intrusion. Olivine content ranges from 1 to 5% and biotite ranges from 5 to 15%. The very coarse-grained olivine-biotite gabbro contains olivine and biotite contents similar to the coarse- grained gabbro but may contain up to 15% Fe-Ti oxides (ferro-gabbro). Pegmatitic, olivine-biotite or olivine-hornblende-biotite gabbro, which may contain variable Fe-Ti oxides (up to 10%), is a volumetrically small unit. This unit is extremely discontinuous and has patchy crosscutting and oblique lenses-like forms (AFRI 42D16SE0021).

Mineralization

Mineralization Comments

Dec 06, 2018 (Therese Pettigrew) - Sulphide mineralization is scattered throughout the banded gabbro unit but becomes significantly concentrated in some widely separated localities. Higher copper values are about 0.5 percent (Milne, 1967). Pyrrhotite, pyrite and chalcopyrite occur as interstitial fillings, and are associated with the coarser grained, ilmenomagnetite-rich phase of the Two Duck Lake gabbro. Assays indicate a variation in copper from 0.05% to about 2% (Shklanka, 1969). The sulfide mineralized zone lies close to the marginal contact of the Complex and the highly deformed metavolcanics. Sulfide content is variable, generally pyrrhotite-rich and chalcopyrite-poor. Massive sulfides, up to 0.5 m thick, may occur in this unit near the basal contact. Sulfides; chalcopyrite, pyrrhotite, and voilarite, occur mostly as interstitial composite grains. Biotite and Fe-Ti oxides may be closely associated with sulfides, especially where sulfide patches or clots occur; such as in very coarse and pegmatitic material. Apatite is often present in the coarse to pegmatitic material (with or without sulfides). Platinum Group Elements (PGE) occur as discrete Platinum Group Minerals (PGM) in and attached to the sulfides and/or Fe-Ti oxides. Platinum, palladium, and minor rhodium occur. The Pd/Pt is approximately 6/1 (AFRI 42D16SE0021). The highest Cu assay from the 2007-8 drill program was 0.504% Cu from DDH M-07-296. The highest Ni assay from the 2007-8 drill program was 689 ppm Ni from DDH M-07-291. The highest Pd and Pt assays from the 2007-8 drill program were 1707 ppb Pt and 3064 ppb Pd from DDH M-07-296 (Assessment file 20000013681).

Mineral Record Details

References

Book - Northern Miner 86-03-17 Fleck p. 12

Publication Number: NMINER Date: 1996

Author:

Publisher Name: Northern Miner

Location:

MonoMap - Geology of Cirrus Lake-Bamoos Lake area, District of Thunder Bay

Publication Number: R043 Page: 43  Date: 1997

Author: Milne V.G.

Publisher Name: Ontario Dept. of Mines

Location:

Mono - Copper, nickel, lead and zinc deposits of Ontario

Publication Number: MDC012 Page: 303  Date: 1969

Author: Shklanka R.

Publisher Name: Ontario Dept. of Mines

Location:

Map - Bamoos Lake sheet, Thunder Bay District

Publication Number: M2099 Date: 1997

Author: Milne V.G.

Publisher Name: Ontario Dept. of Mines

Location:

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:

Map - Precambrian Geology, Port Coldwell Complex, East Half

Publication Number: P3233 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