Kennecott Canada Inc. can acquire a 60 percent interest in the Candle Lake project from War Eagle Mining Company and Great Western Gold Corporation by spending $8 million over five years for exploration and development. In 1997, Kennecott planned to collect a bulk sample from kimberlite #29/30 weighing approximately 45 t with four reverse circulation large diameter drill holes. From previous drilling and geophysical surveys, #29/30 is estimated to contain 70 million t of kimberlite. The company planned to drill two holes in the thickest part and two others near DDH.CL.95-01 located some 250 m away. DDH.CL.95-01, drilled in the northwest part of kimberlite #29/30, recovered a total of 46 micro and macro diamonds per 100 kg, which is among the highest counts reported from Saskatchewan. Proton microprobe analyses of pyropes and chromites from this kimberlite show that it has sampled deep Archean lithosphere and is therefore highly prospective for diamonds. Two twelve inch diameter, reverse circulation drill holes succeeded in reaching the top of the kimberlite and were cased. Only dust was recovered when drilling of the kimberlite itself started. Because this meant that the threat of fracturing diamonds was too high, the drilling was stopped immediately. A large drill, that has been successful in kimberlite drilling elsewhere, will be used to complete the 22.7 t bulk test from the two cased holes as soon as field conditions permit.
The "banana" shaped, glacially eroded kimberlite, #C28, lies beneath a minimum of 102 m of overburden. The kimberlite has a maximum thickness of around 140 m, the base is shaped like a very flat "v" in long section and a cone in cross-section. The top is dome shaped; the sides dip inward at 45§ in cross-section. It is postulated that the kimberlite represents a "spatter cone" with a top removed by erosion. The kimberlite lacks distinct bedding, but exhibits gradational variations in grain size over a few metres.
The company has tested kimberlite #C28 with eight diamond drill holes and processed 1927.5 kg of #C28 kimberlite. All holes contained diamonds. A total of 192 were recovered for an average of 10 diamonds larger than 0.15 mm/100 kg (Table 5). If results from the bulk test on kimberlite #29/30 are positive, the company may proceed to take a bulk sample from kimberlite #28.
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