Northern Saskatchewan prime exploration area

The downward trend in exploration spending in Saskatchewan, apparent since 1988, appears to have flattened and 1992 expenditures are expected to match those for 1991, Saskatchewan Energy and Mines reports.

Exploration expenditures in northern Saskatchewan in 1991 totalled $24 million; in 1990 they were $32 million. Major minerals sought are gold, base metals, uranium and diamonds.

Gold exploration and development activity declined in 1991 and only about one dozen companies are now active compared with more than 60 in 1988. Most work continues to be concentrated in the La Ronge and Glennie Domains. Mining in the Star Lake gold camp has stopped; the Jolu and Jasper mines have closed on schedule and the Star Lake mill processed the last Jasper mine ore in December.

At the Jolu mine, the last ore was extracted in May, 1991, and milling finished in August. Despite its less than 3-year life span, the mine was extremely successful, producing 203,301 oz. gold from 520,000 tons of ore grading 0.4 oz. gold per ton gold at a cost of US$150.43 per oz. The La Ronge gold belt area has shown resilience to the decline in exploration dollars. Joint venture operator Cameco (TSE) continued exploration at Contact Lake this winter after a year of inactivity on the property. A 42,500-ft. drill program is attempting to add to the minable reserves of 1.5 million tons grading 0.24 oz. gold in the BK 1 and 2 zones, by testing the BK 3 and “Upper Structure” zones.

A preliminary feasibility study has proposed a 770 tpd mine/mill complex with capital costs of $39 million and production costs of $249.82 per oz. The project, which lies within the mineral exploration zone of the La Ronge Provincial Park, has received all necessary approvals for development. Elsewhere in the La Ronge gold belt, Uranerz Exploration and Mining undertook an expanded grassroots program focusing on the Kruger Lake pluton. Homestake Mineral Development also carried out grassroots exploration, in the southern part of the belt, on several properties optioned from Durama Enterprises Ltd. Alligator Resources Ltd., a Saskatoon-based prospecting syndicate, found the “Broken Hammer Vein” on CBS 6120 northeast of Lower Waddy Lake. The structurally controlled vein has returned values of up to 21 oz. gold. In the Glennie Domain, Claude Resources (TSE) began construction of the Seabee mill in earnest in April, 1991, achieved start up in November, and poured the first gold bar of about 1,100 oz. in early December. Production through December to February averaged about 4,500 oz. per month. The mill has a startup capacity of 440 tpd and uses a conventional carbon-in-pulp system. An estimated annual production of 52,000 oz. will be supported at Seabee by reserves estimated to be in excess of 1.1 million tons grading 0.4 oz. On the exploration side, Claude announced the discovery of the 161 zone at Seabee and obtained encouraging results in the Santoy Lake area, 5 miles due east of the mine site. The 161 zone is located about 660 ft. southwest and along strike of the geologically similar No. 5 zone, and consists of multiple sub-parallel structures identified over a length of 500 ft. and to a depth of 600 ft. Plans are to integrate future work on the 161 zone with the current underground development of zones 2 and 5.

At Santoy Lake, Claude and Manchester Resources (ASE) have reported the discovery of several gold showings and a 3,000-ft. drill program is planned to test favorable results from a trenching and bulk-sampling program. The zone 2 showing was reported to be highlighted by a folded portion averaging 0.56 oz. over about 27 ft.

Nine miles south of these showings, American Ore (ASE) and Leeward Capital (VSE) completed a 13-hole, 5,000-ft. drilling program along a portion of the Georges Lake fault. Showings adjacent to the structure contain folded quartz veins with abundant visible gold in places. All drill holes encountered quartz veining, with sulphide mineralization and rare visible gold. On the base metal side, most exploration activity has been confined to the sub-Phanerozoic area south and southwest of Flin Flon. The “Norite” project north of Stony Rapids, designed to find a commercial nickel-copper-cobalt deposit, is an exception.

Billiton Metals Canada completed a $17.5 million purchase of the Trimin Resources (TSE) 32.9% interest in the McIlvenna Bay zinc-copper deposit near Hanson Lake. The deposit, in which Cameco owns the other 67.1% interest, is an advanced exploration project and published reserves to 1989 are 11.8 million tons grading 1% copper and 5.4% zinc.

These reserves, in three lenses, are based on 54-holes only and do not include any new reserves defined by seven 1990 holes or the 1991 drill program. Cameco believes “the deposit remains open down plunge, with good potential for finding additional lenses at depth along this mineralized stratigraphic horizon.” The project is expected to be inactive in 1992. In the sub-Phanerozoic area to the west of Hanson Lake, Granges (TSE) completed another 8,500-ft. diamond drill exploration program on the Bigstone deposit in February, 1991. Reserves published in 1985 of 1.6 million tons grading 2.8% copper and 375,000 tons grading 11.2% zinc are based on about 69,000 ft. of drilling. No updated reserves have been released. The “Norite” nickel-copper joint venture project of Consolidated Pine Channel Gold (VSE) and Noranda Exploration is located just north of Stony Rapids in the Tantato Domain in high-grade metamorphic, mafic and ultramafic rocks, which have been called “norites.” They host, among other prospects, the low-grade Axis Lake deposit known to contain 3.7 million tons of 0.6% nickel, 0.6% copper and 0.15% cobalt. Five targets were drilled in the fall of 1991 and only low-grade mineralization was encountered.

Saskatchewan remains at the focus of uranium production and exploration in Canada. Output, some two-thirds of Canadian and one-fifth of western world production, is estimated at around 6.9 million kg in 1991, although only the Key Lake mine operated at capacity. The Rabbit Lake mill remained shut down until August and Cluff Lake operated at half of capacity.

Some dozen companies are still actively exploring in the Athabasca Basin. Although no significant discoveries were reported, six major new mining projects were in various stages of advancement.

At Rabbit Lake, construction of the Eagle Point test mine began last June with full production scheduled for 1993. The steeply dipping ore zones are being evaluated by major drill programs from the 370-ft. and 600-ft. levels. At Cigar Lake, a test-mining project in which two vertical 5-ft. bore holes were drilled upward through the deposit from the 1,575-ft. level was completed in October. About 55 tons of uranium ore grading 14.4% were extracted. Further tests of the remote mining method, which will likely be necessitated by new proposed limits to radiation exposure, are planned in 1992 and environmental impact and feasibility studies in 1993. Together with Cigar Lake, expansion of the Dominique-Janine open pit at Cluff Lake and development of an underground mine at Midwest Lake and of open pits at McClean Lake, are all projects scheduled for immediate review by the newly formed federal-provincial uranium review panel.

Major players in diamond exploration in the province are Monopros, Cameco, Uranerz and Claude.

In late July, 1989, joint venture partners Uranerz (the operator) and Cameco drill-tested seven magnetic anomalies in the Fort a la Corne area 36 miles east of Prince Albert.

In 1990, a drilling program of 15 holes on several pipes recovered almost 16.5 tons of kimberlite.

Last September, the joint venture announced that additional diamonds had been recovered during their recently concluded 1991 exploration program. A total of 205 tons of kimberlite was obtained by large-diameter drilling beneath the 330-ft.-thick overburden.

Diamonds recovered in 1991 range up to 0.6 carats. The larger stones or macrodiamonds appear to be of gem quality. A total of 160 macrodiamonds have been recovered to date from 15 kimberlite pipes. The average weight per stone is 0.04 carats.

Andrew Gracie and Pamela Schwann are resident geologists with Saskatchewan Energy and Mines.