Ontario Mineral Inventory

Ontario Geological Survey
Permanent Link to this Record: MDI52F07SW00022

Record: MDI52F07SW00022

General

Commodities

Primary Commodities: Gold

Location

Township or Area: Lower Manitou Lake Area

Latitude: 49° 22' 15.58"    Longitude: -92° 48' 34.55"

UTM Zone: 15    Easting: 513822.772   Northing: 5468716.353    UTM Datum: NAD83

Resident Geologist District: Kenora

NTS Grid: 52F07SW

Point Location Description: Transfer

Location Method: Conversion from MDI

Access Description: The Manitou Lake Property is situated in the District of Kenora, of Northwestern Ontario, approximately 45 kilometers south of the town of Dryden (Figure 1). The property is within NTS quadrangle 52F/7 and the claims are recorded on the Lower Manitou Lake claimImaP (G-2683) and the Harper Lake claim map (G- 2584) (Figure 2). The property lies between longitudes 93°48'W and 93°53'W and latitudes 49°20'30"N and 49°24'N. Access to the.property is via float and/or ski equipped aircraft provided by Swanair Ltd. of Dryden, Ontario. Two alternate land routes originate from Highway 512. The "Goldrock Road" is a narrow, five-mile winter road which follows along the northshore of Kabagukski (Mud) Lake and terminates at the Goldrock townsite (Upper Manitou Lake landing), approximately 9 kilometers by water, east of the property. A second land access route is provided by a 10 mile all-weather lumber road connecting the northern end of upper Manitou Lake at Jonas (Bell) Lake to Highway 512. This road has not been used in recent years and is in poor repair particularly within 1.5 miles of Jonas Lake. (Assessment File 52F07SW U-16, St. Joe Canada Inc., Kenora Resident Geologist Office)

Assessment Work on File

Geology

Province: Superior

Subprovince: Wabigoon

Terrane: Western Wabigoon

Belt: Eagle-Wabigoon-Manitou

Geological Age: Precambrian  

Geology Comments

Feb 23, 2010 (D Scholtz) - The Manitou Lake Property is located in the Manitou-Stormy Lakes portion of the Archean Wabigoon Greenstone Belt of Northwestern Ontario. The property is underlain by the mafic metavolcanic sequence of the Blanchard Lake Group and intermediate pyroclastic volcanics of the overlying Upper Manitou Lake Group. The contact strikes roughly northeast, extending from the Carleton Lake quartz-monzonite stock to Reliance Bay, where the contact is offset by a north-south striking fault with left-lateral displacement in the order of 550 to 650 meters (?). On the east side of this fault, the contact between these groups cuts through the northern part of Reliance Bay towards eastern Swede Boys Island. Where the contact occurs on land, near the Carleton Lake Stock, the volcanic beds on either side appear conformable although an intervening valley may be evidence of a fault contact. The metavolcanics of the Blanchard Lake and upper Manitou Lake Groups strike roughly north-south on the southern Reliance grid but gradually change to a northeastward strike (45-65°) over much of the property. Dips are fairly consistently 60-85° southeast over the claim group. Variability is most prominent in the pillowed units. Pillowed units indicate that the top of the stratigraphic column is to the southeast. The Blanchard Lake Group underlies all of the Reliance Grid area. It is characterized by interbedded and interfingered tholeiitic and gabbroic basalt to andesitic pillowed flows and coarse-grained often porphyritic, "gabbroic" basal t flows. The pillowed flow units are commonly associated with flow breccia units, increasing in abundance to the northeast. The pillowed units and flow breccia units have been exposed to varying degrees of selective epidotization and silicification. Altered pillow cores is particularly characteristic of the pillowed mafic flow units in the Reliance North Shore area. Stratigraphic relationships between the coarse-grained (porphyritic) "gabbroic" basalt flow units and the interbedded and interfingered flow units, suggests some metamorphic overprint which may have altered some primary textural characteristics. This is further supported by the occurrence of the coarse “gabbroic” texture in some pillow cores. The upper Manitou Lake Group is characterized by dominantly fragmental pyroclastic rocks, often crystal-rich, intermediate in composition. The coarseness of the pyroclastics supports the long accepted model of a proximal vent. Rare mafic flow units, interbedded with the intermediate pyroclastics of the Upper Manitou Lake Group, are compositionally and texturally similar to mafic flows of the earlier Blanchard Lake Group, and may be derived from a more distant semi-dormant vent. The Carleton lake Stock is exposed in the southern part of the claim block. This quartz monzonitic pluton intrudes both the Blanchard Lake and upper Manitou Lake metavolcanics. The quartz monzonite is flanked by an unaltered, coarse-grained, porphyritic “gabbroic" basalt flow, of the Blanchard Lake Group, on the west. To the north, the felsic stock intrudes intermediate pyroclastics of the upper Manitou Lake Group, with many small monzonitic offshoots, quartz veining (minor pyrite, minor chalcopyrite and sphalerite locally) and minor alteration. The other significant intrusive rock on the property is the dioritic to quartz dioritic hypabyssal core, exposed on Frenchman Island and the west sides of North and South Islands. Distinctively blue quartz is characteristic of the equigranular to slightly feldspar-phyric quartz diorite.

