Ontario Mineral Inventory

Ontario Geological Survey
Permanent Link to this Record: MDI52I08NW00012

Record: MDI52I08NW00012

General

Commodities

Primary Commodities: Lithium, Beryllium

Secondary Commodities: Tantalum

Location

Township or Area: Crescent Lake Area

Latitude: 50° 24' 7.35"    Longitude: -88° 27' 18.69"

UTM Zone: 16    Easting: 396585   Northing: 5584345    UTM Datum: NAD83

Resident Geologist District: Thunder Bay North

NTS Grid: 52I08NW

Point Location Description: Stripped pegmatite in drillhole cluster seen on Google Earth

Location Method: Data Compilation

Exploration History

1957: Discovered by prospector Nelson Aubry. 1957: Anaconda Canada drilled 4 DDH totalling 100 m. 1968: J. Donner conducted sampling. 1969: Tantalum Mining Corporation of Canada Ltd. conducted geological mapping and sampling, mag and EM ground geophysical surveys. 1979-80: Cominco conducted line cutting, mag ground geophysical surveys, and geological and soil geochemical surveys. 1999: Gary Clark Consulting conducted sampling. The property was staked by Stares Contracting. 2001: Linear Resources conducted line cutting, prospecting, sampling, stripping, trench mapping, and channel sampling. 2002: Linear Resources conducted trenching, lithogeochemistry, prospecting and drilled 7 DDH totalling 627 m. 2008-09: Linear Metals Corp. conducted line cutting, soil and rock sampling, geological prospecting and mapping, and drilled 6 DDH totalling 868 m. 2012: Linear Metals changed name to Stockport Exploration Inc. 2016: Stockport optioned the Aubry property to Ardiden Ltd, who drilled 2 DDH totalling 104 m on the South Aubry showing. 2018: Ardiden drilled 12 DDH totalling 1904 m. 2021: Green Technology Metals entered into a joint venture agreement with Ardiden, acquiring an 80% interest in the property. Baseline environmental studies were initiated. 2022: Ardiden sold its final 20% interest of the lithium joint venture to Green Technology Metals.

Assessment Work on File

Geology

Province: Superior

Subprovince: Wabigoon

Belt: Caribou Lake

Geological Age: Archean  

Geology Comments

Jun 20, 2011 (N Bennett) - The Seymour Lake property is located in the Caribou Greenstone Belt, which trends ENE along the top of Lake Nipigon, near the northern margin of the Wabigoon Subprovince. A prominent SW-trending portion of the belt wraps around the NW end of a large composite felsic pluton in the property area. The Linear Metals claim group (including KM61 claims) covers a large (1 km x 7 km) lensoid-shaped contact zone between the pluton to the south and metabasalts to the north. The pegmatite dikes are associated with the granitic pluton and intrude the mafic volcanics (pillowed lava, amphibolite, and tuff) that make up the majority of the Seymour Lake property. Pillowed lava in TR-NA-5 shows streching in the N-S direction with stratigraphic tops toward the north (after Pye, 1968). Dykes associated with the contact between the metavolcanics and the felsic pluton are generally coarse-grained and contain spodumene, but not tantalite mineralization. Dikes that have injected farther into the metavolcanics and away from the contact are finer-grained and contain beryl, spodumene and tantalite-columbite mineralization. Typical mineralization at the North Aubry pegmatite is an assemblage of muscovite, spodumene, quartz, K-feldspar and albite +/- manganotantalite +/- beryl +/- apatite +/- lepidolite +/- garnet. The South Aubry pegmatite is characterized by spodumene-bearing feldspathic zones, often with accessory blue to green beryl with locally abundant tantalite in the southernmost trenches.

