Winspear releases Snap Lake estimates

The total in situ “global tonnage” resource for the NW Snap Lake kimberlite dyke is estimated at 23.4 million tonnes, with an average vertical thickness of 2.44 metres.

Snap Lake is part of the Camsell Lake project, situated 220 km northeast of Yellowknife, N.W.T., while Winspear Resources (WSP-V) is the operator and holds a 67.76% interest. Aber Resources (ABZ-T) holds the remaining 32.24% but is currently involved in a legal dispute with Winspear over its right to participate in this year’s exploration program and could face a dilution of 16%.

The NW dyke subcrops on the northwestern peninsula and dips 11-15 to the east beneath Snap Lake. Drilling indicates that the dyke extends 2 km in a northerly trending direction and 2.5 km downdip. The dyke remains open and thickens to the north and east but becomes thinner to the south and southeast.

The NW dyke appears to be a continuous sheet comprising a single phase of kimberlite that is dominated by hypabyssal (macrocrystic) material. Local areas occur within the dyke where an abundance of country rock fragments define the material as kimberlite breccia. Winspear states that this variety of kimberlite is uncommon and generally thin, and that it normally occurs with thicker sections of hypabyssal kimberlite.

The detailed tonnage estimate was prepared by MRDI Canada, a division of H.A. Simons, based on a total of 180 drill hole intersections completed from 1997 through 1999. Separate tonnage estimates were made for those areas within which the kimberlite dyke exceeds 1 metre and 2 metres of thickness (23.2 million tonnes at a 2.76-metre vertical thickness and 19.2 million tonnes at 3 metres, respectively) to illustrate the relative uniformity of the dyke. The true thickness is estimated to be at least 90% of the vertical thickness.

The global tonnage estimate also includes 1.5 million tonnes of internal waste. This refers to host rock material greater than 10 cm thick that occurs within the kimberlite intersection. A re-evaluation may result in some of this material being re-classified as xenoliths.

MRDI has further defined 8.5 million tonnes of hypabyssal kimberlite and kimberlite breccia averaging 2.69 metres thickness to levels acceptable for feasibility study purposes. This is based on 140 drill hole intercepts exceeding 1 metre of thickness. The 2-metre-plus portion of the dyke totals 7.8 million tonnes at an average thickness of 2.79 metres, based on 132 holes.

This surpasses Winspear’s stated objective of defining a resource of 5 million tonnes for the basis of a feasibility study.

Upon completion of microdiamond analysis of the 100-plus drill hole intersections carried out this past spring, Winspear hopes to predict macrodiamond grades for the tonnage estimates.

Diamond grades and values for the second half of a 6,000-tonne surface bulk sample collected from pit 3 are expected by month’s end. The first 3,000 tonnes of sample taken from pit 4 yielded 5,542.27 carats of cleaned diamonds for an indicated grade of 1.845 carats per tonne. The stones were determined to be worth an average of US$98.42 per carat, which translates into an implied value of US$181.58 per tonne.