Ontario Geological Survey
Permanent Link to this Record:
MDI52O04NE00022
| Record Name(s) | Senior Lake - 1986 |
|---|---|
| Related Record Type | Simple |
| Related Record(s) | |
| Record Status | Occurrence |
| Date Created | 1986-Dec-12 |
| Date Last Modified | 2022-Mar-02 |
| Created By | |
| Revised By |
Primary Commodities: Molybdenum
Township or Area: Wesleyan Lake Area
Latitude: 51° 12' 12.05" Longitude: -91° 44' 57.5"
UTM Zone: 15 Easting: 587375.046 Northing: 5673181.514 UTM Datum: NAD83
Resident Geologist District: Thunder Bay North
NTS Grid: 52O04NE
Point Location Description: General
Location Method: Conversion from MDI
OOM sampling 1978.
Province: Superior
Subprovince: Uchi
Terrane: North Caribou
Domain: Uchi
Belt: Birch-Uchi
Geological Age: Archean
Jun 21, 2007 (Mark Puumala) - The Fawthrop-Senior Lakes area is underlain by a narrow (1.1 to 3.9 km wide) east-west-trending supracrustal rock sequence that represents an eastern extension of the Birch-Uchi Greenstone Belt. Sage and Breaks (1982) indicate that the belt is dominated by mafic to intermediate metavolcanic rocks, with only local occurrences of felsic to intermediate metavolcanic and metasedimentary rock. Mafic to ultramafic intrusions have been mapped in the area between Fawthrop and Senior Lakes, while east-west-striking quartz and/or feldspar porphyry dikes are reported to be common in the eastern portions of the belt. The supracrustal rocks are bounded to the north and south by large granitoid intrusions. Sage and Breaks (1982) report that foliation in the Fawthrop-Senior Lakes area generally strikes approximately east-west, and that the supracrustal rocks form a westward-plunging (30 degrees) synform structure. It has also been interpreted that the supracrustal rocks in this belt were likely to have once formed a single continuous sequence eastward linked to similar rocks in the Wesleyan Lake area at the west end of Meen-Dempster Greenstone Belt.
| Rock Type | Rank | Composition | Texture | Relationship | Granite | 1 | Adjacent |
|---|---|---|---|---|
| Porphyry-unsubdivided | 2 | Felsite | Adjacent | |
| Pegmatite | 3 | Near |
| Rank | Mineral Name | Class | Economic Mineral Type | Alteration Mineral Type | Alteration Ranking | Alteration Intensity | Alteration Style |
|---|---|---|---|---|---|---|---|
| 5 | Molybdenite | Economic | Ore | ||||
| 10 | Pyrite | Economic | Ore |
Jun 21, 2007 (Mark Puumala) - The Senior Lake occurrence is described in Wallace (1985) as a mineralized quartz vein that occupies the intrusive contact between a fine- to medium-grained felsite to the south with a weakly foliated granitic intrusion to the north. The mineralized vein is reported to be up to 20 cm thick and is exposed over a strike-length of approximately 25 m. Mineralization in the vein consists of molybdenite (occurring as disseminations, banded disseminations, stringers and paint over a 5 m strike-length) and disseminated pyrite. The felsite material is also reported to be mineralized with disseminated pyrite and cross-cut by epidote stringers. Minor dikelets of coarse-grained to pegmatoid quartz monzonite are also reported to cross-cut the felsite and granitic intrusion. Five additional minor occurrences mineralized with minor pyrite and trace molybdenite +/- chalcopyrite are also reported at various locations along the shore of Senior Lake in Wallace (1985). The occurrence description provided in Wallace (1985) indicates that the vein locally contains up to 15% MoS2. Sage and Breaks (1982) report an assay of 0.36% Mo and 0.61% Bi from this occurrence.
| Rank | Classification |
|---|---|
| 1 | Porphyry |
| Rank | Characteristic |
|---|---|
| 1 | Vein |
MonoMap - Geology of the Ferdinand Lake area, District of Kenora, Patricia Portion
Publication Number: MP109 Scale: Date: 1983
Author: Wallace H.
Publisher Name: Ontario Geological Survey
Location:
MonoMap - Geology of the Slate Falls area, District of Kenora (Patricia Portion)
Publication Number: R232 Scale: Date: 1985
Author: Wallace H.
Publisher Name: Ontario Geological Survey
Location:
MonoMap - Geology of the Cat Lake-Pickle Lake area, districts of Kenora and Thunder Bay
Publication Number: R207 Scale: Date: 1982
Author: Sage R.P., Breaks F.W.
Publisher Name: Ontario Geological Survey
Location:
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