Winspear reports microdiamond results from Snap Lake
Winspear Resources Ltd WSP
Shares issued 33,721,333 Jan 25 close $3.72
Tue 26 Jan 99 News Release
Mr. Randy Turner reports
Winspear has received microdiamond results from caustic fusion analyses of
kimberlite drill core intersections obtained during the 1998 winter/spring
and summer/fall seasons from the Snap Lake area of the Camsell Lake
property, Northwest Territories in which Winspear has 67.7 per cent
interest and is operator. Microdiamond results have also been received from
approximately 250 kilograms of kimberlite representative of each of the two
100 tonne kimberlite samples obtained from the NW dyke. These results are
subject to continuing evaluation by MRDI Canada, a division of H.A. Simons
Ltd.
Microdiamond results are being collected by Winspear to form a data base
from which it is hoped to derive a macrograde predictive model for areas of
the NW dyke down-dip from the subcrop. Interpretation of this microdiamond
data is in progress; for this reason, no estimate of macrodiamond grade is
presented. Rather, these data are presented as the best tool presently
available by which to gauge the uniformity of diamond distribution in the
NW dyke.
Results reported here and obtained by Lakefield Research differ from
previous results because of changes in analytical procedures and additional
procedural requests made by Winspear. Lakefield now recovers diamonds down
to as small as 0.1 millimetres in order to improve the recovery efficiency
of diamonds greater than 0.15 mm. Consequently, some microdiamonds are now
recovered that previously would have been lost during analysis.
Furthermore, Winspear has requested that Lakefield sieve all diamonds and
report those diamonds falling within certain sieve-size intervals as these
data are more meaningfully incorporated into a geostatistical database.
Evaluation of diamond distribution size-frequency curves suggests that some
smaller diamonds may be lost during recovery while larger diamonds are not
statistically represented in the parcels. The diamond size considered to be
most representative of the diamond population in any one sample includes
all those diamonds that remain on a 0.3 x 0.3 mm screen and pass through a
1.18 x 1.18 mm screen. For comparative purposes, diamonds that occur in
this size interval for a sample or group of samples are normalized to
diamonds/1000 kg. At this early stage of evaluation, this value is regarded
as the best measure by which to evaluate the variability of diamond
abundance throughout the NW dyke.
Mini-bulk sample results:
Microdiamond results obtained from each of the pits from which
approximately 100 tonnes of kimberlite were processed are presented below.
The samples submitted for microdiamond analyses are approximately
one-quarter of 1 per cent by weight of the mini-bulk samples.
Pit 1 Pit 2
Mini-Bulk Sample Results
Dry Tonnes processed 105.7 94.0
Carats recovered 90.69 138.21
Recovered grade
(carats/tonne) 0.858 1.470
Caustic Fusion Results
Weight processed (kg) 262.62 274.19
Total Diamonds
+0.15mm x 0.15mm screen 503 1001
(normalized to
diamonds/10 kg) 19.2 36.5
Diamonds
+0.30 mm /-1.18 mm 127 241
(normalized to
diamonds/1,000 kg) 484 879
Diamonds
+1.18 mm x 1.18 mm screen 7 2
(normalized to
diamonds/1,000 kg) 26.7 7.3
The three largest diamonds recovered from these caustic fusion analyses of
536.8 kg of kimberlite from both pits are 0.234, 0.208, and 0.130 carats.
These results together with the distribution of coarse diamonds obtained
from processing each of the two 100 tonne samples have been combined to
form a grade-size curve for the samples that will help interpret the
microdiamond analyses of drill intersections from elsewhere on the NW dyke.
Diamond Drill holes:
Microdiamond contents of all significant kimberlite intersections have been
obtained from the spring and summer programs in the Snap Lake area and are
presented below.
