Ontario Mineral Inventory

Ontario Geological Survey
Permanent Link to this Record: MDI52F07NW00011

Record: MDI52F07NW00011

General

Commodities

Primary Commodities: Gold

Location

Township or Area: Harper Lake Area

Latitude: 49° 24' 47.97"    Longitude: -92° 45' 43.57"

UTM Zone: 15    Easting: 517256.001   Northing: 5473431.997    UTM Datum: NAD83

Resident Geologist District: Kenora

NTS Grid: 52F07NW

Point Location Description: Transfer

Location Method: Conversion from MDI

Access Description: The Leuiller Island occurrence is located approximately 50 km south of the City of Dryden. Leuiller Island is situated in the northern part of Upper Manitou Lake. Access to Upper Manitou Lake is gained by an all-terrain vehicle (ATV) trail that departs from Highway 502. Travel on Upper Manitou Lake is via watercraft. (OGS OFR 6180, p. 15; 2006)

Assessment Work on File

Geology

Province: Superior

Subprovince: Wabigoon

Terrane: Western Wabigoon

Belt: Eagle-Wabigoon-Manitou

Geological Age: Precambrian  

Mineralization Comments

Feb 24, 2010 (C Ravnaas) - Leuiller Island is underlain by rocks that comprise the Upper Manitou Lake assemblage, which is part of the Eagle-Wabigoon-Manitou lakes greenstone belt (Blackburn 1982). A majority of gold occurrences in the Upper Manitou Lake area are controlled by northeast-trending shear and fracture zones. Parker (1989, p.109) describes mineralizing events as "gold-bearing quartz veins hosted by sheared and fractured felsic sills and dikes, metavolcanics rocks, and along dike/sill-metavolcanic contacts." The northeast-trending Manitou Anticlinal Axis is a prominent structural feature in the Upper Manitou Lake area (Blackburn 1982). The axial plane of this anticline traverses the central part of Leuiller Island. Figure 4 illustrates the location of the anticline and the area examined during this visit. Canamerica Precious Metals Inc. conducted an extensive exploration program in the Upper Manitou Lake area in the mid-1980s. A majority of the exploration efforts by this company concentrated on the peninsula that separates Manitou Straits from Upper Manitou Lake. The only documented exploration work performed on Leuiller Island was by Canamerica during this program. Several strained and altered zones were discovered during their bedrock mapping on Leuiller Island. These zone are more abundant and are larger in size near the southern part of the island. Grab samples of altered mafic rocks related to these zones, during this program, returned up to 18.24 g/t Au (Kenora District Office, assessment files, 52F/07SW X-4). Outcrops were examined and sampled by District staff as part of a traverse across the south part of the island. All rocks examined were highly strained and show various amounts of silicification, carbonatization and chloritization. Fractures related to strain trend in a northeast direction parallel to regional deformation and the Manitou Lake Anticline. Samples presented in Table 4 were collected to provide a representation of various alteration and rock types examined during this visit. A northeast-trending shear zone, orientated parallel to the contact of the felsic and mafic volcanic rocks, illustrated in Figure 5, was discovered during the bedrock mapping program by Canamerica (Kenora District Office, Assessment Files, 52F/07SW X-4). The Leuiller Island gold occurrence, located on the southeast shore, is associated with these strained rocks. The strained felsic intrusive rocks related to the occurrence are approximately 3 m wide. Massive, white quartz veins intrude the felsic intrusive rocks. These quartz veins intrude along fractures, but also display a stockwork pattern. Mineralization in this area was tested with 3 diamond-drill holes. A significant drill intersection included a section which assayed 24.69 ppb Au in hole number LL84-2 (Kenora District Office, assessment files, 52F/07SW X-6). All samples collected from this visit returned anomalous gold values. Gold content is not associated with a specific rock or alteration type. There were a minor number of quartz veins observed in the exposures examined. The only quartz veins discovered were located in felsic intrusive rocks. Gold values associated directly with the felsic intrusive rocks were higher than samples collected from quartz veins than cut these units. This area of Upper Manitou Lake should be examined based on the elevated values from samples collected during this visit. (OGS OFR 6180, p. 15-17; 2006)

Mineral Record Details

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