| Thu 12 Feb 2009, 9:00 | | KWR - Kiwara plc - Analytical Work On Kawako Nickel Core Provides Mineralogical |
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KWR
KWR
KWR - Kiwara plc - Analytical Work On Kawako Nickel Core Provides Mineralogical
and Petrographic Evidence to Substantiate the Presence of High Grade Nickel
Mineralisation
Kiwara plc
JSE: KWR
AIM: KIW
ISIN: GB0007702953
("Kiwara" or the "Company")
Analytical work on Kawako Nickel core provides mineralogical and petrographic
evidence to substantiate the presence of high grade nickel mineralisation
The board of Kiwara, the Zambian based exploration Company, is very pleased to
announce the results of follow up analytical, petrographic and mineralogical
work conducted by three independent laboratories Alfred H Knight, Zambia; SGS,
Zambia and Wardell Armstrong, UK on the core obtained from its initial drill
programme at Kawako that intersected wide mineralised packages which included
exceptionally high grades of nickel.
Highlights:
The high grade nickel assays have been verified using various analytical
techniques and confirmed by independent laboratories;
The results confirm that there are no elements which might have an adverse
effect on mining or processing;
Mineralogical work demonstrates the presence of high grade nickel sulphide
minerals;
The nickel-in-soil anomaly associated with the drill intersected nickel
mineralisation has been identified over at least 1.2 km of strike and is open
ended along strike and depth.
Colin Bird (Chairman) says: "We are extremely pleased that the follow-up work
conducted has confirmed the initial result and our original prognosis. Having
confirmed the results, we are currently defining the model prior to implementing
an aggressive exploration programme."
Commentary:
On 23rd September 2008 Kiwara reported the following selected length weighted
average mineralised intersections for which a cut-off grade of 0.2%Ni was
applied:
B/H Depth Depth Intersected Ni
From (m) To (m) width (m) %
KW1 29.50 83.00 53.50 1.07
including 62.80 83.00 20.20 2.16
B/H Depth Depth Intersected Ni
From (m) To (m) width (m) %
KW2 89.22 94.80 5.58 3.20*
104.30 115.17 10.87 6.73*
including 106.15 111.43 5.28 9.78*
including 108.30 109.50 1.20 17.41
and 110.50 111.43 0.93 15.37
Kiwara then undertook to verify these grades by re-assaying selected samples by
varying techniques at different laboratories.
A selection of high grade pulps and coarse reject samples were re-assayed by
Atomic Absorption Spectrometry ("AAS") at Alfred H Knight, Zambia, using both a
partial (aqua regia), total acid (four acid) digestion. All samples were then
analyzed by the Dimethyl Glyoxime method ("DMG"). The results of these
additional tests reported similar values to the originals. These comparative
results would suggest that the bulk of the nickel is readily extractable in
sulphides and silicates or oxides.
A selection of pulps of differing nickel grades were then sent to SGS, Zambia,
for check assay. Separate splits of the samples were analyzed by AAS using both
partial and total acid digestion. The results from both laboratories for Ni
following total acid digestion are very comparable.
Analysis for precious metals and selected trace elements were completed on a
number of samples at Wardell Armstrong, UK. The levels of deleterious elements
such as As (arsenic), Hg (mercury), Cd (cadmium), Te (tellurium) and Se
(selenium) are low. The PGE and Au contents are sub-economic, with maximum non-
coincident values of 25ppb Au, 39ppb Pd and 73ppb Pt. The results for both
boreholes are similar.
The mapping programme recently undertaken at Kawako indicates that the talcose
host rock is preserved on the southern limb of a southwesterly plunging synform
within the southeastern portions of the sampling grid. The most prominent Ni-in-
soil anomaly overlies the talc schist and extends over 1.2km but is open to the
northeast and southwest. The sampling grid is currently being extended to cover
possible extensions.
Selected core samples were then sent for petrographic and mineralogical analysis
at SGS-Lakefield in Johannesburg.
