Ontario Mineral Inventory

Ontario Geological Survey
Permanent Link to this Record: MDI52C09NE00019

Record: MDI52C09NE00019

General

Commodities

Primary Commodities: Silver

Secondary Commodities: Gold

Location

Township or Area: Factor Lake Area

Latitude: 48° 44' 33.54"    Longitude: -92° 8' 52.88"

UTM Zone: 15    Easting: 562636   Northing: 5399198    UTM Datum: NAD83

Resident Geologist District: Thunder Bay South

NTS Grid: 52C09NE

Point Location Description: Pit locations in Assessment report 20000013551

Location Method: Data Compilation

Exploration History

1993: D. Kroocmo carried out stripping. 1996: D. Kroocmo carried out prospecting, a beep mat survey, pitting, and sampling. 2012-18: D. Kroocmo carried out stripping and sampling.

Assessment Work on File

Geology

Province: Superior

Subprovince: Wabigoon

Geological Age: Archean  

Lithology

Lithology Comments

Sep 14, 2020 (Therese Pettigrew) - The Kroocmo Occurrence is located approximately 32 km west of Atikokan and 1 km north of Gehl Lake. Recent overburden stripping has exposed a highly deformed sequence of mafic to felsic metavolcanics which have been intruded by a series of small tonalite stocks. Detailed mapping has revealed that a large transported tectonic slice of Seine Series metasediments exists in fault contact with mafic metavolcanics. The Seine Series metasediments consist of intercalated polymictic conglomerate, arenite, wacke, slate, and minor chemical metasediments. They occur as a fault-bounded, technically transported alloch thon. Fumerton (1985) has recognized several other isolated fault-bound blocks of Seine Series metasediments which have been transported eastward from the Seine River wedge. The metavolcanics consist of a complex assemblage of mafic to felsic flows and tuffs which are intercalated with banded chemical metasediments. Compositionally the metavolcanics range from chlorite to sericite schist. Intense carbonatization is com mon and depends on the proximity to shear zones, hinge zones of folds, and tonalite stocks. The metavolcanics are folded isoclinally about an east-northeast-trending fold axis which plunges at a moderate angle to the west. Intruding the metavolcanics are a series of small tonalite stocks. The tonalite consists of fine-grained, whitish matrix containing small phenocrysts (less than 5 mm in diameter) of quartz and feldspar. Locally, the tonalite is brecciated and crosscut by a network of thin quartz-carbonate veins. The Quetico Fault, a major dextral tear fault, and several associated splay faults extend over the entire length of the property and separate rock units of contrasting structural styles. The fault zone ranges from 10 to 20 m in width and is typified by rocks which display a well-developed fabric striking 070 degrees with a near vertical dip. South of the fault, outcrops of isoclinally folded metavolcanics are observed; north of the fault, technically deformed Seine Series metasediments outcrops. As the fault zone is approached, biotite and carbonate alteration becomes pervasive (Patterson et al.,1987).

Mineralization

Mineralization Comments

Sep 14, 2020 (Therese Pettigrew) - Samples collected by prospector D. Kroocmo contain pyrite, chalcopyrite, and arsenopyrite (Assessment report 20000017016). No assays have been reported.

Mineral Record Details

References

Article - Thunder Bay Resident Geologist's area, North Central Region

Publication Number: MP134.004 Page: 119  Date: 1997

Author: Patterson G.C., Scott J.F., Mason J.K., Schnieders B.R., MacTavish A.D., Dutka R.J., Kennedy M.C., White G.D., Hinz P.

Publisher Name: Ontario Geological Survey

Location:

Report an Error

We are continuously updating our assessment file / technical report information. If you notice errors in the data, please contact us.

Terms of Use

Please review our Terms of Use agreement for this data product.

Ministry Contact Information

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