NW Dyke
Most diamond drill intersections of the NW dyke were obtained from the
northwest peninsula area of Snap Lake during the summer program. Kimberlite
intersections from 40 holes were analysed from some of which an upper and
lower kimberlite member were analysed separately. Four holes contain only
thin intersections of kimberlite from the thinning up-dip edge of the
kimberlite in the southern part of the peninsula, two holes were drilled
beyond the up-dip edge of the NW dyke, while one hole was not drilled
deeply enough to intersect the NW dyke. All these holes were drilled on
approximately 72 metre centres over the peninsula. In addition, a cluster
of 19 holes on 20 metre centres was drilled in an area proposed for one of
the 1999 bulk sample sites (referred to as the Detailed Area in the table
below). For comparative purposes, the drilled area and the area to be
tested by drilling in the 1999 program have been subdivided into blocks of
400 metre x 400 metre squares. Microdiamond results obtained from within
each of these blocks are presented below:
Microdiamond Analyses
NW Dyke - NW Peninsula area
BLOCK
-----------------------------------------
I-11 J-11* J-12 K-11 K-12 Detailed
Area
-----------------------------------------
Number of intersections
5 19 3 14 4 19
Total weight analysed (kg)
53.76 368.41 82.62 240.75 86.07 369.14
Total diamonds +0.15 x 0.15 mm screen
206 1,504 264 965 322 1,328
(normalized to diamonds/10 kg)
38.3 40.8 31.9 40.1 37.4 36.0
Diamonds +0.3 mm, -1.18 mm
40 362 74 251 88 319
(diamonds/1,000 kg)
744 983 896 1,042 1,022 864
Diamonds + 1.18 mm x 1.18 mm
2 21 1 10 1 9
(normalized to diamonds/1,000 kg)
37.2 57.0 12.1 41.5 11.6 24.3
* Area J-11 data contains only those core intersections from holes drilled
on 72 metre centres. Although the detailed area in which holes were drilled
on 20 metre centres falls with the J-11 block, the two sets of data have
been separated for the purpose of this presentation.
From all the above holes drilled on the NW peninsula during the summer/fall
of 1998, a total of 1200.75 kg of kimberlite was analyzed by caustic
fusion. This is approximately one-half of 1 per cent of the amount of
kimberlite treated from pits 1 and 2. The three largest diamonds recovered
by caustic fusion analyses of this drill core weigh 0.747, 0.691, and 0.469
carats respectively.
North Shore:
Three holes drilled on the north shore in the 1998 summer program
intersected hypabyssal kimberlite dyke material; in one hole, there are two
intersections of dyke material. These holes have opened up the north shore
as an exploration target and appear to have extended the strike length of
the NW kimberlite to approximately 1,350 metres. Although these holes are
located in two separate blocks, they are grouped for the purpose of this
release.
Number of intersections 4
Total weight analysed (kg) 38.72
Total diamonds
+0.15 x 0.15mm screen 194
(normalized to diamonds/10 kg 50.1
Diamonds +0.3mm/-1.18 mm 44
(normalized to diamonds/1,000 kg) 1136
Diamonds + 1.18 x 1.18 mm 0
(normalized to diamonds/1,000 kg) 0
NW dyke - down-dip:
During the 1998 drill programs, three diamond drill holes intersected the
NW dyke down-dip and over a wide area that extends approximately 2,200
metres east of the subcrop on the NW peninsula. Although each hole occurs
in separate 400 metre blocks, they are grouped for the purpose of this
release.
