Ontario Geological Survey
Permanent Link to this Record:
MDI000000000234
| Record Name(s) | Gunnar Berg Occurrence - 1946 |
|---|---|
| Related Record Type | |
| Related Record(s) | |
| Record Status | Occurrence |
| Date Created | 2007-Feb-06 |
| Date Last Modified | 2022-Jun-09 |
| Created By | |
| Revised By |
Primary Commodities: Gold, Copper
Township or Area: Kapkichi Lake Area
Latitude: 51° 28' 44.46" Longitude: -90° 19' 42.92"
UTM Zone: 15 Easting: 685500 Northing: 5706480 UTM Datum: NAD83
Resident Geologist District: Thunder Bay North
NTS Grid: 52O08NW
Point Location Description: Assessment file maps and location descriptions.
Location Method: Data Compilation
1928: Gold mineralized vein discovered on south shore of Kapkichi Lake by Gunnar Berg 1946 - 50: Trenching, ground magnetic survey and diamond drilling by Central Patricia Gold Mines. 1987-1988: Geological and geophysical surveys and diamond drilling by Umex.
| Office File Number | Online Assessment File Identifier | Online Assessment File Directory |
|---|---|---|
| 52O09SE0036A1 | 52O09SE0141 | 52O09SE0141 |
| 52O08NW0021 | 52O08NW0030 | 52O08NW0030 |
| 2.12157 | 52O08NW0004 | 52O08NW0004 |
Province: Superior
Subprovince: Uchi
Terrane: North Caribou
Domain: Uchi
Belt: Pickle Lake
Geological Age: Mesoarchean
Feb 06, 2007 (Mark Puumala) - The most prominent structural feature identified in the Kapkichi Lake area is a shear/mylonite zone having an approximate orientation of 240/50 (Patterson and Watkinson (1984). Several northeast-striking faults oriented approximately 030/50 have been mapped in the Kapkichi Lake area by Patterson (1980), while a set of northwest-striking faults (separated by 200-300 m) exhibiting sinistral displacements of 50 to 100 m have also been mapped to the southeast of Kapkichi Lake by Mullen (1987). Cameron (1980) has interpreted structural features in the nearby Thierry Mine area as representing four separate episodes of deformation. The first deformation event (D1) is represented by compositional layering (S1) within the amphibole schist that forms the hanging wall and footwall of the ore deposit. This deformation event is interpreted to have transposed compositional layering to an orientation approximately parallel to foliation. The S1 fabric is also indicated by Cameron (1980) to be oriented approximately parallel to the Thierry ore body, which is reported to have an orientation that ranges between 240-250/45-55. The second deformation event (D2) is interpreted by Cameron (1980) to have resulted in the development of folds with an axial planar cleavage (S2) having an orientation ranging from approximately 251/54 in the hanging wall amphibolite schist and 248/46 in the footwall amphibolite schist. Patterson (1980) interpreted the presence of an axial planar fabric oriented approximately 248/68 based on structural measurements taken at locations away from the mine site. The fold axes are reported by Cameron (1980) to be approximately parallel to a well-developed mineral lineation in the amphibolite schist. The orientation of this lineation is reported by Cameron (1980) to vary significantly between the hanging wall and footwall amphibolite schist, with reported average orientations of 358/47 and 293/36. This discrepancy is interpreted to have been caused during a later rotational deformation event. Patterson (1980) also suggests the presence of a broad bend in the orientation of the axial planes of D2 folds. Mullen (1987) reports a synformal fold in the vicinity of Wimbabika Lake whose axis plunges to the northeast at approximately 40 degrees (i.e., similar to observations at Thierry). A third deformation event (D3) is represented by kink bands that affect the S2 fabric (Cameron 1980). The final interpreted (D4) deformation event is reported by Cameron (1980) to be represented by splay faults in the Thierry ore body and the rotation of the S2 fabric described above.