Mineralization

Mineralization Comments

Feb 23, 2010 (C Ravnaas) - Best assay: 0.19 opt Au on surface. During the 1985 field season, gold mineralization was identified in three major areas: 1. The Peninsula Zone to the south of Frenchman Island was previously identified by Anaconda. Visible gold occurs in a thin (approx. 1.5 cm) rusty quartz veinlet that occurs within a one meter wide basalt dike. The veinlet subparallels the dike, then cuts across and runs along the margin of the dike, adjacent to Intermediate Tuff Breccia. The quartz veinlet, carrying gold, has a four to six centimeter halo containing 8-10% pyrite and up to 0.19 opt Au. The basalt dike can be traced 30 meters but the gold-bearing quartz veinlet is traceable over only 10 meters where it splits into very thin, unmineralized stringers. The area contains abundant intensely sheared (50-60°) sericite schist. Detailed mapping (1:500) and sampling (Plan 3) has shown the sericite schist to return background, to slightly anomalous Au values (72 ppb over 0.5m; 159 ppb over 3.7m). Felsite dikes within this area have returned up to 175 ppb Au. Highly anomalous values are restricted to the quartz veinlet containing VG and the pyritic halo. The intermediate tuff breccia adjacent to the basalt dike returned up to 640 ppb Au over 1.2m and 205 ppb Au over 0.5m. This gold-bearing zone is closely associated with a 70° fault that has been identified as cutting through the peninsula. The intense shearing associated with this fault would have provided ample conduits for hydrothermal and mineralizing fluids. The oxidized, intensely sheared sericite schist appears to be derived from intermediate tuff breccia based on field observations. The alteration and shearing does not appear to have been lithology specific, but extensive alteration is evident. The large volume of hydrothermally altered intermediate pyroclastic is a potential source of gold, which may have been leached out, transported along this highly fractured fault and associated shear zone, and possible concentrated nearby. The VG seen in the quartz veinlet may be one, such area, occurring towards the flank of the broad shear zone. The association of the gold-bearing quartz veinlet with a basalt dike may suggest a genetic link between late stage mafic igneous activity and gold mineralization in this area. A single gold-bearing quartz veinlet is exposed on the Peninsula southeast of North Island. Follow-up mapping (Plan 3) identified a significant fault zone associated with intensely altered and sheared tuff immediately adjacent to the auriferous veinlet. The geological environment and the presence of visible gold make this area a favourable exploration target. (Assessment File 52F07SW U-16, St. Joe Canada Inc., Kenora Resident Geologist Office)

Mineral Record Details

References

File - Resident Geologist files AF 52F07SW U-16

Publication Number: Date: 1996

Author:

Publisher Name:

Location: Kenora RGP

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For detailed information regarding this mineral record please contact the Kenora Resident Geologist District Office