Ontario Mineral Inventory

Ontario Geological Survey
Permanent Link to this Record: MDI42D14SE00071

Record: MDI42D14SE00071

General

Commodities

Primary Commodities: Gold

Location

Township or Area: Priske

Latitude: 48° 50' 34.63"    Longitude: -87° 14' 10.21"

UTM Zone: 16    Easting: 482671.66   Northing: 5410024.77    UTM Datum: NAD83

Resident Geologist District: Thunder Bay South

NTS Grid: 42D14SE

Point Location Description: Stripped areas

Location Method: Other Literature

Access Description: The Twomey B.I.F. occurrence is located approximately 6 km northeast of Schreiber in Priske Township. Access is by 4x4 via the old Cook Lake road to Big Duck Creek, at which point the old road can be followed on foot or by all-terrain vehicle. The occurrence is located approximately 400 m east of Big Duck Creek.

Exploration History

1991: T. Twomey discovered the occurrence while prospecting in the Schreiber area. The prospecting program was assisted by an OPAP grant. 1992: Stripping, geological mapping, sampling, and VLF and magnetic ground surveys were conducted with the assistance of an OPAP grant. 1995: The property was optioned by RJK Explorations. 2001: S. Kravchik carried out prospecting.

Assessment Work on File

Geology

Province: Superior

Subprovince: Wawa

Terrane: Wawa-Abitibi

Belt: Schreiber-Hemlo

Geological Age: Archean  

Geology Comments

Dec 07, 2005 (B Nelson) - The area is underlain by mafic metavolcanic rocks, mainly pillowed and massive flows. Oxide and sulphide facies iron formation is intercalated within the metavolcanic rocks. Minor metasedimentary rocks are also present. Gabbro is also present. Schnieders et al. (1993) describes the Twomey B.I.F as: Oxide facies formation consisting of laminated magnetite and chert bands (locally jasper) is observed in several locations throughout the property. The iron formation at location #1 is hosted by fine grained, pelitic, metasedimentary rocks (DE turbidites) or mudstone, as well as greywacke and minor conglomerate. The iron formation is 3 to 4 m in width and strikes 290 degrees to 320 degrees and dips 55 degreesNE. Mafic intrusive rocks, mainly gabbro, intrude the metasedimentary rocks. Gold mineralization is associated with secondary sulphides in crosscutting fractures within the iron formation, as well as sulphide replacements of the chert and magnetite layers. Semi massive pyrite is present over widths of up to 5 cm in association with the cross fractures and replaced layers. Pyrite preferentially replaces the chert layers in a 'brickwork' type fashion. The cross fractures strike 100 degrees and are commonly associated with areas of jaspilitic iron formation. Approximately 400 m east of location #1 a second iron formation was discovered and stripped by T. Twomey. At this site, the iron formation is bedded at 300/ 60 NE. Several narrow iron formations hosted by metasedimentary and metavolcanic rocks make up a unit 2 to 30 m wide. Magnetite rich layers up to 15 cm thick are interlaminated with chert layers. At location #2, sulphide replacement is evident; pyrite preferentially replaces the magnetite layers. Here the chert layers are less affected. Pyrite occurs as a stratabound, replacement feature. The northern part of the outcrop could be arguably classified as sulphide facies iron formation.

Lithology

Mineralization

Mineralization Comments

Dec 07, 2005 (B Nelson) - Grab sample 92 BTT 1 collected by Resident Geologist staff consisted of pyrite rich (less than or equal to 20%) iron formation and assayed 0.156 ounces Au per ton. Sample 92 BTT 3 assayed 0.014 ounces Au per ton, 3320 ppm Zn and 424 ppm Cu indicating elevated base metal values. Pyrite also occurs in several small crosscutting fractures. A grab sample (92 BTT 04) returned 0.02 ounces Au per ton. While conducting the property visit, several additional iron formation exposures were observed, some previously stripped by Corporation Falconbridge Copper and others requiring further sampling and exploration for both gold and base metals. This suggests a number of parallel iron formations with potential strike lengths up to 3 km.

Mineral Record Details

Site Visit Information

Date: Feb 20, 1997

Geologist: B Nelson

Notes: Resident Geologist personnel visited the occurrence August 5, 1992.

References

File - Schreiber-Hemlo Resident Geologist Mineral Deposit Files, Thunder Bay office

Publication Number: Min Dep Date:

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: 453-455  Date: 1996

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

Publisher Name: Ontario Geological Survey

Location:

Map - Schreiber area, District of Thunder Bay, Ontario

Publication Number: ARM47J Scale: 1:31,680    Date: 1997

Author: Bartley M.W., Harcourt G.A.

Publisher Name: Ontario Dept. of Mines

Location:

Map - Geological series, Precambrian geology of the Terrace Bay area, west sheet, Thunder Bay District

Publication Number: P2417 Scale: 1:15,840    Date: 1981

Author: Carter M.W.

Publisher Name: Ontario Geological Survey

Location:

Compend - Report of Activities 1992, Resident Geologists

Publication Number: MP161 Page: 131-132  Date: 1993

Author: Fenwick K.G., Pitts A.E., Newsome J.W.

Publisher Name: Ontario Geological Survey

Location:

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Ministry Contact Information

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