Ontario Geological Survey
Permanent Link to this Record:
MDI42C13NW00005
| Record Name(s) | Dorothy Lake Sulphide Occurrence - 1992 |
|---|---|
| Related Record Type | Simple |
| Related Record(s) | |
| Record Status | Discretionary Occurrence |
| Date Created | 1996-Nov-25 |
| Date Last Modified | 2022-May-09 |
| Created By | |
| Revised By |
Primary Commodities: Sulphur/Pyrite
Township or Area: Black River Area
Latitude: 48° 59' 3.47" Longitude: -85° 55' 3.45"
UTM Zone: 16 Easting: 579191.83 Northing: 5426274.538 UTM Datum: NAD83
Resident Geologist District: Thunder Bay South
NTS Grid: 42C13NW
Point Location Description: Roadside outcrop Hwy 614 19 km south of Manitouwadge
Location Method: Field Visit
Access Description: The Dorothy Lake sulphide occurrence is located approximately 19 km south of Manitouwadge and 1.25 km south-southwest of the southern end of Dorothy Lake. The occurrence is accessible via motor vehicle. From Manitouwadge proceed south along Highway 614 for approximately 19 km to the vicinity of a small unnamed lake. Sulphide mineralization is exposed in a roadside outcrop located approximately 5 m west of the highway.
1964-1965: Geological mapping; V.G. Milne ( ODM). 1978-1979: Regional lake sediment and water geochemical survey; GSC- MNR. Samples collected in the vicinity of the occurrence contained slightly anomalous amounts of gold. 1983: Airborne geophysical survey (HLEM,VLF-MAG,MAG); Aerodat Limited. 1989: Dighem airborne geophysical survey: Noranda Exploration Company, Ltd. in conjunction and Noranda Minerals Inc. (Geco Division). 1991-1992: Reconnaissance till sampling survey; I.M. Kettles ( GSC). Samples collected in the general vicinity of the occcurrence did not contain anomalous amounts of gold nor base metals. 1992: Lithogeochemical sampling; D.B. McKay (OGS).
Province: Superior
Subprovince: Wawa
Terrane: Wawa-Abitibi
Geological Age: Archean
Dec 07, 2005 (D McKay) - The occurrence is located within the Wawa subprovince and is underlain primarily by granodioritic gneiss of the Black-Pic batholithic complex. Local gneissosity strikes 315 degrees and dips 20 degrees to the east. The occurrence comprises several small (up to 15 cm long by 15 cm wide), rusty gossans which are erratically distributed along the surface of a single roadside outcrop. A reconnaissance survey of the surrounding area failed to locate additional mineralization.
| Rock Type | Rank | Composition | Texture | Relationship | Gneiss-Unsubdivided | 1 | Granodioritic | Cgr, Moderately Foliated | Host |
|---|
| Rank | Mineral Name | Class | Economic Mineral Type | Alteration Mineral Type | Alteration Ranking | Alteration Intensity | Alteration Style |
|---|---|---|---|---|---|---|---|
| 1 | Pyrite | Economic | Ore | ||||
| 2 | Magnetite | Economic | Ore | ||||
| 1 | Quartz | Economic | Gangue | ||||
| 2 | Epidote | Economic | Gangue | ||||
| Quartz | Alteration | Silicification | 1 | Weak | Veins | ||
| Pyrite | Alteration | Pyritic | 2 | Weak | Disseminated | ||
| Epidote | Alteration | Epidotization | 3 | Weak | Veins |
Dec 07, 2005 (D McKay) - The occurrence consists primarily of coarse-grained (5-10 mm across), erratically distributed euhedra of pyrite and magnetite hosted within locally rusty-weathering, coarse-grained, moderately foliated, granodioritic gneiss. The pyrite and magnetite occur in association with quartz and epidote in narrow, variably oriented fractures. Pyrite also occurs as fine-grained, disseminated grains within narrow (1 cm wide), felsic (silicified ?) alteration haloes surrounding the fractures. The pyrite typically constitutes less than 1% of the gneiss, but local concentrations of up to 5% occur within, and proximal to, some of the fractures. The occurrence and the surrounding area are considered to have very little potential to host economic amounts of gold or base metals. A grab sample of rusty-weathering, coarse-grained, moderately foliated granodioritic gneiss containing 2 to 3% very coarse-grained pyrite and magnetite locallized within fractures collected from the occurrence by McKay (1994) in 1992 returned assay values of trace Au and 6 ppm Cu.
| Commodity | Analytical Method | Digestion Method | Result | Unit | Limit | Qualifier |
|---|---|---|---|---|---|---|
| Copper | Unknown | 6 | ppm |
| Rank | Classification |
|---|---|
| 1 | Hydrothermal |
| Rank | Characteristic |
|---|---|
| 1 | Vein |
MonoMap - Geology of the Black River area, District of Thunder Bay
Publication Number: R072 Date: 1968
Author: Milne V.G.
Publisher Name: Ontario Dept. of Mines
Location:
Map - Geophysical Series, White Lake, Thunder Bay District, Ontario
Publication Number: Map 2168G Scale: 1:63,360 Date: 1963
Author: Geological Survey of Canada
Publisher Name: Geological Survey of Canada
Location: https://doi.org/10.4095/116493
Publication - National geochemical reconnaissance release NGR 35-1978, regional lake sediment and water geochemical reconnaissance data, Ontario eastern shore, Lake Superior; Geological Survey of Canada, Open File 555
Publication Number: GSC OF 555 Date: 1979
Author: Hornbrook, E H W; Coker, W B; Lynch, J J
Publisher Name: Geological Survey of Canada
Location: https://doi.org/10.4095/129524
Publication - Regional Lake Sediment and Water Geochemical Reconnaissance Data, northwestern Ontario, [NTS 42C and 42F South]; Geological Survey of Canada, Open File 2362
Publication Number: GSC OF 2362 Date: 1991
Author: Friske, P W B; Hornbrook, E H W; Lynch, J J; McCurdy, M; Gross, H; Galletta, A C; Durham, C C
Publisher Name: Geological Survey of Canada
Location: https://doi.org/10.4095/132202
Publication - Reconnaissance Geochemical Data for Till Samples from the Manitouwadge Area, Ontario
Publication Number: OF 2616 Date: 1993
Author: Kettles, I.M.
Publisher Name: Geological Survey of Canada
Location: https://doi.org/10.4095/183942
Map - Barehead Lake sheet, Thunder Bay District
Publication Number: M2143 Scale: 1:31,680 Date: 1967
Author: Milne V.G.
Publisher Name: Ontario Dept. of Mines
Location:
Mono - Mineral Occurrences in the Manitouwadge Area, Volumes 1, 2 and 3
Publication Number: OFR5906 Date: 1994
Author: McKay D.B.
Publisher Name: Ontario Geological Survey
Location:
File - Schreiber-Hemlo Resident Geologist Mineral Deposit files
Publication Number: Min Dep Date:
Author:
Publisher Name:
Location: Thunder Bay RGP
Map - Manitouwadge-Wawa sheet, geological compilation series, Algoma, Cochrane, Sudbury and Thunder Bay districts
Publication Number: M2220 Scale: 1:253,440 Date: 1972
Author: Milne V.G., Giblin P.E., Bennett G., Thurston P.C., Wolfe W.J., Giguere J.F., Leahy E.J., Rupert R.J.
Publisher Name: Ontario Division of Mines
Location:
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