TORONTO (miningweekly.com) – Explorer CanAlaska Uranium has gained a multimillion-dollar endorsement from the world’s largest crystallised-carbon producer De Beers Group of Companies, after the partners entered into an option-participation agreement for expenditures of up to C$20.4-million on kimberlite-style targets staked by CanAlaska in the Northwestern Athabasca basin of Saskatchewan.

Under the agreement, announced Wednesday, affiliate De Beers Canada would spend millions of dollars in search of diamonds in northern Saskatchewan, pursuing 75 kimberlite-style targets developed from a 2011 high-resolution airborne geophysical survey carried out on behalf of the Saskatchewan Geological Survey.

The airborne magnetic survey, flown at 400 m line spacing, had revealed a series of distinct magnetic anomalies northeast of the Carswell structure and close to the large crustal suture related to the Grease River Fault zone.

The partners advised that the Saskatchewan government's Kimberlite Indicator Minerals (KIM) sampling programme had previously reached close to the Carswell structure, but that the northern-most samples were south-east of the down-ice trend from these magnetic anomalies.

"These 75 circular targets fit all the geological and geophysical criteria of kimberlites. The location of the targets within a thick sequence of crustal rocks and their clustering around major structural features provides a compelling target for CanAlaska and De Beers," stated CanAlaska president Peter Dasler.

Vancouver-based CanAlaska had staked its first claim on the 17 400 ha site in 2012, after using data from the study to identify several kimberlite targets in the area. Kimberlite is an igneous rock best known for sometimes containing diamonds. It was named after the town of Kimberley, in South Africa.

The partners advised in a joint statement that little exploration work had been conducted in this area of the Athabasca basin, where some of the world’s highest-grade uranium deposits were found.

Previously, the sampling for KIM in the Fort McMurray area of Alberta, had showed a grouping of KIM dominated by chromite, with some pyrope and eclogitic garnets. These appeared to be down-ice from the kimberlite-style targets identified within the Athabasca sandstone in north-western Athabasca.

Basement rocks below the Athabasca sandstone formed part of the Rae province, north of Athabasca in the Nunavut Territory, with a projected lithospheric thickness of more than 150 km, within the diamond stability field. Rae province-hosted diamondiferous kimberlites had only been briefly investigated in the past.

Under the agreement, De Beers would invest up to C$20.4-million in four stages, spread over seven years. Each investment would earn De Beers a progressively larger stake in the project, up to a total of 90%.

Should it choose to proceed, De Beers would undertake a detailed airborne survey, sample for diamond indicators near the targets and then drill-test prioritised targets. CanAlaska had the option to participate as a joint-venture partner once De Beers had earned its 70% interest.

"Our alliance with De Beers will allow rapid first pass evaluation, and we look forward to the ability to participate with De Beers as a partner as the project grows," Dasler added.