Artemisia proves low-grade with lack of big stones (August 05, 2002)

The results of a mini-bulk drill sample from Artemisia, one of the promising kimberlites Ashton Mining of Canada (ACA-T) discovered last fall in the Coronation Gulf region of Nunavut, indicate that the pipe-like body does not carry enough commercial-size stones to be economic.

An 11-tonne sample of kimberlite collected from seven core holes returned a total of 1.176 carats of diamonds larger than 0.8 mm, using a square aperture screen. The grade of the sample works out to be 0.107 carat per tonne or 10.69 carats per 100 tonnes. The largest stone recovered was a colourless aggregate crystal weighing just 0.08 carat. No further work is planned on Artemisia.

While the latest results are disappointing, they are in line with an earlier, 1.2-tonne kimberlite sample taken last fall at surface. That sample had an implied grade of 0.17 carat per tonne.

Artemisia had been considered a promising find. Ashton’s field crew discovered the outcropping Artemisia while investigating the source of an indicator mineral train and diamond-bearing kimberlite float on the Kim property. Kim is one of several properties held under the Slave Regional joint venture, in which Ashton has an 89.4% interest and Pure Gold Minerals (PUG-T), the remainder.

The discovery hole at the centre of the Artemisia occurrence returned 812 microdiamonds and 86 macros from 246 kg of core. (A macro is defined here as exceeding 0.5 mm in one dimension.) An additional 85.5 kg of material sampled from outcropping kimberlite and talus yielded 309 micros and 34 macros. Measuring 250 by 150 metres, or about 3 hectares, at surface, Artemisia has been drilled to a depth of 225 metres and consists of homogenous kimberlite.

Meanwhile, surface samples from a second outcropping kimberlite on the Kim property have proved diamondiferous. In the spring, a field crew investigating a 100-metre-diameter magnetic anomaly, 2.5 km southwest of Artemisia, discovered the Thrift kimberlite on the shore of a small lake. Samples of hypabyssal kimberlite taken from float and outcrop, for a total of 100.8 kg, yielded only nine micros.

A summer program of prospecting and heavy mineral sampling is evaluating potential targets on the joint venture’s Kim, Eokuk, Ric and James River properties.