Drilling Update on Droujba Kimberlite
Pipe, Guinea
Stellar Diamonds plc, the
London listed (AIM: STEL) diamond mining and exploration company focused on
West Africa provides an operational update on the drilling programme
at the Company's diamondiferous Droujba kimberlite pipe project located in eastern Guinea.
Highlights:
� Deepest drill intersect recorded to date of 388m
considered highly encouraging
� Drill programme doubled in
scope to 12,000m to test targets defined from orebody
modelling
� Bulk sampling plant being installed on site,
relocated from the Company's Bomboko project
� Further 268kg of drill core sample consigned for
microdiamond analysis in Canada
� Previous microdiamond analysis of 400kg of hypabyssal kimberlite returned
952 diamonds
Chief Executive Karl Smithson commented:
"The drilling programme
at Droujba is progressing well and the significant
intersection of kimberlite at a depth of 388m is
considered to be highly encouraging in terms of the potential tonnage of the Droujba pipe. Based on the interpretation of the drilling
data the Company has elected to double the current 6,000m drilling programme in order to model the ore body to depth and, in
tandem with further microdiamond sampling and a surface bulk sampling programme, establish an initial inferred resource estimate
by the end of the first quarter of 2012. I look forward to updating
shareholders in due course."
Drilling Programme
Drilling at Droujba is on going with a total of 4,400 metres
completed to date from 23 holes. The pipe has been delineated at surface as
being at least 3 hectares in size, with the deepest intersection to date being
at 388m from surface. The orebody comprises two main
intrusions of hypabyssal kimberlite
in an envelope of explosion breccia with varying kimberlite
content. The southern 'blind intrusion' of hypabyssal
kimberlite previously reported has now been
intersected at a depth of between 300m and 400m and remains open at depth,
proving the existence of this kimberlite unit further
to the west and deeper than previously known. Petrographic analysis and
microdiamond results suggest that the southern blind intrusion is very similar
to the hypabyssal unit that reaches surface and was
mined to a depth of 20m in the 1960's by the Russian Aid Mission. Therefore it
is possible that these two separate hypabyssal kimberlite intrusions coalesce at depth, although this
remains to be proven by further drilling.
The expansion of the drilling programme
is designed to further define the kimberlite both
near to surface and at depth, as well as test unresolved geophysical anomalies
and the extensive Katcha kimberlite
dyke which is adjacent to the Droujba pipe. This
additional drilling is included in the current budget.
3D Geological Modelling
Independent 3D modelling has
been undertaken by Datamine in South Africa on the
drilling data received to date. This has defined a geological model containing
4.7 million tons of hypabyssal kimberlite
and 10.4 million tons of kimberlite breccia to a
depth of 350m below surface. This is not yet classified as a mineral resource
estimate. However, it is the objective of the continued drilling programme, microdiamond analysis and planned surface bulk
sampling to define an initial inferred resource in accordance with the JORC (or
equivalent) code.
Microdiamond Sampling and Results
A further sample of 268kg of kimberlite
breccia is currently in the Saskatchewan Research Council laboratory in Canada
for microdiamond analysis. Previous results of a 98kg sample of kimberlite breccia (as reported on the 1st February 2011)
returned 48 diamonds, including one diamond in excess of 5mm in one dimension.
The breccia is volumetrically important to the potential resource and the
Company considers that further microdiamond samples are required to provide a
more representative result. The hypabyssal kimberlite has so far returned abundant diamond counts of
over 2 diamonds per kilogramme. A total of 400.87kg
of hypabyssal kimberlite
has been processed to date and returned 952 diamonds (as reported on the 1st
February and 19th April 2011).
Bulk Sample Processing
A sample processing plant is currently being
established at Droujba. The plant has recently been
relocated from the Company's Bomboko alluvial project
and will be modified to process kimberlite. Once
erected and modified it will be used to process a series of bulk samples of
approximately 2,000 tonnes each from the fourth
quarter of 2011. The bulk samples will test all of the main geological units
identified to date, in order to obtain a representative parcel of diamonds for
valuation. In addition, a bulk sample of the mine dumps that remain from
previous mining undertaken by the Russian Aid Mission in the 1960s will be
tested in order to obtain an early understanding of the potential diamond
quality.
About Stellar Diamonds plc
Stellar is a London (AIM: STEL) listed diamond mining
and exploration company focussed on West Africa.
Stellar owns a 100% interest in four high-grade kimberlite
projects. In Guinea resource definition drilling is continuing on the
diamondiferous Droujba kimberlite
pipe and bulk sampling is underway on the high grade Bouro
kimberlite dyke which is adjacent to the Company's
Mandala alluvial diamond mine. In Sierra Leone at Tongo
a bulk sampling programme is ongoing on the high
grade Dyke 1 and bulk sampling is planned on the Lion 5 dyke at the Kono kimberlite project.