Ontario Geological Survey
Permanent Link to this Record:
MDI53B08NE00009
| Record Name(s) | Forester Lake - Fred's Zone - 1995 |
|---|---|
| Related Record Type | Simple |
| Related Record(s) | |
| Record Status | Occurrence |
| Date Created | 1995-May-23 |
| Date Last Modified | 2022-Jun-06 |
| Created By | |
| Revised By |
Primary Commodities: Copper, Gold
Township or Area: Forester Lake Area
Latitude: 52° 28' 49.21" Longitude: -90° 0' 46.21"
UTM Zone: 15 Easting: 702844.656 Northing: 5818660.429 UTM Datum: NAD83
Resident Geologist District: Thunder Bay North
NTS Grid: 53B08NE
Point Location Description: Precise
Location Method: Conversion from MDI
1987-88: Geological and geophysical surveys and diamond drilling by Esso Minerals of Canada.
| Office File Number | Online Assessment File Identifier | Online Assessment File Directory |
|---|---|---|
| 2.12011 | 53B08NE0001 | 53B08NE0001 |
| 53B08NE0010C1 | 53B08NE0015 | 53B08NE0015 |
Province: Superior
Subprovince: Berens River
Terrane: North Caribou
Domain: North Caribou Core
Belt: North Caribou
Geological Age: Mesoarchean
| Rock Type | Rank | Composition | Texture | Relationship | Ultramafic lava flow-unsubdivided | 1 | Epiclastic | Contains |
|---|---|---|---|---|
| Sandstone | 2 | Greywacke | Adjacent | |
| Gabbro | 3 | Adjacent | ||
| Felsic lava flow-unsubdivided | 4 | Fragmental | Near | |
| Ultramafic-Unsubdivided | 5 | Near | ||
| Mafic lava flow-unsubdivided | 6 | Near |
| Rank | Mineral Name | Class | Economic Mineral Type | Alteration Mineral Type | Alteration Ranking | Alteration Intensity | Alteration Style |
|---|---|---|---|---|---|---|---|
| 10 | Chalcopyrite | Economic | Ore | ||||
| 15 | Pyrite | Economic | Ore | ||||
| 20 | Pyrrhotite | Economic | Ore | ||||
| Biotite | Alteration | Biotitic | 1 | Unknown | Disseminated |
Mar 13, 2008 (Mark Puumala) - Hall (1987) indicated that this occurrence, which is exposed at surface and has been intersected by Esso Minerals Canada diamond drill hole FO88-10, is hosted in an ultramafic epiclastic unit comprised of polymictic angular fragments in a weakly- to well-bedded ultramafic matrix. Mapping by Hall (1987 and 1988) indicates that the rocks in the area of this occurrence, which has relatively few surface exposures, are dominated by gabbroic mafic metavolcanics. However, the results of diamond drilling suggest a relatively complex stratigraphy consisting of several rock types in the immediate area. Diamond drilling results from Esso Minerals Canada diamond drill holes FO88-10 (Hall 1988) indicate that the mineralized epiclastic horizon is bounded to the north by greywacke, and to the south by gabbro. Immediately to the south of drill hole FO88-10, drill hole FO88-11 encountered a thick sequence of intermediate to felsic fragmental metavolcanics that were reported to contain several massive pyrrhotite horizons (Hall 1988). An ultramafic intrusion has also been documented to the west of the occurrence by Hall (1988) in diamond drill hole FO88-9. Mapping by Hall (1988) indicates that stratigraphy and foliation in the area of this occurrence strike northwest with moderate to steep southwesterly dip. Hall (1987) initially interpreted the epiclastic unit to have been folded into a tight southeast-plunging antiform. However, this interpretation was not supported by the results of diamond drilling, which suggest a north-facing homoclinal sequence (Hall 1988). The epiclastic rocks in the vicinity of this occurrence are reported by Hall (1987) to have been affected by a later tectonic event that has folded them about an east-northeast-trending axis. This folding event has resulted in the development of 45 to 70 degree southwest-plunging folds with an axial planar cleavage that is very strongly developed in clast-rich beds. Many of these cleavage planes are also reported to exhibit evidence of sinistral shearing. The gold mineralization at this location is reported by Hall (1987) to be associated with narrow quartz veinlets and disseminated sulphide mineralization (average of 3% pyrrhotite and 1% chalcopyrite) that parallel the east-northeast-striking cleavage planes. The most notable assays from the surface expression of this showing include 2000 ppb Au and 1.49% Cu from a grab sample reported by Breaks, Osmani and DeKemp (1987). Diamond drill hole FO88-10, which was advanced through the epiclastic horizon approximately 200 m southeast of the surface showing was reported to have assayed 1667 ppb Au over 2.21 m in sulphide-rich (12% pyrrhotite and 3% pyrite), ultramafic matrix epiclastic breccia (Hall 1988).
| Rank | Classification |
|---|---|
| 1 | Lode (Gold) |
| Rank | Characteristic |
|---|---|
| 1 | Sheared |
Map - Geological series, Precambrian geology, Opapimiskan-Neawagank lakes area, eastern part, (Opapimiskan Lake project), Kenora District (Patricia Portion)
Publication Number: P3081 Scale: 1:31,680 Date: 1987
Author: Breaks F.W., Osmani I.A., de Kemp E.A., Fogal R.I., Cortis A.L., Woytiuk K., Arias Z.G.
Publisher Name: Ontario Geological Survey
Location:
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