Process changing with the times

I would like to thank you for maintaining an excellent flow of exploration news during a prolonged period of upheaval. However, I feel your newspaper could be further improved by more careful editing of some of the articles.

A case in point is the story on changing exploration methods (“Exploration methods have seen great changes in past 25 years,” T.N.M., Mar. 30/92). In the paragraph that deals with heavy mineral geochemistry of glacial overburden via reverse circulation drilling, the author claims that “tens of thousands of RC holes were drilled throughout Canada from about 1970 to the 1980s” and that “very little, if any, of this work is going on at present.” He grudgingly acknowledges that “the fundamental approach seems sound enough” and there have been a “a couple” of successes but argues that “the vagaries of glacial processes have greatly complicated the useful interpretation of the heavy mineral results.”

If the author had taken the time to discuss this topic with researchers and contractors who are active in RC drilling and heavy metal geochemistry, he could have reported newsworthy facts instead of recession opinions. Only 18,000 holes have been drilled, not “tens of thousands,” and “a couple” of successes include the major Casa Berardi gold deposits and Collins Bay and Eagle Point uranium deposits. RC project expenditures total about $30 million, similar to gross exploration expenditures for northern Saskatchewan in 1991 (hardly a banner year).

More often than not, “glacial variation” has been the scapegoat for inexperienced geologists who foolishly followed up high gold assays caused by nuggets instead of searching for more moderate anomalies caused by fine-grained gold. Glacial processes are no more vicarious than other geological processes; experienced geologists recognize these variations and plan their work programs accordingly.

RC drilling is basically a grassroots exploration tool and its current decline, like that of surface geophysics and diamond drilling, is directly related to the short-sighted (for Canada) decline in grassroots exploration, particularly for gold.

However, instead of rolling over and dying, RC drilling and heavy mineral geochemistry have been adapting –like The Northern Miner — to changing market conditions. In particular, they have been revived for base metal exploration in Canada and are being applied in Carlin-type gold situations in unglaciated terrains.

Stuart Averill

President

Overburden Drilling

Management Ltd.

Nepean, Ont.