Ontario Geological Survey
Permanent Link to this Record:
MDI000000002667
| Record Name(s) | Castor Lake - 1950, Active Zone - 1985 |
|---|---|
| Related Record Type | |
| Related Record(s) | |
| Record Status | Occurrence |
| Date Created | 2021-Oct-29 |
| Date Last Modified | 2022-Jan-18 |
| Created By | |
| Revised By |
Primary Commodities: Gold
Township or Area: Seeseep Lake Area
Latitude: 52° 58' 37.92" Longitude: -90° 58' 23.8"
UTM Zone: 15 Easting: 636078 Northing: 5871656 UTM Datum: NAD83
Resident Geologist District: Thunder Bay North
NTS Grid: 53B15NW
Point Location Description: DDH C-85-1 from Assessment report 53B15NW0018
Location Method: Data Compilation
Circa 1950s: trenching was carried out by unknown individuals. 1985: Northern Dynasty Exploration Ltd. carried out ground magnetometer, EM, and soil surveys, rock sampling, mapping, and drilled 3 DDH totalling 449.6 m as operator for the Ontario Gold Joint Venture. 1987: Ontario Gold Joint Venture carried out ground magnetics and EM surveys, soil sampling and geological mapping.
| Office File Number | Online Assessment File Identifier | Online Assessment File Directory |
|---|---|---|
| 53B15NW0011A1 | 53B15NW0018 | 53B15NW0018 |
| 53B15NW0012D1 | 53B15NW0023 | 53B15NW0023 |
| 53B15NW0019 | 53B15NW0020 | 53B15NW0020 |
| 2.10629 | 53B15NW0013 | 53B15NW0013 |
Province: Superior
Subprovince: Berens River
Terrane: North Caribou
Domain: North Caribou Core
Belt: North Caribou
Geological Age: Archean
| Rock Type | Rank | Composition | Texture | Relationship | Ironstone-unsubdivided | 1 | quartzite-grunerite | Host |
|---|---|---|---|---|
| Schist-Unsubdivided | 2 | chlorite-silica-garnet | Near |
| Rank | Mineral Name | Class | Economic Mineral Type | Alteration Mineral Type | Alteration Ranking | Alteration Intensity | Alteration Style |
|---|---|---|---|---|---|---|---|
| 1 | Arsenopyrite | Economic | Ore | ||||
| 2 | Pyrrhotite | Economic | Ore | ||||
| 3 | Pyrite | Economic | Ore | ||||
| 1 | Mariposite | Economic | Gangue | ||||
| 2 | Fuchsite | Economic | Gangue |
Oct 29, 2021 (Therese Pettigrew) - The principal mineralization and the main exploration target is the gold-arsenopyrite zone at the west end of Castor Lake. Massive banded to disseminated arsenopyrite with significant associated gold values occur in a grunerite iron formation horizon. A channel sample across the mineralization returned as assay of 1.95 g/t gold over a true width of 1.9 m. Grab and chip samples from other exposures of this zone commonly assay 1-7 g/t gold. This zone has been intermittently exposed over a strike length of 90 m and its EM-16 signature suggests it may be at least 350 m long. A ten-metre wide stratabound zone of calc-silicate alteration with up to 5 disseminated arsenopyrite and low gold values occurs 20 rn south of and parallel to the main zone. Several stratabound iron carbonate+mariposite/fuchsite zones up to 4 m wide and carrying low gold values occur in the next 120 m of stratigraphy to the south (Assessment report 53B15NW0020). DDH C-85-1 returned up to 2.23 ppm Au over 1.3 feet (0.4 m) from a quartzite-grunerite iron formation with indistinctly banded to disseminated arsenopyrite (10%), pyrrhotite (5%), and pyrite (5%) with local vugs and cross-cutting pyritic fractures (Assessment report 53B15NW0018). Sampling done by OGS staff on the SW shore of Castor Lake returned assays of 0.02 to 0.04 oz/t Au ( ) and 2.88 to 11.8% As (Bartlett et al., 1985).
| Commodity | Analytical Method | Digestion Method | Result | Unit | Limit | Qualifier |
|---|---|---|---|---|---|---|
| Gold | Unknown | 2230 | ppb |
Map - Geological series, Precambrian geology, Eyapamikama Lake area, (Opapimiskan Lake project), Kenora District (Patricia Portion)
Publication Number: P2834 Scale: 1:31,680 Date: 1985
Author: Bartlett J.R., Breaks F.W., de Kemp E.A., Shields H.N.
Publisher Name: Ontario Geological Survey
Location:
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