Otish rocks diamondiferous (December 24, 2001)

Vancouver — Diamond counts have determined the favourable nature of two kimberlitic bodies in Quebec’s Otish Mountains.

Ashton Mining of Canada (ACA-T) discovered the bodies while drill-testing four geophysical anomalies earlier this year. The first body, dubbed Renard 1, returned 54 microdiamonds (measuring greater than 0.1 mm but less than 0.5 mm in one dimension) and five macrodiamonds (greater than 0.5 mm in one dimension) from a 205.8-kg sample.

Situated 1 km south of the first geophysical target, a second magnetic anomaly, Renard 2, yielded a similar ultramafic igneous rock some 18 metres under overburden to a down-hole depth of 101 metres. Renard 2 yielded 116 microdiamonds and 29 macros from a 163.1-kg sample. The largest stone measured 1.63 by 1.58 by 0.53 mm.

The Renard 1 sample is described as a hypabyssal facies rock, while Renard 2 contains both hypabyssal and diatreme facies rocks. Both samples show transitional characteristics between kimberlites and melnoites. The latter is a rock type derived from similar depths as kimberlites but differing slightly in the chemical composition of its groundmass minerals.

Two other anomalies tested during the first round program failed to return any ultramafic material.

Based on the promising results, Ashton will launch an exploration program in north-central Quebec next year. The objective will be to trace unexplained mineral indicator trains, as well as delineate drilling over the Renard 2 body.

Ashton holds more than 1,760 sq. km in the area in a joint venture with government-owned Soquem. Since 1996, the pair has been searching for diamonds in the northern Quebec portion of the Superior Craton. After carrying out reconnaissance programs of heavy mineral sampling and airborne magnetic surveys on more than 450,000 sq. km of prospective terrain, the partners staked 1,000 sq. km of key ground in two areas of Quebec. Ashton zeroed in on the Otish Mountains region.