TSD News release
Tsodilo Resources Limited: Further Interpretation Of Drilling
Results
via COMTEX
February 24, 2004
TORONTO, Feb 24, 2004 (BUSINESS WIRE) --
Tsodilo Resources Limited (TSX Venture Exchange: TSD) are
pleased to announce an update on the Company's Ngamiland
diamond exploration program, including a further interpretation
of their geophysical survey and reverse circulation drilling results
on the A37 and A12 kimberlites.
Exploration Program Summary
Tsodilo's exploration program consists of a number of individual
projects. The most important of these are:
1. Evaluation of the recently discovered A37 and A12 kimberlites
in the Nxau Nxau kimberlite field, and the investigation of further
magnetic targets which, it is believed, could reflect a significant
extension of this field to the south.
2. Follow-up of further magnetic targets in the Guma area in the
east of the licence block to locate the source of unexplained
Kimberlitic Indicator Minerals (KIMs) recovered by our soil
sampling programs in this area.
3. Follow-up of magnetic targets associated with unexplained
KIMs in the south of the ground held by the company's
Botswana-registered 75% held subsidiary, Newdico.
4. Investigation of bulls-eye magnetic anomalies in the
Prospecting Licences recently acquired by the company's wholly
owned subsidiary, Gcwihaba Resources. This ground is located
to the south of the Newdico Licences.
Evaluation of the A37 and A12 Kimberlites
The evaluation of the recently discovered A37 and A12
kimberlites in the Nxau Nxau cluster represents of the most
advanced of the company's projects.
Additional chemical analyses for Niobium and Nickel in drill
samples confirms our previous cautiously expressed view that
the drilling had indeed intersected kimberlite crater facies
sediments. Essentially, kimberlites tend to be relatively enriched
in Niobium (Nb) and Nickel (Ni) relative to most other rock types.
When a kimberlite erupts, particularly if it encounters
groundwater and explosively fractures the country rock, a mixture
of kimberlite material and country rock fragments are blown into
the air to form an unstable cone around the kimberlite. This
mixture of kimberlite and country rocks then collapse back into
the crater to form the crater sediment sequence. The lowermost
crater sediments are formed by unstable debris flows
('landslides') giving rise to coarse, poorly-sorted basal deposits
while the waning phases of sedimentation in the crater are finer
clays settling out of the crater lake giving rise to a series of
shales and mudstones. Chemically, the crater sediments will
reflect this mixture of reconstituted country rocks and kimberlite
tuffs. Our drilling and chemical results indicate deep weathering
of these sediments, which has led to strong leaching of the
elements that are typically concentrated in kimberlitic crater
sediments.
The gravity and magnetic data from ground surveys over the A37
kimberlite are interpreted to indicate that there is a major
kimberlitic crater and at least two closely associated subordinate
craters with a number of kimberlite intrusive centres. It is
therefore similar to many of the world's large kimberlites in being
a composite body. We estimate that the main A37
sediment-filled crater is some 1000m in length by 500 to 600m
in width and that the total surface area, including the subsidiary
basins to the east and north, is 80 -120 hectares. While further
drilling will be needed to delineate the body with greater
accuracy, it seems as though this will be the second or third
biggest kimberlite found in the Republic of Botswana, the largest
producer of diamonds, by value, in the world.
The drilling results therefore confirm our earlier geophysical
interpretation of this composite kimberlite intrusion. The
dolomitic limestone country rock probably contained
considerable amounts of groundwater in solution cavities at the
time of the kimberlite eruption. The very hot kimberlite,
encountering this water, turned it to steam and resulted in a very
large explosion that caused extensive fracturing of the dolomite
in what is termed a 'phreatic eruption'. The large surface area of
the resulting crater sediments and its flat,
'champagne-glass'cross-sectional shape bear testimony to this
event.
It should be noted here that there are several examples
world-wide of very high-grade producing diamond mines where
similar 'phreatic eruptions'of kimberlite occurred. The Mbuji Mayi
mine in the Kasai Province of the Democratic Republic of the
Congo consists of an elongate group of 10 kimberlite pipes
along a linear zone some 3,500 metres long by 800 metres wide
and also erupted through dolomitic limestone country rock
leaving a flat 'champagne-glass' cross-sectional shape and
extensive crater sediments. Other examples of the development
of diamondiferous crater sediments are at the Argyle mine in
Australia, the Lac de Gras kimberlite cluster and the Orapa mine
some 500 Km. southeast of A37. The high grades associated
with these kimberlites may indicate that the phreatic eruptive
processes favour the preservation rather than the resorption of
the diamonds.
Our drilling results indicate that the A12 kimberlite intruded
through quartzite country rock, probably containing less ground
water with a less explosive eruption and therefore differs from
the A37 body in having a 'carrot'shape, making it more similar to
pipes elsewhere in southern Africa, and those in the Lac de
Gras field in Canada.
Composite samples of drill chips from A12 and A37 have been
collected and bagged for shipment to Canada where
micro-diamond analyses will be done. The results are only
expected by July 2004 when additional drilling of the two
kimberlite occurrences will be planned on a systematic grid to
better define the size and shape of the craters, their kimberlite
pipe feeders and to collect sufficient samples for a reasonable
estimate of the grade and value of any diamonds in the
kimberlites.
Soil Sampling Program
Canadian geophysical contractors using a variety of different
algorithms recently reprocessed our aeromagnetic data. This
enhanced dataset was screened and over 100 bulls-eye
magnetic targets selected for a follow-up sampling program.
The targets are located in several areas where previous
sampling has outlined isolated unexplained KIM anomalies.
This suggests that they could represent at least three virgin
kimberlite fields, as well as an extension of the known Nxau
Nxau field to the south. Detailed KIM soil sampling over these
anomalies will begin in March after the worst of the rainy season
is over. Detailed gravity surveys and first-phase drilling of the
positive targets will follow this program.
Tsodilo Resources is an international diamond exploration
company engaged in the search for economic kimberlites at its
Newdico and Gcwihaba projects in northwest Botswana. Tsodilo
has a 75% stake in Newdico while Trans Hex Group, a South
African diamond mining and marketing company, holds the
remaining 25%. The recently granted southern 'Gcwihaba
Project'area is held by subsidiary Gcwihaba Resources and
agreement in principal has been reached with SouthernEra
Resources for their participation as to 50%. The exploration of
both licence areas is managed by Tsodilo. The design and
conduct of the Company's exploration program is the
responsibility of Dr. Andrew Moore, a professional geologist
registered with the South African Council for Natural Scientific
Professions.
The TSX Venture Exchange does not accept responsibility for the
adequacy or accuracy of this release.
SOURCE: Tsodilo Resources Limited
Tsodilo Resources Limited
James M. Bruchs
jbruchs@tsodiloresources.com
or
Dr. Andrew E. Moore
amoore@tsodiloresources.com
or
Head Office:
Telephone: 416-572-2033
Fax: 416-572-4164
info@tsodiloresources.com
https://www.tsodiloresources.com