Lithology

Mineralization

Mineralization Comments

Jun 20, 2011 (N Bennett) - The work carried out by Linear in the summer of 2001 demonstrated the economic possibilities for a significant tantalum deposit(s) in the area. The North Aubry vein has been exposed over a +200 m strike length with widths up to 50 m. Values in the TR-NA-5 area at the south end of the zone reach 2.49 % Ta2O5 over 4 m with the tantalum values in the tantalite indicating extreme fractionation. These values are the highest encountered in Ontario and similar to those from the Tanco Mine in Manitoba, Canada's only tantalum producer. Lithium alteration in the mafic volcanics indicates an intense mineralizing pulse which may have produced stacked zones of pegmatites. Exploration at The South Aubry zone, located 600 m to the south of the North Aubry uncovered coarse tantalite mineralization with significant Ta values; for example: a lepidolite bearing boulder located to the south of the South Aubry near TR-SA-4 yielded Ta2O5 values of 541 ppm (0.054 %). The last drill program at Seymour Lake, testing primarily for tantalum, was completed during August 2002 with a total of 1,866 metres of NQ core drilled in 32 drill holes. The drilling tested the North and South Aubry zones, where lithium (spodumene), tantalum (tantalite), and beryllium (beryl) mineralization is found in shallow dipping granite pegmatites over a strike length in excess of one-kilometre. The zones remain open to the north and south and down dip, and other stacked pegmatites have been located in the area. The 2002 drill program tested the North Aubry zone over a 200-metre strike length with 23 shallow vertical holes (SL-02-1 to 16, SL-02-25 to 31), with 21 of 23 holes intersecting pegmatites hosting Li2O mineralization. In the South Aubry area, drilling tested a 380-metre strike length with eight shallow vertical holes (SL-02-17 to 24), all of which intersected Li2O mineralization. The drill intersections are close to true widths due to the near horizontal to shallow dipping nature of the units. While the drilling was targeted primarily at the tantalum potential of the zones, significant lithium mineralization was intersected in the North Aubry zone including: 1.735% Li2O over 14.25m in SL-02-2, 2.386% Li2O over 9.20m in SL-02-4, 0.955% Li2O over 20.65m including 1.190% Li2O over 14.74m in SL-02-9, 2.212% over 5.70m in SL-02-14, 1.325% Li2O over 23.85m including 2.059% Li2O over 9.00m and 2.232% Li2O over 3.04m in SL-02-27, and 1.475% Li2O over 17.72m including 1.937% Li2O over 12.97m in SL-02-31. Although not specifically targeted in the drill program, significant lithium (spodumene) mineralization was also encountered at the South Aubry zone including: 1.460% Li2O over 4.25m including 2.389% Li2O over 1.80m in SL-02-17, 0.757% Li2O over 13.30m including 0.976% Li2O over 4.60m in SL-02-20, 0.648% Li2O over 10.36m including 1.368% Li2O over 2.15m in SL-02-21, and 0.390% Li2O over 7.07m including 1.401% Li2O over 2.92m in SL-02-22.

Jan 22, 2018 (Therese Pettigrew) - Diamond drilling also extended the strike of the South Aubry pegmatite, giving it an indicated strike length of 320 m. The main portion of the pegmatite has a true thickness on the order of 15 m, and it remains open to the north, south, and down-dip to the east. Tantalum grades and fractionation appear to be increasing in the southern portions of the dyke, with the highest grades returned from DDH SL02-24. This hole, the southernmost on the South Aubry, averaged 0.018% Ta2O5 over 4.05 m. Weighted averages from all of the South Aubry drill intercepts produce an overall grade of 0.013% Ta2O5. Two holes, SL02-17 and 18, were drilled on the trench SA-5 pegmatite between the North and South Aubry zones. Both holes intersected several dykes, grading up to 0.011% Ta2O5 over 5.54 m and 0.019% Ta2O5 over 6.25 m (AFRI 52I08NW2004). DDH SA-171-5 intersected 24.0 m of continuous spodumene mineralization with an average lithium grade of 0.82% Li2O and containing a number of high grade zones including 2.00 m at 2.42% Li2O. DDH SA-17-11 intersected 21.0 m of continuous spodumene mineralization with an average grade of 0.50% Li2O (Ardiden press release Dec 19, 2017). DDH SL-16-68 returned 1.64% Li2O over 8.06 m. DDH SL-69 returned 1.07% Li2O over 7.8 m (Assessment report 20000016178).

Mineral Record Details

References

Map - Crescent Lake area, Thunder Bay District

Publication Number: M2100 Date: 1997

Author: Pye E.G.

Publisher Name: Ontario Dept. of Mines

Location:

MonoMap - Geology of the Crescent Lake area, District of Thunder Bay

Publication Number: R055 Page: 49  Date: 1968

Author: Pye E.G.

Publisher Name: Ontario Dept. of Mines

Location:

Mono - Pegmatite mineral resources of Ontario

Publication Number: IMR021 Page: 48  Date: 1997

Author: Hewitt D.F.

Publisher Name: Ontario Dept. of Mines

Location:

Publication - Technical Report on the Seymour Lake Property

Publication Number: 2010 NI 43-101 Date: 2010

Author: Rees, M.

Publisher Name: Linear Metals Corp.

Location: SEDAR, filed under Stockport Exploration

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