Ontario Mineral Inventory

Ontario Geological Survey
Permanent Link to this Record: MDI000000001922

Record: MDI000000001922

General

Commodities

Primary Commodities: Palladium, Platinum, Copper, Gold

Location

Township or Area: Shelby Lake Area, Lac Des Iles Area

Latitude: 49° 7' 27.3"    Longitude: -89° 31' 37.03"

UTM Zone: 16    Easting: 315641   Northing: 5444343    UTM Datum: NAD83

Resident Geologist District: Thunder Bay South

NTS Grid: 52H04NE

Point Location Description: GPS point from N. Pettigrew

Location Method: Field Visit with GPS

Access Description: Access to the Legris Lake Property is obtained by travelling approximately 20 km east on Highway 11/17 from Thunder Bay, then 81 km north along provincial highway 527. From there, Fensom Road (gravel) leads to the claim group 16 km to the west. From kilometers 16 and 17 of Fensom Rd, trench and drill sites can be reached via a network of secondary and tertiary roads and access trails

Exploration History

1999: prospector K. Fenwick discovered the Main Showing Zone. 1999-2002: Avalon Ventures Ltd. and Starcore Resources Ltd. optioned the property and conducted IP and magnetic geophysical surveys, geological mapping, geochemical surveys, trenching, sampling, and drilled 28 DDH totaling 4633 m. The Poplar Zone was discovered in 2000. 2004: North American Palladium Ltd. (NAP) optioned the property and conducted prospecting and trenching. 2005: NAP drilled 3 DDH totaling 465 m and conducted airborne magnetic and VLF-EM surveys. Option was dropped and property returned to K. Fenwick. 2006: property was optioned by Abitibi Mining Corp. who conducted a ground magnetometer survey. 2010: Lac des Iles Mines Ltd. optioned the property, drilled 7 DDH totaling 3942.6 m, and conducted trenching. 2011: Lac des Iles conducted trenching and drilled 4 DDH totaling 2168 m.

Assessment Work on File

Geology

Province: Superior

Subprovince: Wabigoon

Geological Age: Archean  

Geology Comments

May 20, 2016 (Therese Pettigrew) - The Legris Lake property is situated within the Archean Wabigoon Subprovince of the Superior Structural Province. The Legris Lake Complex is part of a series of PGE-bearing mafic-ultramafic intrusions that form a circular pattern approximately 30 km in diameter commonly referred to as the "Ring of Fire". The series primarily intrude metasediments and metabasalts near the Wabigoon-Quetico Subprovince boundary. The series include the Lac des Iles Complex, Tib Lake, Towle Lake, Wakinoo Lake, Demers Lake, Taman Lake, Buck Lake, and Dog River intrusions. The Legris Lake Complex is intruded by late granodiorite dykes and quartz feldspar pegmatites part of larger granodiorite plutons forming the sanukatoid suite of rocks. The Legris Lake Complex has later been intruded by Proterozoic-age diabase dykes and sills (AFRI 20000000847).

Lithology

Mineralization

Mineralization Comments

May 20, 2016 (Therese Pettigrew) - The Poplar Zone is located in the northeastern part of the northwestern border zone. It consists of Cu-Pd-rich mineralized leucogabbro similar to the Main Showing Zone. The Poplar Zone has produced the highest grade mineralization thus far discovered in the Complex, with samples grading up to 2.04 g/t Pd, 0.41 g/t Pt, 0.71 g/t Au, 0.42% Cu over 9.95 m (hole L00-08) and 4.50 g/t Pd, 0.62 g/t Pt, 0.20 g/t Au, 0.50% Cu over 0.97 m (hole L01-14). Due to the complex nature of the Poplar Zone, it has been further subdivided into two sub-zones referred to as the hole 4 (L00-04) and hole 8 (L00-08) mineralization. Hole 8 Mineralization has been intersected by hole L00-08 and L01-16, consists of Cu-Ni-PGE mineralized, sulphide rich (~10%) leucogabbro intercalated with unmineralized melanogabbro to clinopyroxenite. Great difficulty has been encountered in interpreting the hole 8 mineralization due to the inability to extend the known mineralization by drilling or trenching. Hole 4 Mineralization is the best preserved example of primary, magmatic Cu-Ni-PGE mineralization found thus far in the northwestern border zone. It consists of an unmineralized, strongly chloritized clinopyroxenite-pyroxenite basal unit overlain by a Cu-Ni-PGE bearing, sulphide-rich leucogabbro unit, the upper most portion of which (1 to 5 metres) is unmineralized. It has been exposed in Trench 5, for nearly 100 metres of strike length and was intersected by holes L00-04, L01-14 and 16. The hole 4 mineralization is similar in mineralogical composition to the hole 8 mineralization consisting of pyrite ± pyrrhotite + chalcopyrite + pentlandite ± millerite + magnetite. The Poplar and Main Showing Zone’s leucogabbro is geochemically nearly identical. However, the Cu-Ni-PGE mineralization of the Poplar Zone is much more magnetite-rich (~2-3 vol%) and overall more sulphide-rich (5-10 vol%) mostly due to a greater pyrite ± pyrrhotite content. The geology exposed in northwestern part of Trench 5 displays gross large-scale layering of gabbroic units, which is disturbed by later slumping and inclusion of numerous, large (up to 20 metre) metasedimentary xenoliths. In the northern end of the mineralized sill-shaped body exposed in Trench 5 the basal clinopyroxenite-pyroxenite unit has been injected into the overlying leucogabbro, brecciating it. The Poplar Zone also contains a voluminous amount of late granodiorite dykes. The hole 4 mineralization exposed in Trench 5 is strongly brecciated by granodiorite stockworks blasting out from thin (few centimetre) dykes exploiting various joints, faults, and contacts within the zone. These late granodiorite dykes have been a major problem due to their habit of cutting off or greatly reducing the thickness of Cu-Ni-PGE mineralized zones intersected in drill core. All holes in the Poplar Zone that have encountered Cu-Ni-PGE mineralization have intersected varying amounts granodiorite dykes within these mineralized intersection. The greater abundance of granodiorite dykes in the Poplar Zone compared to the Main Showing and Stonefish Lake Zones is due to its proximity to the contact of the heterogeneous northwestern border zone with the homogenous mesogabbro of the central zone. This contact is a major structural and compositional break in the Complex and acted as focus for alteration and granodiorite magmatism (AFRI 52H03NW2008).

Mineral Record Details

References

Map - Precambrian Geology of the Southwest Portion of the Nipigon Embayment, Northwestern Ontario

Publication Number: P3580 Scale: 1:100,000    Date: 2006

Author: Hart T.R.

Publisher Name: Ontario Geological Survey

Map - Precambrian Geology, Lac des Iles Area

Publication Number: P3532 Scale: 1:50,000    Date: 2003

Author: Stone D., Fell M., Daley A., Schnieders B.R., Scott J.F., Nielsen P., Wagner D.

Publisher Name: Ontario Geological Survey

Publication - Palladium-Copper-rich Platinum-Group Element Mineralization in Legris Lake Mafic-Ultramafic Complex, Western Superior Province

Publication Number: AppSci Scale:     Date: 2002

Author: Pettigrew, N.T., Hattori, K.H.

Publisher Name: Applied Earth Science, Volume 111, Issue 1, 2002

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For detailed information regarding this mineral record please contact the Thunder Bay South Resident Geologist District Office