Forgotten Thelon attracts attention

Vancouver — Sharing many similarities with the better-known Athabasca basin in northern Saskatchewan, the Thelon basin, situated on border of the Northwest Territories and Nunavut, is enjoying an exploration renaissance testing its unconformity-type uranium mineralization potential.

The Thelon had seen a significant amount of previous exploration, particularly during the uranium boom of the 1970s and 1980s, but largely slid from the plate when the metal price slumped and high-grade deposits were discovered in the Athabasca basin, several hundred kilometres south.

Although the geologically similar basins are of similar size, known uranium resources in the Thelon are less than 10% of those in the Athabasca.

Exploration programs conducted by Urangesellschaft Canada (now part of Cogema Resources), Cameco (CCO-T, CCJ-N), PNC Canada Exploration (a subsidiary of the Japanese company Power Reactor and Nuclear Fuel Development Corp.), Gulf Minerals and others led to the discovery of a few significant uranium occurrences, the largest being Kiggavik.

Cogema’s Kiggavik deposit, located about 80 km west of Baker Lake in the northeastern Thelon basin, hosts a historic resource of about 40 million contained pounds U3O8 in mineralization averaging about 0.4% to 0.5% U3O8. The unconformity-type deposit was extensively delineated, including environmental studies and modelling of an open pit, but has yet to see development.

Titan Uranium (TUE-V, TUEFF-O) is one of the latest explorers gearing up to test its mineral leases in the Thelon. Reportedly one of only two companies with drill permits in hand from the Kivalliq Inuit Association and Indian and Northern Affairs Canada, the company plans a 26-hole, 3,000-metre program this summer, scheduled to begin in mid-July, after the caribou calving season is over.

Titan’s eight leases cover about 680 sq. km on the northeastern margin of the basin and are situated about 150 km northwest of Baker Lake. The ground covers the unconformable contact between the Thelon sandstones and the underlying Amer Group metasediments, with most of the targets at shallow depths.

The project area was previously explored by Westmin Resources and its joint-venture partner CEGB Exploration Canada (now part of Cameco). Multiple geochemical and geophysical anomalies were delineated — many to drill-stage — but slumping uranium prices saw them go untested. About $5.5 million was spent on the program from 1976 to 1984.

Drill targets are typically spotted at the head of uraniferous boulder trains in the tundra environment. Titan anticipates initially drilling vertical holes to an average depth of around 80 metres.

Boomerang project

Across the basin, to its southwest margin, Uravan Minerals (UVN-V, URVNF-O) and JV partner Cameco plan a summer drill program on the Boomerang uranium project. The duo will target electromagnetic (EM) anomalies within large conductive trends, looking to test zones where favourable graphite-bearing metasedimentary basement rocks underlie the Thelon sandstone cover.

A 1983 drill program at Boomerang intersected a 0.5-metre section grading 0.50 % U3O8, 22.4 grams gold per tonne and 12.3 grams silver per tonne in strongly altered Thelon sandstone at the faulted unconformity.

Some of the other entrants in the Thelon uranium hunt include:

* Bayswater Ventures (BVE-V, BVEVF-O) and JV partner Strongbow Exploration (SBW-V, SBWFF-O) hold a large land position on projects in the north and south Thelon, with Pathfinder Resources (phr-v, pfdff-o) entering the mix through a recent agreement to merge with Baysfield;

* Yankee Hat Minerals (KHT-V, YKHTF-O), which optioned 360 sq. km of prospecting permits in the southern section of the basin in mid-2005;

* Diamonds North Resources (DDN-V, DNORF-O), which has a significant position of more than 4,800 sq. km in the Thelon basin that is under option to Pathfinder, and has recently reviewed plans to spin out a separate company to hold its uranium assets;

* Majescor Resources (MAJ-V) is earning an 80% interest on prospective uranium claims in the eastern area of the basin from De Beers;

* Eastmain Resources (ER-T, EANRF-O) received exploration permits for its landholdings in the northern and southeastern portions of the basin — which it reports are held by its 50%-owned Ruby Hill Exploration — earlier this year. Subsequently, Western Uranium (wuc-v) announced it had acquired the privately held Ruby Hill Exploration and its Thelon assets; and

* Ur-Energy (URE-T, UREGF-O) holds three projects, all in the southwestern portion of the Thelon, which yielded positive geophysical results earlier this year.

Record uranium prices are spurring an increasing number of explorers to re-evaluate the Thelon basin, but not without some hurdles, as the region is a bit more remote than the Athabasca basin. Exploration and drill permitting has proven somewhat onerous with many levels to deal with and long lead times for planned programs. Nevertheless, eyes will be watching the modest drill programs planned for this summer to see if the basin shows signs of delivering the goods.