Number of analyses 3
Total weight analysed 33.35
Total diamonds
+ 0.15 x 0.15 mm screen 110
(normalized to diamonds/10 kg) 33.0
Diamonds +0.3 mm, -1.18 mm 27
(normalized to diamonds/1,000 kg) 810
Diamonds +1.18 x 1.18 mm 1
(normalized to diamonds/1,000 kg) 30.0
SE Arm:
During the 1998 spring program, several drill intersections were obtained
of hypabyssal kimberlite and kimberlite breccia material. These
intersections have been interpreted as possibly representing three separate
dykes that dip between 11 and 23 degrees to the northwest; they have been
labeled A, B, and C respectively from southwest to northeast. Caustic
fusion results have been obtained on the more significant intersections
from each of these bodies and are presented below:
DYKE
----------------
A B C
Number of analyses 4 4 8
Total weight
analysed (kg) 18.59 42.36 82.3
Total diamonds
+ 0.15 x 0.15 mm screen 84 176 260
(normalized to
diamonds/10 kg) 45.2 41.5 31.6
Diamonds
+0.3 mm, -1.18 mm 21 49 55
(normalized to
diamonds/1,000 kg) 1130 1157 668
Diamonds
+1.18 x 1.18 mm 0 4 2
(normalized to
diamonds/1,000 kg) 0 94.4 24.3
Grade Estimates:
The microdiamond data from Snap Lake will be used to interpret a diamond
grade above a commercially acceptable bottom stone-size cut-off (for
example, +1.18 mm). With respect to this interpretation, Winspear notes the
following:
Geostatistical evaluation of the data presented above is in progress
and is not yet complete.
There is as yet no firm understanding of the sample size required to
generate a satisfactory grade estimate. For Snap Lake, this refers to
the number of drill holes that may have to be combined to achieve a
usable sample size for grade estimation purposes.
The relation between microdiamond content and those diamonds large
enough to be recovered in a commercial plant is not well understood at
this time. This will be clarified by results obtained from processing
the 6,000 tonne bulk sample later this year. Until then, information
obtained from the mini-bulk sample of 200 tonnes will be used.
By using microdiamond data reported in this fashion together with
macrodiamond recoveries from the mini-bulk samples taken from pits 1 and 2,
a basis has been provided by which grade estimates can be made for other
areas of the dyke. Winspear and its consultants caution against the use of
the caustic fusion data for these purposes. In particular, they note that
such an interpretation assumes a constancy of the grade-size relationship.
It is recommended that microdiamond results not be used for grade
prediction until such time that Winspear and its consultants may announce
the relation between microdiamond content and grade. Until then,
microdiamond analyses are being presented solely as a measure of the
variability of diamond abundance from place to place in the NW dyke.
Winspear notes that while it is attempting to evolve a means of grade
prediction, these techniques cannot be used to predict diamond value.
Summary:
Significant points of the information presented above are as follows:
Evaluation of microdiamond results obtained from the NW peninsula area
suggests that techniques are available by which to compare relative
diamond abundance throughout the NW dyke.
Evaluation of caustic fusion results of drill core obtained from
drilling of the NW dyke in the NW peninsula area during the 1998
summer program indicates that diamond distribution in this area of the
NW dyke is relatively uniform.
Normalized diamond abundance as estimated from caustic fusion results
of drill core is approximately equal to or greater than normalized
diamond abundance estimated from caustic fusion results obtained from
kimberlite representative of pits 1 and 2.
Normalized diamond abundance in pit 1 appears to be significantly
lower than diamond abundance in the NW dyke elsewhere in the NW
peninsula area. By contrast, normalized diamond abundance in pit 2 is
similar to other areas of the NW dyke in the NW peninsula area.
Reasons for this difference between the two mini-bulk sample sites are
being evaluated but may reflect, in part, excess contamination of the
pit 1 sample by footwall rocks during the sampling process.
Despite fewer samples and lower total analysed weights, caustic fusion
results of kimberlite from the down-dip portion of the NW dyke, from
kimberlite on the north shore of Snap Lake, and kimberlite dykes from
the SE arm are consistent with the interpretation that diamond
abundance in these areas is similar to results obtained from drill
intersections of the NW dyke on the NW peninsula.
Winspear remains encouraged by the preliminary results presented above.
These results are the object of continuing work that will be reported when
significant conclusions are available. To facilitate direct comparison of
these results with anticipated results from the 1999 program, Winspear
intends to report new results in a similar format to that above.
(c) Copyright 1999 Canjex Publishing Ltd. canada-stockwatch.com
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