Ontario Geological Survey
Permanent Link to this Record:
MDI52A10NE00016
| Record Name(s) | Big Pearl Lake - 1931 |
|---|---|
| Related Record Type | Partial |
| Related Record(s) | |
| Record Status | Occurrence |
| Date Created | 1991-Mar-22 |
| Date Last Modified | 2022-Apr-26 |
| Created By | |
| Revised By |
Primary Commodities: Amethyst
Secondary Commodities: Lead
Township or Area: McTavish
Latitude: 48° 40' 18.14" Longitude: -88° 39' 55.05"
UTM Zone: 16 Easting: 377400 Northing: 5392300 UTM Datum: NAD83
Resident Geologist District: Thunder Bay South
NTS Grid: 52A10NE
Point Location Description: SE corner of Big Pearl L., McTavish Twp., NW part of SW 1/4 of Lot 5, Conc. III
Location Method: Conversion from MDI
Access Description: Hwy. 11/17 east to Pearl, then Road 5 North to the first left after the railway tracks. Follow this road for 0.7 km. Just after the power lines there is a logging road on the left side which leads to the showing.
1931: Tanton describes several trenches in the vicinity of Big Pearl Lake, some up to 137 m in length. 2003: T. Twomey carried out prospecting and stripping. 2004: L. Kowtuski carried out prospecting, stripping, trenching, and mapping. 2005: L. Kowtuski carried out prospecting, mapping and sampling.
| Office File Number | Online Assessment File Identifier | Online Assessment File Directory |
|---|---|---|
| 2.28707 | 52A10NE2021 | 52A10NE2021 |
| 2.27606 | 52A10NE2017 | 52A10NE2017 |
| 2.28537 | 52A10NE2020 | 52A10NE2020 |
| 2.30135 | 20000000509 | 20000000509 |
Province: Superior
Subprovince: Quetico
Geological Age: Archean
| Rock Type | Rank | Composition | Texture | Relationship | Granite | 1 | Host |
|---|---|---|---|---|
| Vein | 2 | Amethyst And Quartz | Is |
Feb 25, 2020 (Therese Pettigrew) - The host rocks for the occurrence consist of dark pink, Archean granite with xenoliths of greenish metasediments exhibited good boudinage structures. Coarse-grained feldspar and white quartz pegmatites within the granite are not amethyst-bearing. The amethyst veins occur in the vicinity of the power line, within the pink granite (Garland, 1994).
| Rank | Mineral Name | Class | Economic Mineral Type | Alteration Mineral Type | Alteration Ranking | Alteration Intensity | Alteration Style |
|---|---|---|---|---|---|---|---|
| 1 | Amethyst | Economic | Ore | ||||
| 2 | Sphalerite | Economic | Ore | ||||
| 3 | Galena | Economic | Ore | ||||
| 4 | Pyrite | Economic | Ore | ||||
| 5 | Barite | Economic | Ore |
Feb 25, 2020 (Therese Pettigrew) - Amethyst occurs with vuggy white quartz, usually in thin veins. Sphalerite, galena, pyrite, and barite are present with the quartz (Garland, 1994). The “Far East Pit” is located at NAD83 UTM Zone 16, 377654 m E, 5392440 m N and is on trend with the showing at the SE corner of Big Pearl Lake. All of veins observed so far are spatially related to a single trend at azimuth 045 to 055, therefore are one amethystine vein system (Assessment report 52A10NE2017).
| Rank | Classification |
|---|---|
| 1 | Vein |
| Rank | Characteristic |
|---|---|
| 1 | Vein |
Article - Northwestern Region Industrial Minerals Program - 1987
Publication Number: MP138.007 Page: 165 Date: 1997
Author: Kennedy M.C., Sherlock E.J.
Publisher Name: Ontario Geological Survey
Location:
Map - Geological series, McTavish Township (west part of north half), District of Thunder Bay
Publication Number: P0720 Scale: 1:15,840 Date: 1997
Author: McIlwaine W.H.
Publisher Name: Ontario Dept. of Mines and Northern Affairs
Location:
Publication - Fort William and Port Arthur, and Thunder Cape Map-area, Thunder Bay District, Ontario; Geological Survey of Canada, Memoir 167
Publication Number: GSC Memoir 167 Date: 1931
Author: Tanton, T.L.
Publisher Name: Geological Survey of Canada
Location: https://doi.org/10.4095/100799
Mono - Amethyst in the Thunder Bay Area
Publication Number: OFR5891 Page: 83-84 Date: 1994
Author: Garland M.I.
Publisher Name: Ontario Geological Survey
Location:
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