Ontario Geological Survey
Permanent Link to this Record:
MDI52F07SW00028
| Record Name(s) | Beaverhead Island - 1984 |
|---|---|
| Related Record Type | Simple |
| Related Record(s) | |
| Record Status | Occurrence |
| Date Created | 1991-Mar-24 |
| Date Last Modified | 2022-Jul-07 |
| Created By | |
| Revised By |
Primary Commodities: Gold
Township or Area: Lower Manitou Lake Area
Latitude: 49° 16' 40.67" Longitude: -92° 53' 56.47"
UTM Zone: 15 Easting: 507344.743 Northing: 5458361.351 UTM Datum: NAD83
Resident Geologist District: Kenora
NTS Grid: 52F07SW
Point Location Description: General
Location Method: Conversion from MDI
Access Description: The Beaverhead Island claims are situated in the Manitou Lakes area, Kenora Mining Division, Ontario, and occupy portions of claim map-areas G-2683 (Lower Manitou Lake), G-2572 (Boyer Lake), and G-2584 (Harper Lake) in N.T.S. map-area 52-F-7. Winter access into the area from Highway 502 is via a 5 km long skidoo trail into the settlement of Gold Rock. The trail leaves Highway #502 approximately 50 km south of Dryden, Ontario. Summer access is via float plane or by boat from Cedar Narrows, approximately 80 km to the south. The skidoo trail into Gold Rock is passable using ATC's but is not suitable for hauling boats. (Assessment File 52F07SW X-4, Cochrane Oil and Gas Ltd, Kenora Resident Geologist Office)
1983: Cochrane Oil and Gas carried out small reconnaissance geophysical, geological, and geochemical surveys and drilled 1520’ using Winkie drills. 1984-85: Cochrane Oil and Gas carried out ground magnetic and VLF-EM surveys, geological mapping, sampling.
| Office File Number | Online Assessment File Identifier | Online Assessment File Directory |
|---|---|---|
| 2.8195 / 52F07SW X-4 | 52F07NE8318 | 52F07NE8318 |
Province: Superior
Subprovince: Wabigoon
Terrane: Western Wabigoon
Belt: Eagle-Wabigoon-Manitou
Geological Age: Precambrian
Feb 23, 2010 (D Scholtz) - During the period December 10, 1984 to March 29, 1985, a total of approximately 270 line kilometres of ground CEM, VLF-EM, and magnetic surveying was carried out over a 10m by 25m grid. Cross lines and base lines were slashed, blazed, chained, and flagged at 25m intervals. CEM and VLF-EM readings were taken at 25m intervals; magnetometer readings were taken at 12.5m intervals. Geological mapping of Map Sheets 1, 2, 3, 7, 8 and 9 was carried out under winter field conditions. Map Sheets 4, 5 and 6 were subsequently mapped under summer field conditions. Approximately 700 rock samples were collected and geochemically analyzed for Au. This work was performed by personnel of Cordilleran Resource Management Ltd. of Calgary, Alberta. Previous work by Cochrane Oil and Gas consisted of a number of small reconnaissance geophysical, geological, and geochemical surveys at various points within the present survey area, plus a number of Winkie drill holes at widespread locations within the present survey area. None of the reconnaissance grids exceeded a total of 2.5 line km. The total footage of the Winkie drill holes was 1,520'. The most significant results of this drilling were the intersection of a massive sulphides zone at the west end of Mosher Bay, and an intersection running up to 0.7 oz/ton gold in a hole at the south end of Leuiller Island. Archean volcanic and sedimentary stratigraphy in the Manitou Lakes area is typical of the greenstone belts of Wabigoon Sub-province. In broad terms, a lower mafic volcanic unit is succeeded by a sequence of intermediate to felsic flows and related tuffs, which is in turn overlain by a package of clastic and chemical metasediments consisting of conglomerate, sandstone, siltstone-argillite, chert, and derived schists. In some areas there is evidence of a younger mafic volcanic unit capping the metasediments. These 'upper' mafic volcanics are probably related to numerous late stage gabbroic intrusions which occur as small stocks and elongated dykes or sills. These rocks have been folded, faulted, and metamorphosed to green schist facies metamorphic grade, and are preserved in a northeasterly to easterly trending synclinorium herein referred to as the Manitou Lakes Synclinorium. This volcanic 'trough' is bounded on the southeast by the Irene-Eltrut Lakes batholithic complex and on the northwest by the Atikwa batholithic complex. Felsic metavolcanics and metasediments occur along the core of the synclinorium and are flanked by broad belts of mafic volcanics. Major schist zones related to folding and faulting parallel the trend of the synclinorium. These zones of weakness have been the focus of late stage (Kenoran) felsic dyking, further transcurrent faulting, and have acted as conduits for hydrothermal fluids which have produced intense hydrothermal alteration. Gold deposits in the Manitou lakes area are closely related to these major structures. The schist zones may be the result of penetrative deformation fabrics along major isoclinal (?) fold axes and/or may have been produced by transcurrent and vertical movements along a "mobile" zone separating the major crustal blocks represented by the Atikwa and Irene-Eltrut lakes batholithic complexes.
