Ontario Mineral Inventory

Ontario Geological Survey
Permanent Link to this Record: MDI52F15SE00045

Record: MDI52F15SE00045

General

Commodities

Primary Commodities: Lithium, Tantalum, Niobium

Location

Township or Area: Brownridge

Latitude: 49° 49' 28.06"    Longitude: -92° 38' 22.79"

UTM Zone: 15    Easting: 525918   Northing: 5519176    UTM Datum: NAD83

Resident Geologist District: Kenora

NTS Grid: 52F15SE

Point Location Description: Precise

Location Method: Conversion from MDI

Access Description: The Mavis Lake property is approx. 19 km NE by road from Dryden and can be reached from the city by driving east for approx. 8 km on Trans-Canada Highway 17 to the junction with Thunder Lake Road, then travelling approx. 3 km to the intersection of Thunder Lake Road and Ghost Lake South Road. From this point, drive north on Ghost Lake South Road for approx. 1 km and then east along the Mine Road for approx. 4 km, and finally north along a subsidiary gravel road to the eastern claims of the property.

Exploration History

1956: Lun-Echo Gold Mines Ltd. drilled 50 DDH totalling 2234.19 m immediately south of Mavis Lake. Milestone Mines conducted trenching work and limited DD east and southeast of Mavis Lake. 1978: R.J. Fairservice staked the property and then optioned the property to Selco Mining Corp Ltd. 1979-81: Selco conducted geological mapping, lithogeochemical surveys and drilled 8 DDH totalling 351.4 m. 1982: Tantalum Mining Corp of Canada Ltd (Tanco) optioned the Fairservice property and conducted line cutting, a geophysical survey and a lithogeochemical survey. 2002: Emerald Field Resources optioned the property from R.F. Fairservice. 2003: Emerald Field conducted prospecting, trenching, geological mapping, and drilled 4 DDH. 2009: TNR Gold and International Lithium Corp. (ILC) optioned the property from Rich Resource Investments Ltd. ILC conducted geological mapping and sampling. 2011: ILC drilled 20 DDH totalling 1753 m.

Assessment Work on File

Geology

Province: Superior

Subprovince: Wabigoon

Geological Age: Archean  

Geology Comments

May 26, 2015 (Therese Pettigrew) - The property lies within the Sioux Lookout Domain (SLD) in the western Wabigoon Subprovince (WS). The SLD is sandwiched between the granitoid-dominated Winnipeg River Subprovince (WRS) to the north and the greenstone-granite-rich WS to the south. The WS is a granite-greenstone terrain approx. 900 km long, 150 km wide that comprises metavolcanic and subordinate metasedimentary rocks ranging in age from 3.0 Ga to 2.71 Ga and intruded by a suite of 3.0 to 2.69 Ga granitoid batholiths, gabbroic sills and stocks. The 10 by 30 km area within the eastern SLD which is host to numerous rare metal pegmatites in the Dryden area is known as the Dryden Pegmatite Field (DPF), which is populated by two distinct pegmatite clusters occurring roughly 10 km apart: 1) Mavis Lake Pegmatite group (MPG) in the Mavis Lake area, with a 2665+/- 10 Ma age, and 2) Gullwing-Tot Pegmatite group (GPG) in the Gullwing and Tot Lakes areas of unknown mineralization age (Clark et al., 2010).

