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Winspear receives additional results from Camsell Lake
Winspear Resources Ltd WSP
Shares issued 33,721,333 Jan 15 close $3.18
Fri 15 Jan 99 News Release
Mr. Randy Turner reports
Winspear Resources Ltd. has received additional results from its evaluation
of the diamonds recovered from processing two 100-tonne mini-bulk samples
that were obtained from the subcrop of the NW dyke, Snap Lake area, Camsell
Lake property, Northwest Territories. This property, which is 220
kilometres northeast of Yellowknife, is operated through a joint venture in
which Winspear has 67.7 per cent interest and is operator.
The NW dyke at Snap Lake was discovered by diamond drilling in 1997 when it
was intersected by 13 drill holes. Because of encouraging results obtained
from caustic fusion analyses for microdiamonds in these drill core
intersections, two 100-tonne samples were obtained from the dyke in the
spring of 1998 and processed in the Kennecott plant in Yellowknife. Cleaned
diamonds recovered from the plant weigh 226.72 carats, which establishes
the grade of the kimberlite sample at 1.14 carats/tonne. Three independent
diamantaires in Antwerp valued these diamonds at $301 (U.S.)/carat.
NEW RESULTS
Coarse Diamond Size Distribution
The value of kimberlite comprising the mini-bulk sample from the NW dyke is
enhanced by the presence of three large gem-quality diamonds weighing
10.82, 8.42, and 6.04 carats, respectively, two of which were recovered
from Pit 2 and one from Pit 1. Furthermore, an additional 22 diamonds were
recovered that weigh between 1.01 and 5.00 carats. Seven of these 22
diamonds were recovered from the Pit 1 sample and the remaining 15 were
recovered from the Pit 2 sample. The combined weight of the 25 diamonds
that weigh more than one carat is 67.72 carats; this represents 29.8 per
cent by weight of the total parcel. These weights were established in the
process of obtaining a detailed study of the diamonds by Dr. Malcolm E.
McCallum, results of which are reported below. The three large diamonds
contribute approximately 10 per cent of the weight and about 75 per cent of
the value of the total parcel. The balance of the parcel exclusive of the
three large stones is valued at $83.26 (U.S.)/carat. This distribution of
values is in keeping with results that would be expected from an occurrence
with a significant population of large, high-value gem stones.
Several noteworthy aspects of these 200 tonne mini-bulk sample results are:
Although this mini-bulk sample is regarded as too small to accurately
predict either value or grade for the kimberlite comprising the NW dyke, it
is important to note that the kimberlite does carry large gem-quality
diamonds.
The diamond population obtained from the mini-bulk sample for stones
greater than one carat in size is not large enough to be statistically
relevant. However, the average diamond size of recovered diamonds less than
one carat is consistent with that of a producing kimberlite with a high
average stone size and a bottom cut-off similar to that used in the
Kennecott plant.
The three large diamonds recovered from the mini-bulk sample contribute
25.28 carats or approximately 10 per cent of the total weight of diamonds
recovered. The value of the remaining diamonds is $93.26 (U.S.)/carat
(approximately $122/Canadian/carat) which equates to a value of
approximately $94.90 (U.S.)/tonne (about $140 Canadian/tonne). MRDI Canada,
a division of H.A. Simons Ltd., has estimated in a scoping study on
potential mineability of the NW dyke kimberlite that total operating costs
(mining, processing, general and administration) of a combined open pit
underground mine based on known characteristics of the NW dyke, assuming a
10-year mine life and 1,000 tonnes/day production rate, is $86.41
Canadian/tonne (approximately $59 (U.S.)/tonne), Winspear notes that the
smaller diamonds alone would more than cover the estimated operating costs.
As the 200 tonne mini-bulk sample contains relatively large, high quality
gems, the NW dyke may differ significantly from most other kimberlites
reported to date from the NWT in that a significant portion of its value
may be contained in large, high-value diamonds.
Diamonds to be recovered from the larger 6,000 tonne bulk sample planned
for the spring of 1999 will more accurately reflect grade and value
characteristics of kimberlite from the NW dyke. Geostatistical evaluation
of diamonds recovered from the 200 tonne mini-bulk sample points to the
likelihood that larger diamonds will be recovered from this bulk sample.
Although the quality of these larger diamonds cannot be predicted by
geostatistical techniques, the fact that the three largest diamonds
recovered from the NW dyke are good gem diamonds suggests that more large
gems will be recovered from a larger bulk sample.
Diamond Study
The parcel of diamonds recovered from the two 100 tonne kimberlite samples
obtained from the NW dyke comprises 1,387 diamonds. A study of 1,291
diamonds from this parcel was undertaken by Dr. Malcolm E. McCallum, a
recognized international expert with considerable experience in this field.
The remaining 96 diamonds that were not studied in detail represent the
smallest screen-size of diamonds recovered. Because plant recovery in this
small size range is inefficient, these diamonds were considered to be
unrepresentative of the size class and were omitted from the study.
Although the small size of this diamond parcel precludes rigorous
statistical treatment, Dr. McCallum considers that the observed
distribution of the physical properties is statistically relevant. The main
conclusions of his report are as follows:
The various physical characteristics exhibited by the three large gem
diamonds (10.82, 8.42, and 6.04 carats) recovered from the kimberlite are
completely consistent with those observed in smaller stones from all size
fractions.
There is a strong correlation of morphological characteristics between
diamonds recovered from each of the two sample sites.
The number of large stones recovered from this sample is unusual but not
unprecedented. Based on the high concentration of large diamond fragments
in the +9 and +11 size fractions, as well as evaluation of size-frequency
distribution curves, preferential breakage of larger, poorer quality stones
appears likely to have occurred either by late magmatic or induced
processes.
Dr. McCallum subsequently has commented that some of the overgrowth
features present on many diamonds in this population have not been reported
from other localities in NWT and may provide a unique signature for diamond
parcels from the NW dyke at Snap Lake. Winspear notes that kimberlite of
the NW dyke is also unusual in its intrusive form and compositional
characteristics of its indicator minerals.
Summary
Significant points of the information presented above are as follows:
Diamonds recovered from the mini-bulk samples have size/frequency
distribution characteristics consistent with a coarse diamond population.
Although the number of large diamonds recovered from the mini-bulk sample
is too few to be statistically significant, large gem-quality diamonds do
occur in kimberlite from the NW dyke.
Removing the value represented by the three largest diamonds from the value
of the total parcel of recovered diamonds results in an average value per
tonne that is about 60 per cent higher than total estimated operating costs
for a combined open-pit/underground mining operation.
Results have been received for caustic fusion analyses of 500 kilograms of
kimberlite representative of the mini-bulk samples and from kimberlite
intersections obtained from the 1998 drill programs. These results will be
released shortly when preliminary evaluation of them has been completed.
Winspear regards these results as encouraging and supportive of the
recently announced 1999 program on the property estimated to cost about
$12-million. This program, which will mainly comprise bulk sampling and
diamond drilling, will get under way as soon as winter conditions permit.
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