Ontario Mineral Inventory

Ontario Geological Survey
Permanent Link to this Record: MDI42D15SW00051

Record: MDI42D15SW00051

General

Commodities

Primary Commodities: Zinc, Copper, Sulphur/Pyrite

Location

Township or Area: Tuuri

Latitude: 48° 46' 41.09"    Longitude: -86° 52' 6.56"

UTM Zone: 16    Easting: 509661.68   Northing: 5402794.76    UTM Datum: NAD83

Resident Geologist District: Thunder Bay South

NTS Grid: 42D15SW

Point Location Description: Trench

Location Method: Field Visit

Access Description: The Little Steel Lake Highway occurrences are located on Highway 17 about 1.2 km east of the Steel River bridge which is approximately 16 km directly east of Terrace Bay in Tuuri Township. Access may be gained from Highway 17.

Exploration History

1951: Sulphide mineralization discovered; G. Simard and P. Swetz. 1952: Trenching; G. Simard and P. Swetz. 1960-1976: The occurrence was staked several times by various parties but no work was recorded. 1977: Geophysical survey (EM) and 1 DDH totalling 50.3 m; HBOG Mining Limited. 1983: Geophysical survey (MAG, EM); L. Salo and D. McKinnon (?). 1984: Trenching, sampling and test pitting; Silver Sceptre Mines Ltd. 1994: Prospecting and sampling; B. Fowler, M. Shuman and D. Leishman. 1995: Prospecting, reconnaissance geological mapping and lithogeochemical sampling; Echo Bay Mines. 2002: D. Courtney conducted geological mapping, prospecting, and sampling.

Assessment Work on File

Geology

Province: Superior

Subprovince: Wawa

Terrane: Wawa-Abitibi

Belt: Schreiber-Hemlo

Geological Age: Archean  

Geology Comments

Dec 07, 2005 (D McKay) - The geology consists of intercalated metavolcanics and metasediments. The metasediments consist of graded turbidites with beds up to 25 cm wide. Schnieders (1987) described a sedimentary succession dominated by A- and AB-turbidites, organized into upward (southward) coarsening and thickening, and fining and thinning sequences. These assemblages were thought to represent deposition on suprafan lobes and submarine channels, respectively. The metavolcanics appear to be of intermediate to mafic composition, and possibly amygdaloidal and variolitic. In addition Smyk and Schnieders (1995) have identified spinifex-textured, basltic-komatiite in the Steel River area. A sulphide iron formation is present which parallels the stratigraphy. Other rock types include lamprophyre and diabase dikes. Schnieders (1987), Williams (1989) and Smyk and Schnieders (1995) have suggested complex folding events, accompanied by large scale faulting in the Steel River area. The Steel River area has undergone two periods of folding, however, the F2 event or second folding event produced a well-defined, axial planar cleavage. The fold axis of the F2 event has a trend of approximately 60 and a plunge of 50-60 . Examination of the Little Steel Lake occurrences and the neighbouring Simard-Swetz occurrence was completed by Ontario Ministry of Northern Development and Mines personnel. Both occurrences consist of interbedded chemical sediments and exhalative ironstone. Banded or bedded chert was observed, with recrystallized chert containing pyrite and pyrrhotite. Galena and zinc mineralization is associated with quartz-carbonate veinlets within chemical and clastic metasedimentary rocks at the Simard-Swetz occurrence.

Lithology

Lithology Comments

Jul 16, 2018 (D McKay) - Schnieders (1987) described the Little Steel Highway occurrence as two northeast striking, chert or siliceous schist units less than 50 cm thick occurring along a sedimentary-volcanic contact where a mafic dike has also been emplaced. The two highway occurrences are separated by approximately 100 m. At the Little Steel East Highway occurrence pyrrhotite is hosted by chloritic schist and brecciated chert, and is intruded by a metagabbroic dike. The dike contains fragments of the sulphide-facies iron formation and contact metamorphism has probably affected the primary sulphide assemblage, leading to an increase in the proportion of pyrrhotite (Schnieders, 1987). A texture similar to 'Durchbewegung' was observed in the pyrrhotite at this location (Schnieders 1987). Schnieders (1987) describes the Little Steel railway occurrence as an extension of the highway occurrence, however, more brecciated chert and mafic dikes are present. Minor sphalerite is present at this occurrence associated with a laminated chert.

Mineralization

Mineralization Comments

Jul 16, 2018 (D McKay) - Walker (1967, p.35) notes the presence of galena, sphalerite, pyrrhotite and pyrite in graphitic schist, as well as mentioning the reported values of silver and gold said to have been retrieved. Rose (1951, assessment files) notes that: The graphitic schists contain narrow bands of pyrite 0.16 cm (? inch) wide or less, and nodules of pyrite. The estimated pyrite content of the graphitic schist was usually less than 10% and was never more than 50%. Minor amounts of chalcopyrite occurred as scattered grains in quartzite (recrystallized? chert) near the middle of the east boundary of claim TB 42606. A Northern Miner article (May 3, 1984) states: The principal minerals in order of magnitude are: chert (chalcedony), massive and nodular pyrite, massive and stringer pyrrhotite, irregular narrow quartz-calcite veins, graphite and trace amounts of chalcopyrite, sphalerite and galena. Grab samples collected from the occurrences in 1984 by OGS Resident Geologist staff returned assay values which varied from <2 to 26 ppb Au, <2 to 3.5 ppm Ag, 54 to 1290 ppm Cu, <10 to 505 ppm Pb and 62 to 1620 ppm Zn.

Jul 16, 2018 (Therese Pettigrew) - The best assays from HBOG’s 1977 DDH S-TP-77-1 were 0.05% Cu and 0.37% Zn (AFRI 42D15SW0094)

Mineral Record Details

References

File - Schreiber-Hemlo Resident Geologist Mineral Deposit Files

Publication Number: Min Dep Date: 1996

Author:

Publisher Name:

Location: Thunder Bay RGP

Map - Nipigon-Schreiber, geological compilation series, Thunder Bay District

Publication Number: M2232 Scale: 1:253,440    Date: 1973

Author: Carter M.W., McIlwaine W.H., Wisbey P.A.

Publisher Name: Ontario Division of Mines

Location:

Mono - Mineral Occurrences in the Nipigon-Marathon Area, Volumes 1 and 2.

Publication Number: OFR5951 Page: 662-668  Date: 1996

Author: Schnieders B.R., Smyk M.C., Speed A.A., McKay D.B.

Publisher Name: Ontario Geological Survey

Location:

Map - Jackfish-Middleton area, Thunder Bay District

Publication Number: M2107 Date: 1967

Author: Walker J.W.R.

Publisher Name: Ontario Dept. of Mines

Location:

MonoMap - Geology of the Jackfish-Middleton area, District of Thunder Bay

Publication Number: R050 Date: 1997

Author: Walker J.W.R.

Publisher Name: Ontario Dept. of Mines

Location:

Thesis - Geology of Sulphide-Facies Iron Formations and Associated Rocks in the Lower Steel River - Little Steel Lake Area, Terrace Bay, Ontario Area

Publication Number: MSc thesis Date: 1987

Author: Schnieders, B.R.

Publisher Name: Lakehead University

Location: Thunder Bay RGP

Book - GEOLOGY OF THE SCHREIBER GREENSTONE ASSEMBLAGE, ILSG GUIDEBOOK, V.41, PT.2C

Publication Number: Guide Book Date: 1995

Author: Smyk, M.C. and Schnieders, B.R.

Publisher Name:

Location: Thunder Bay RGP

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