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Ontario Geological Survey
Permanent Link to this Record:
MDI000000002246
| Record Name(s) | Berger Amethyst - 1992, Echo Lake - 1993 |
|---|---|
| Related Record Type | |
| Record Status | Occurrence |
| Date Created | 2018-Dec-06 |
| Date Last Modified | 2021-Dec-06 |
| Created By | Therese Pettigrew |
| Revised By | Therese Pettigrew |
Primary Commodities: Amethyst
Secondary Commodities: Fluorite
Township or Area: Marks
Latitude: 48° 19' 36.57" Longitude: -89° 52' 49.88"
UTM Zone: 16 Easting: 286497 Northing: 5356637 UTM Datum: NAD83
Resident Geologist District: Thunder Bay South
NTS Grid: 52A05SW
Point Location Description: UTM location from OGS staff member L. Ratcliffe
Location Method: Field Visit with GPS
1992: Amethyst veins discovered in the area east of Echo Lake by the Ontario Geological Survey (Berger 1993) while mapping Marks Township. 1992: T. Twomey and B. Smith staked the property and carried out a magnetometer and VLF-EM survey. 1997: J. Hakala purchased the property. 1998-99: J. Hakala carried out trenching, stripping, and blasting. Up to 100 lb of material was removed from the site under an aggregate permit.
| Office File Number | Online Assessment File Identifier | Online Assessment File Directory |
|---|---|---|
| 2.19659 | 52A05SW2001 | 52A05SW2001 |
| 2.15664 | 52A05SW0020 | 52A05SW0020 |
Province: Superior
Geological Age: Neoarchean
| Rock Type | Rank | Composition | Texture | Relationship | Vein | 1 | Host |
|---|---|---|---|---|
| Breccia-unsubdivided | 2 | Host | ||
| Granitoid-Unsubdivided | 3 | Granite To Granodiorite | Medium- To Coarse-Grained | Adjacent |
| Rank | Mineral Name | Class | Economic Mineral Type | Alteration Mineral Type | Alteration Ranking | Alteration Intensity | Alteration Style |
|---|---|---|---|---|---|---|---|
| 1 | Amethyst | Economic | Ore | ||||
| 2 | Galena | Economic | Ore | ||||
| 3 | Chalcopyrite | Economic | Ore | ||||
| 4 | Fluorite | Economic | Ore | ||||
| 1 | Quartz | Economic | Gangue |
Dec 06, 2018 (Therese Pettigrew) - Amethyst veins in this area were initially reported by Berger (1993 OFR5862) and Rogers and Berger (1995 R295), who also reported the discovery of significant amethyst mineralization approximately 900 m southwest of the current stripped area at a location 600 m east of the north end of Echo Lake. The following description of the veins located near Echo Lake is provided by Berger (1993): �Here six veins hosted in pink weathering granodiorite were found over an area of 30 m by 5 m. Four veins are northeast striking and the other two strike easterly. The most easterly vein (No. 1) contains well developed smokey quartz crystals and minor galena, chalcopyrite and less commonly green fluorite were observed. The vein is vuggy and there is extensive silicification of the foot wall. The three other northeast-striking veins contain large (up to 4 cm in size) clear, purple and dark purple amethyst crystals. The largest and darkest purple crystals were obtained from a vein exposed over 1 m along strike at the edge of a talus slope (vein 5). Only limited stripping of this vein was undertaken by the field crew. Each of these three veins dips between 65� and 85� to the east and in each of these three veins the best crystals are developed on the hanging wall. The two easterly striking veins contain well formed, white to purple crystals up to 2 cm in size. One of these veins (vein 3) contains smoky and purple crystals with the colour concentrated in the points and along the crystal septa. Vein 6 contains well formed, clear and frosted crystals up to 1 cm in size resting on botyroidal clear and purple fluorite.� T. Twomey describes the showing as narrow, vuggy veins averaging 0.1 to 0.4 m wide with excellent crystal terminations of smokey, black, lavender, and purple amethyst along with purple to white fluorite and galena (Assessment file 52A05SW0020).
| Rank | Classification |
|---|---|
| 1 | Vein |
Map - Precambrian Geology, Marks Township
Publication Number: P3195 Scale: 1:15,840 Date: 1993
Author: Berger B.R.
Publisher Name: Ontario Geological Survey
MonoMap - Geology of Adrian and Marks Townships
Publication Number: OFR5862 Scale: Date: 1993
Author: Berger B.R.
Publisher Name: Ontario Geological Survey
Map - Precambrian Geology, Marks Township
Publication Number: M2618 Scale: 1:20,000 Date: 1995
Author: Berger B.R.
Publisher Name: Ontario Geological Survey
MonoMap - Precambrian Geology, Adrian, Marks, Sackville, Aldina and Duckworth Townships
Publication Number: R295 Scale: Date: 1995
Author: Rogers M.C., Berger B.R.
Publisher Name: Ontario Geological Survey
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For detailed information regarding this mineral record please contact the Thunder Bay South Resident Geologist District Office