Ministry of Energy, Northern Development and Mines
Permanent Link to this Record: MDI000000001768| Deposit Name(s) | Mount Baldy - 1860 |
|---|---|
| Deposit Status | occurrence |
| Abandoned Mine Inventory Reference | 08575 |
| Date Created | 2014-Oct-15 |
| Date Last Modified | 2020-Mar-24 |
| Created By | M A Puumala |
| Revised By | T Pettigrew |
Primary Commodities: amethyst
Township or Area: Macgregor
Latitude: 48° 31' 5.54" Longitude: -89° 8' 58"
UTM Zone: 16 Easting: 341278 Northing: 5376130 UTM Datum: NAD83
Resident Geologist District: Thunder Bay South
NTS Grid: 52A11SE
Point Location Description: Trench, AMIS site location 08575
Location Method: amis site visit
Access Description: The Mount Baldy occurrence is located immediately south of Mount Baldy Road, approximately 400 m east of the intersection with Highway 527.
1860s: Test pit sunk on amethystine quartz vein located 2 km northeast of the Thunder Bay Mine. 1976: manual and mechanical stripping by D. Galley, J. Nelson and C. Dutchak. 1990-91: Geological, VLF-EM and magnetometer surveys, mechanical stripping and sampling by T. Twomey and B. Smith. 1998-2001: Trenching and diamond drilling by B. Smith.
| Office File Number | Online Assessment File Identifier | Online Assessment File Directory |
|---|---|---|
| 2.14041 | 52A11SE0001 | Open |
| 63.5738 | 52A11SE0002 | Open |
| 2.19107 | 52A11SE2002 | Open |
| 2.21905 | 52A11SE2005 | Open |
| OP91-002 | 42C16SE0002 | Open |
Province: Southern
Subprovince: Animikie Supergroup
Geological Age: Mesoproterozoic
10/16/2014 (M A Puumala) - The Mount Baldy amethyst occurrence is located at an approximately northeast-striking fault contact between Archean mafic metavolcanic rocks to the northwest, and rocks of the Paleoproterozoic Gunflint Formation to the southeast. The Gunflint Formation rocks at this location are comprised of chert and argillite (Twomey 1990 AFRI52A11SE0001). The northeast-striking fault is occupied by an amethystine quartz vein where a 2.5 x 2.0 x 3.0 m deep test pit was sunk during the 1860s. A stripped bedrock exposure on a hill located to the northeast of the pit exposes a 10 m wide network of amethystine quartz veins that are mineralized with disseminated chalcopyrite and galena, while the Gunflint Formation host rocks are mineralized with variable quantities of pyrite. Grab samples from this zone that were assayed for gold and silver did not return any significant results (Twomey 1990).
| Rock Type | Rank | Composition | Texture | Relationship |
|---|---|---|---|---|
| mafic metavolcanics | 1 | |||
| metasedimentary | 2 | chert and argillite | ||
| vein | 3 | is |
| Rank | Mineral Name | Class | Economic Mineral Type | Alteration Mineral Type | Alteration Ranking | Alteration Intensity | Habit Description |
|---|---|---|---|---|---|---|---|
| 1 | amethyst | economic | ore | ||||
| 2 | chalcopyrite | economic | ore | ||||
| 3 | galena | economic | ore | ||||
| 4 | pyrite | economic | ore |
| Rank | Classification |
|---|---|
| 1 | vein |
Publication - Amethyst in the Thunder Bay Area
Publication Number: OFR5891 Date: 1994
Author: Garland, M.I.
Publisher Name: OGS
Publication - Geology of MacGregor Township
Publication Number: OFR5719 Date: 1990
Author: Scott, J.F.
Publisher Name: OGS
Map - Geological series, Precambrian geology, MacGregor Township, west half, District of Thunder Bay
Publication Number: P2984 Scale: 1:15 840 Date: 1986
Author: Scott, J.F., Sequin, J.M.
Publisher Name: OGS
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For detailed information regarding this mineral deposit please contact the Thunder Bay South Resident Geologist District Office