todays annoucement

DiamonEx
Limited
ABN 26 091 951 978
Sky Level
301 Coronation Drive
Milton Qld 4064
Australia
Telephone: +61 7 3369-6399
Facsimile: +61 7 3369-6077
e-mail:
[email protected]
Postal Address:
PO Box 1357
Milton Qld 4064
ASX ANNOUCEMENTS
AUSTRALIAN STOCK EXCHANGE 3 February 2005
INDICATOR MINERAL CHEMISTRY ANALYSES
MARTIN’S DRIFT DIAMOND PROJECT
The directors of DiamonEx Limited are pleased to present the first indicator mineral
chemistry analyses of grains recovered from the +1mm fraction of 361 samples taken over an
approximately 35 Hectare photographic anomaly in the Martin’s Drift Diamond Project,
North-East Botswana.
SUMMARY RESULTS:
• 40 pyrope garnets recovered, 14 of which classified at G10 garnets
• 63 ilmenites recovered. Composition of approximately 50% of these indicate that if
diamonds are present in the source body, they are likely to be preserved
• 11 spinels recovered. Analysis of available spinels provide high-interest trends,
indicating a probable diamondiferous source
Mineral chemistry analysis of the 40 pyrope garnets recovered form this size fraction indicate
that 14 plot within the G10 field as described on the standard interpretive graph based on the
work of Gurney (1984).
Assessment of analyses included a comparison of the visible similarities and differences in the
trends exhibited by the 40 pyrope grains recovered from samples over the anomaly, with the
available mineral chemistry trends of pyrope garnets from the nearby kimberlites K003, K004
and K006. No garnet data is available from kimberlite K005. A summary of this comparison
is attached as Table 1.
Given that the analyses available to DiamonEx at this juncture derive solely from grains
recovered from the +1mm size fraction, better interpretations of the trends will be possible
when the analyses of grains from the -1+0.5mm fraction become available. However, there
are sufficient differences evident in the current analyses to suggest that an unknown source or
sources is/are at least partly contributory to the population of grains recovered over the
photographic anomaly.
The analyses of the spinel and ilmenite populations complement the results of the pyrope
analyses, indicating that co-existing diamonds should have been present in the source rock at
the time of intrusion and would have been preserved at the time of emplacement.
Approximately 50% of the ilmenites recovered contain 8% or greater weight percentage
magnesium oxide (MgO), indicating that if diamonds are present in the source body, they are
likely to be preserved. Only 11 spinel analyses are available from this size fraction, but highinterest
trends, indicating a probable diamondiferous source, may be discerned in the graphs
based on the work of Fipke et.al. (1995).
Three diamonds were also recovered from this size fraction, as reported in an earlier
announcement.
These observations, coupled to the very strong indications of a nearby source, derived from
the previously reported surface texture work on these grains, serve to heighten the interest of
this anomaly.
Table 1
Trend Similarities Trend Differences
K003
Pyrope Garnets
(580 grains)
The percentages of grain
analyses on either side the
lherzolite line.
A clustering of analyses around 4
wt% Ca0, 8 wt% Cr2O3 – an
embryonic cluster is seen in the
grains from the anomaly at 5.2 wt%
CaO, 8.8 wt% Cr2O3;
No grains with <4 wt% Cr2O3;
Grains with an eclogitic paragenesis
(0 wt% Cr2O3)
K004
Pyrope Garnets
(347 grains)
The percentages of grain
analyses on either side the
lherzolite line
No grains with <2 wt%; No grains
with <4 wt% Cr2O3;
Grains with <2 wt% CaO;
No grains clustering in the G10 field.
K006
Pyrope Garnets
(74 grains)
Some clustering of G9 grains
at 6.5 wt% CaO, 8-9 wt%;
Grains with <4 wt% Cr2O3.
Dissimilar distributions of grain
analyses on either side of the
lherzolite line.
Paul Crawford
Company Secretary
For further information, please contact:
Dan O’Neill (Managing Director) Greg King (Chairman)
+61 7 33696399 (Office) +61 7 33696399 (Office)
+61 7 33696077 (Fax) +61 7 33696077 (Fax)
+61 407596942 (Mobile) +61 411473730 (Mobile)
[email protected] (Email) [email protected] (Email)