Lithology

Lithology Comments

May 26, 2015 (Therese Pettigrew) - The underlying Brownridge metasediments within the Mavis Lake area are dominated by wacke with subordinate siltstone strata and have well-preserved primary structures. Structurally overlying metavolcanic rocks (Brownridge volcanics) consist of fine-grained pillowed, massive mafic lavas and medium- to coarse-grained flows and/or gabbroic sills. The upper portion of the metavolcanics tends to be variolitic, massive and pillowed mafic flows. The two-mica granites are the source for rare metal pegmatites in the region, particularly the 2685 Ma Ghost Lake batholith (GLB) in the Mavis Lake area. The GLB is the largest (80 square km) and most fractionated of any peraluminuous granite in the SLD, with 8 internal, subsolvus granitic and pegmatitic granite units. Eleven rare-element granitic pegmatites are known on the Mavis Lake Property and vary in strike length from 11 to >240m, and thicknesses in 0.3 to >2.4m range. These bodies are mainly hosted in the 2733 Ma Brownridge mixed felsic-mafic metavolcanic unit of the Neepawa group that is intensely deformed by at least 4 folding events that culminated with development of a regional shear zone (Wabigoon fault) and metamorphism to middle amphibolite grade. The Mavis Lake Pegmatite group (MPG) consists of a 0.8 to 1.5 by 8 km, east trending swarm of pegmatites and related metasomatic zones hosted mostly within the mafic rocks. Pegmatites of this group exhibit a classic regional zonation with increasing distance from the parent GLB, as defined by systematic changes in mineralogy, chemical association and extent of post magmatic replacement (Clark et al., 2010). The volcanics are Keewatin-type greenstones and in the vicinity of the dykes, there are hornblende schists and pillow lavas. The volcanics strike E-W, dip steeply to the north and appear to be overturned (Vos et al., 1982).

Mineralization

Mineralization Comments

May 26, 2015 (Therese Pettigrew) - The main primary assemblage in Pegmatite 18 consists of muscovite-tourmaline-K feldspar-albite-spodumene-quartz pegmatite, which is considerably less coarse than comparable primary assemblages from the South Zone and on the Fairservice property. Spodumene is usually light green and it ranges in abundance from 23 to 53 volume %. Beryl, columbite-tantalite, and holmquistite are sparse. Small quantities of scheelite are disseminated within calc-silicate pods and layers in mafic metavolcanic rocks situated within up to one metre from the spodumene pegmatite contact. The occurrence of axinite (Ca,Fe,Mn)3Al2BO3Si4O12OH in these calc-silicate domains suggests that boron was introduced from nearby albitized spodumene pegmatites (Clark et al., 2010). "An irregular pegmatite dike trending approximately northwest-southeast outcrops about 1500 feet east of Mavis Lake. Over most of its exposed length of about 700 feet the pegmatite contains some spodumene. The indicated surface width is from 15 to 60 feet, but a hole drilled under the widest surface exposure intersected only 5.9 feet of pegmatite at a depth of about 50 feet. The pegmatite intersection contained about 20% spodumene and assayed 1.20% lithia" (Vos et al., 1982).

Mineral Record Details

Mineral Zones - Size and Shape

References

Publication - Technical Report (NI 43-101) on the Mavis Lake Lithium Property

Publication Number: 2010 43-101 Date: 2010

Author: Clark, G., Breaks, F.W., and Osmani, I.A.

Publisher Name: International Lithium Corporation

Location: SEDAR (under TNR Gold)

Mono - Pegmatite mineral resources of Ontario

Publication Number: IMR021 Page: 48  Date: 1997

Author: Hewitt D.F.

Publisher Name: Ontario Dept. of Mines

Location:

Mono - Industrial minerals of northern Ontario-supplement 1

Publication Number: OFR5388 Page: 123  Date: 1982

Author: Vos M.A., Abolins T., Smith V.

Publisher Name: Ontario Geological Survey

Location:

Map - Precambrian Geology of the Thunder Lake Area

Publication Number: P3529 Scale: 1:20,000    Date: 2003

Author: Beakhouse G.P., Pigeon L.

Publisher Name: Ontario Geological Survey

Location:

Map - Kenora-Fort Frances sheet, geological compilation series, Kenora, Rainy River districts

Publication Number: M2115 Scale: 1:253,440    Date: 1967

Author: Davies J.C., Pryslak A.P.

Publisher Name: Ontario Dept. of Mines

Location:

Map - Precambrian geology, Flambeau Lake-Larson Bay area, western part, District of Kenora

Publication Number: P3111 Scale: 1:4,800    Date: 1988

Author: Parker J.R., Schienbein R.

Publisher Name: Ontario Geological Survey

Location:

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