| Rock Type | Rank | Composition | Texture | Relationship | Vein | 1 | Host |
|---|---|---|---|---|
| Mafic lava flow-unsubdivided | 2 | Adjacent |
Feb 06, 2007 (Mark Puumala) - The Kapkichi Lake-Wimbabika Lake area is underlain by a narrow northeast-southwest trending belt of metavolcanic rocks consisting predominantly of amphibolitized mafic metavolcanic rocks (see Map P.3056). Mullen (1987) reports that diamond drill core, geophysical survey data, and outcrop exposures in the vicinity of Wimbabika Lake indicate that the mafic metavolcanics contain a number of horizons of banded chert-magnetite iron formation and thin layers of felsic schist (tuff). In the vicinity of Kapkichi Lake, the supracrustal rocks have been intruded by a series of tabular mafic to ultramafic intrusions consisting of gabbro, peridotite and dunite. These intrusions host copper-nickel-PGE mineralization, with the most notable example being the Thierry Mine deposit. Stott (1996) suggests that these mafic to ultramafic intrusions are likely to be synvolcanic sills. Numerous felsic dikes and sills have also been noted to intrude the supracrustal rocks of this area by Mullen (1987). The supracrustal rocks of this area are wedged between granitic rocks of the Williams Lake Batholith to the north and the Pickle Lake Stock to the south (Stott 1996). The mafic metavolcanic-dominated supracrustal rock sequence of this area has been classified by Young (2003) as being part of the >2860 Ma Pickle Crow Assemblage.
| Rank | Mineral Name | Class | Economic Mineral Type | Alteration Mineral Type | Alteration Ranking | Alteration Intensity | Alteration Style |
|---|---|---|---|---|---|---|---|
| 1 | Chalcopyrite | Economic | Ore |
Feb 06, 2007 (Mark Puumala) - The Gunnar Berg gold occurrence is described by Thomson (1946) as consisting of two small gold-bearing quartz veins with intervening ladder veinlets exposed on the south shore of Kapkichi Lake on Claim Pa 7788 or 7789. Lytle (1949) later indicates the presence of a vein mineralized vein drilled by Central Patricia Mines on claim 7789. The veins are reported by Thomson (1946) to strike northeast, with the southernmost vein dipping to the southeast. Subsequent drilling by Central Patricia Gold Mines in 1946 reportedly encountered significant chalcopyrite mineralization (up to 2% Cu), but little gold. However, one assay of 0.45 oz/ton Au was reported from this drilling program (Thomson 1946).
| Rank | Classification |
|---|---|
| 1 | Lode (Gold) |
| Rank | Characteristic |
|---|---|
| 1 | Vein |
Thesis - Structural Analysis of the Thierry Copper-Nickel Deposit in Northwest Ontario, Canada.
Publication Number: MSc thesis Date: 1980
Author: Cameron, P.J.
Publisher Name: Pennsylvania State University
Location: Thunder Bay RGP
Thesis - The Geology of the Kapkichi Lake Ultramafic-Mafic Bodies and Related Cu-Ni Mineralization, Pickle Lake, Ontario
Publication Number: PhD thesis Date: 1980
Author: Patterson, G.C.
Publisher Name: Carleton University
Location: Thunder Bay RGP
Journal - The Geology of the Thierry Cu-Ni Mine, Northwestern Ontario
Publication Number: Can Min Vol 22 Page: 3-11 Date: 1984
Author: Patterson, G.C. and Watkinson, D.H.
Publisher Name: Canadian Mineralogist
Location: Thunder Bay RGP
Mono - The Geology and Tectonic History of the Central Uchi Subprovince
Publication Number: OFR5952 Date: 1996
Author: Stott G.M.
Publisher Name: Ontario Geological Survey
Location:
Thesis - New Structural, Geochronological, and Geochemical Constraints on the Tectonic Assembly of the Archean Pickle Lake Greenstone Belt, Uchi Subprovince, Western Superior Province
Publication Number: MSc thesis Date: 2003
Author: Young, M.D.
Publisher Name: Queen's University
Location: Thunder Bay RGP
We are continuously updating our assessment file / technical report information. If you notice errors in the data, please contact us.
Please review our Terms of Use agreement for this data product.
For detailed information regarding this mineral record please contact the Thunder Bay North Resident Geologist District Office