DISCOVERY CASE HISTORY OF THE PYRAMID ORE BODIES PINE POINT, NORTHWEST TERRITORIES, CANADA

In the fall of 1965 a geophysical exploration program, in the Pine Point area, Northwest Territories, Canada, revealed indications which led to the discovery of 11.2 million tons of ore grading 11.7 percent combined lead and zinc in two separate ore bodies. The ore bodies are relatively flat‐lying although irregular in plan and section. They lie in limestones and dolomites, some reefoidal, of Middle Devonian age and are generally conformable to these sea sediments. The basic discoveries were effected by a time‐domain, induced‐polarization survey. A subsequent gravity survey proved to be of considerable value in guiding the extensive drilling program which followed and in predicting the amount of ore to be expected in each body. Despite a high marcasite content, the ore bodies did not respond appreciably to electromagnetic induction methods. This is attributed to the mode of distribution of the various sulfide minerals in the deposits.