Monopros to bulk-sample AK pipes

Monopros, the exploration arm of De Beers Consolidated Mines (DBRS-Q), will proceed with a bulk-sampling program this winter on the AK property in the Northwest Territories.

Monopros has the right to earn up to a 60% interest in the AK and CJ properties, which are currently held 90% by Mountain Province Mining (MPV-V) and 10% by Camphor Ventures (CFV-V).

Since entering into the joint venture, Monopros has discovered three diamondiferous pipes on the AK property — Tesla, Tuzo and Hearne — all of which are within 1.1 km of the original 5034 discovery.

This past winter, Monopros collected 50-tonne mini-bulk drill samples from each of the pipes to determine preliminary grades and valuations. Though the recovered parcels of diamonds are considered by De Beers to be too small to provide reliable estimates of average diamond values, the major used these values, together with the previously reported micro and macrodiamond results, to model a range of possible diamond values per carat at a commercial cutoff of 1.5 mm.

Available data indicate the following preliminary estimates of grade and value per carat:

* the 5034 pipe is estimated to have a grade of 1.6 carats per tonne and a diamond value of US$51 per carat, for an implied value of US$82 per tonne;

* the Hearne pipe grades 2.33 carats at US$44 per carat, or US$103 per tonne; * Tuzo has an indicated grade of 2.2 carats per tonne at US$68 per carat, equivalent to a value of US$150 per tonne; and

* the Tesla pipe grades 0.37 carat at US$96 per carat, equivalent to US$36 per tonne.

The original 5034 kimberlite is estimated by De Beers to contain a 15-million-tonne resource down to a depth of 300 metres. While no additional resource estimates have been provided for the three other pipes, the 1998 annual report for Mountain Province suggests that preliminary estimates of the four pipes total about 40 million tonnes of kimberlite.

In a report, David James, a mining analyst with Canaccord Capital, writes that the Hearne pipe is estimated to contain a resource of 10 million tonnes to a projected depth of 300 metres; the Tuzo holds 10 million tonnes as well; and the smaller Tesla pipe contains 5 million tonnes.

Planning for the large-diameter bulk-sampling program is at an advanced stage, and applications for all permits have been submitted.

De Beers hopes to extract at least 500 tonnes of kimberlite from each pipe. Samples of this size are expected to produce between 1,000 and 2,000 carats, using a bottom cutoff of 1 mm, for the 5034, Hearne and Tuzo pipes, and a lesser quantity for the Tesla pipe.

Monopros may move a dense media separation plant on to the site to treat the bulk samples.