Ontario Geological Survey
Permanent Link to this Record:
MDI52F13SE00048
| Record Name(s) | Harrison Mica - 1984 |
|---|---|
| Related Record Type | Simple |
| Related Record(s) | |
| Record Status | Occurrence |
| Date Created | 1984-Feb-09 |
| Date Last Modified | 2023-May-25 |
| Created By | |
| Revised By |
Primary Commodities: Niobium, Tantalum, Mica
Secondary Commodities: Tourmaline
Township or Area: Bridges
Latitude: 49° 51' 55.77" Longitude: -93° 39' 15.42"
UTM Zone: 15 Easting: 452979 Northing: 5523881 UTM Datum: NAD83
Resident Geologist District: Kenora
NTS Grid: 52F13SE
Point Location Description: Precise
Location Method: Conversion from MDI
1952: H.R. Harrison discovered the showing and an adit was driven into the pegmatite. 1953-54: 6 DDH were drilled. 1954-55: A test sample of mica was shipped to General Electric Co for evaluation.
May 25, 2023 (Therese Pettigrew) - The area is underlain by mafic metavolcanics and mafic intrusive rocks intruded by late stage granitoid pegmatites. Mapping by Pryslak (1976) indicates the pegmatite is part of a larger pegmatitic granitoid body that extends 2.4 km to the west. The body is described as a dike but seems sill-like in the vicinity of the workings. A horizontal adit and several diamond drill holes intersect muscovite zones. The rock is muscovite-quartz-microcline pegmatite with accessory tourmaline, biotite, and tantalite. This body is zoned but the extent of the zoning is not evident in the exposures (Storey, 1990).
| Rank | Mineral Name | Class | Economic Mineral Type | Alteration Mineral Type | Alteration Ranking | Alteration Intensity | Alteration Style |
|---|---|---|---|---|---|---|---|
| 1 | Microcline | Economic | Gangue | ||||
| 2 | Quartz | Economic | Gangue | ||||
| 3 | Biotite | Economic | Gangue | ||||
| 4 | Muscovite | Economic | Gangue | ||||
| 5 | Tourmaline | Economic | Gangue | ||||
| 6 | Garnet | Economic | Gangue | ||||
| 7 | Columbite | Economic | Gangue |
May 25, 2023 (Therese Pettigrew) - The muscovite-bearing pegmatite trends easterly through the centre of the claim, dips subvertically, and has a maximum width of 150 feet (46 m). Microcline, perthitic microcline, and quartz are the major mineral constituents, and biotite, muscovite and tourmaline occur in lesser amounts. Minor blue-green garnet and rare tantalite-columbite have also been identified by D. P. Parrott (personal communication). Black tourmaline locally forms up to 10 percent of the pegmatite mass and can be readily observed in the dike, between 100 and 300 feet (30 and 90 m) west of the adit. Individual crystals range up to 10 inches (25 cm) in length and 2 1/2 inches (5.3 cm) in diameter. Biotite books, up to 5 inches (13 cm) in diameter, and 2 inches (5 cm) thick, form about 5 percent of the pegmatite mass. Muscovite is segregated in small lenses in the pegmatite. The largest muscovite zone occurs near the entrance of the adit, strikes easterly, and dips vertically. The zone has a maximum thickness of 2 feet (0.6 m) and can be traced on the surface for a distance of 30 feet (9 m). The east end of the zone is under water. A 50-foot (15 m) horizontal diamond drill hole, located about 200 feet (60 m) west of the adit, intersected a muscovite-bearing zone about 20 feet (6 m) wide. The muscovite has a light greenish brown colour and forms books up to 18 inches (46 cm) in diameter, and up to 5 inches (13 cm) thick. Most of the larger books contain structural imperfections known as 'A* reeves and wedge structure (Pryslak, 1976). Assays of grab samples from near the adit indicate up to 1.85% Nb2O5 and 0.17% Ta2O5 (Storey, 1990).
MonoMap - Geology of the Bruin Lake-Edison Lake area, District of Kenora
Publication Number: R130 Page: 41-42 Date: 1976
Author: Pryslak A.P.
Publisher Name: Ontario Division of Mines
Location:
Mono - An evaluation of the industrial mineral potential of parts of the districts of Kenora and Rainy River
Publication Number: OFR5718 Page: 140-142 Date: 1990
Author: Storey C.C.
Publisher Name: Ontario Geological Survey
Location:
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