Feb 23, 2010 (C Ravnaas) - The Beaverhead Island area (within this survey area) is underlain on the southeast by a thick sequence of volcanic clastic and polymictic conglomerate beds. Overlying the conglomerates is a 50m to 100m thick sandstone unit which fines upwards, through a series of siltstone and argillite interbeds, into a banded iron formation containing interlaminated oxide (magnetite) and sulphide (pyrite) facies. This entire metasedimentary section dips southeasterly but is overturned and "up-section" i s to the northwest. The metasedimentary package comprises the overturned southeasterly limb of a northeasterly trending synclinal fold and is truncated, along and parallel to the banded iron formation, by a major schist zone (Manitou Straits Fault) which has been developed along the axis of the syncline. To the northwest, the banded iron formation is in contact with intermediate and mafic metavolcanics which in part also exhibit a strong axial planar(?) penetrative deformation fabric. Flow tops (determined in pillowed lavas) indicate that these rocks are not overturned and constitute the northwesterly, upthrown(?) limb of the syncline from which the sedimentary package has been removed. Across the width of the schist zone, numerous quartz-carbonate-pyrite alteration lenses and quartz-pyrite stringers, veinlets, and lenses have developed. Highly anomalous Au-in-rock geochemical values ranging up to 1,000+ ppb occur across a 50m wide carbonatized and sericitized section of the schist zone on the southern tip of Beaverhead Island. A strongly sheared silicate-carbonate facies iron formation may constitute part of the alteration. One hundred metres to the southeast, a subparallel, less well exposed zone of strong shearing and quartz-carbonate-sulphide mineralization some 25m to 40m in width also carries anomalous Au-in-rock values. These two zones exhibit many similarities to the environments hosting the ore horizons both at Hemlo and Joutel (Agnico Eagle Mine). Surface sampling to date is of a semi-reconnaissance nature; surface stripping and trenching will be required for a proper evaluation.
| Rank | Mineral Name | Class | Economic Mineral Type | Alteration Mineral Type | Alteration Ranking | Alteration Intensity | Alteration Style |
|---|---|---|---|---|---|---|---|
| 5 | Pyrite | Economic | Ore |
Feb 23, 2010 (C Ravnaas) - At Beaverhead Island highly anomalous Au-in-rock values ranging up to 1,000+ ppb have been obtained across a 50 m wide section of one of the very strongly sheared zones of carbonatized and sericitized pyritic metasediments present at the southern end of the island. The carbonatized quartz-sericite and sericitic schists appear to include boudined lenses of carbonate-silicate facies iron formation. A geological environment bearing many similarities to the Hemlo and Joutel (Quebec) districts is indicated. A second subparallel zone of carbonatized metasediments, some 100m to the southeast also carries anomalous Au-in-rock values and similarly warrants stripping, trenching and systematic channel sampling. (Assessment File 52F07SW X-4, Cochrane Oil and Gas Ltd, Kenora Resident Geologist Office)
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