The mineralization in B/H KW1 is dominantly oxide and silicate. The silicate
mineralization is evident lower down in this profile as a distinctive variegated
green mineral which forms coatings and fills vugs, fractures and is also
associated with quartz veinlets. Mineralogical examination indicates that this
green mineral is nepouite or Ni-rich serpentine and the rock has been classified
as a garnierite. The latter consists of the magnesium-rich phyllosilicates
serpentine, talc, chlorite and smectite in which a high percentage of the
magnesium is substituted by nickel to form hydrous Mg-Ni silicate.
The mineralization in B/H KW2 is dominantly sulphuridic. The sulphide
mineralization is present as disseminations, irregular patches, stringers and is
also associated with fractures, veins and is also in crosscutting veinlets of
quartz or quartz-kyanite and therefore, the nickel sulphide mineralization would
appear to have formed by hydrothermal processes. The X-ray Diffraction ("XRD")
and Scanning Electron Microscopy ("SEM") results indicate that the high nickel
grades are associated with the development of high Ni-bearing sulphides, which
are normally associated with supergene enrichment zones. These minerals include
violarite FeNi2S4 (38.93% Ni), millerite NiS (64.67% Ni), polydymite Ni3S4
(57.85%Ni) and vaesite NiS2 (47.78% Ni) - hence the extraordinarily high
intersected Ni grades. Bravoite, pentlandite and pyrrhotite are also present.
Readings taken along the core at 1m intervals from both holes with a
spectrometer indicate that the uranium and thorium levels are low. However, some
of the micas and chlorite contain small amounts of vanadium and Fe-V oxides,
which are often recorded with uranium mineralization and it is intriguing to
note that high grade uranium has been intersected by the Company elsewhere
within the Licence area.
The host rocks predominantly comprise quartz-kyanite-talc rocks which contain
varying amounts of dolomite, hematite, magnesite, phlogopite, chlorite, rutile
and muscovite. These appear to have formed from the metamorphism and alteration
of mixed carbonate, evaporitic and silicate protoliths. The talc-rich hosts are
similar to the "white schists" containing varying amounts of talc, kyanite,
chlorite, quartz, and (rutile and hematite), described elsewhere from the Lower
Roan around the Kabompo Dome which are thought to have formed continental
fluviatile red bed and lagoonal to sabhka environment. The fact that carbonate
pseudomorphs after evaporates are present in some of the rocks, which were
petrographically examined from Kawako by SGS, supports a sabhka-lagoonal
paleoenvironmental setting.
It is conceivable that nickel and vanadium was leached by a hydrothermal fluid
from mafic and ultramafic rocks within the basement during the high grade
metamorphism and deformation. The fluids would then have migrated into a
restricted trap site comprising evaporitic sediments rich in sulphate. It is
also conceivable that the mineralizing fluid originally remobilized some pre-
existing magmatic sulphide deposit which had formed within a buried ultramafic
rock.
There are also anomalous copper-in-soil values within the carbonaceous shale
unit within the hinge zone of the Kawako synform. This anomaly, which extends
over a strike of 1.5 km may prove to be significant given the association of
copper with the carbonaceous shales in the Copperbelt. This is currently being
further investigated by follow-up soil geochemistry.
The Kawako occurrence has a number of significant features:
High tenor nickel minerals are present.
The weathering profile shows considerable supergene enrichment.
Mineralization exhibits a broad stratigraphic control in that the footwall is
lithologically identical in both holes drilled which are some 870m apart.
The mineralized body contains extremely high nickel grades and therefore, vastly
reduced tonnages would be required for a potentially economic deposit and
therefore only a limited strike length of mineralization would need to be
delineated.
The mineralization is potentially open pittable.
About Kiwara:
Kiwara is an exploration company with a focus on base metals in the Republic of
Zambia, which is a major copper producing country.
Kiwara, through its majority owned subsidiary, Kalumbila Minerals, holds
Prospecting Licence 267 which is within the Kabompo Dome in North Western
Zambia, a geologically complex antiformal feature, which contains a number of
base metal and uranium targets. This is within the area considered to be the
western extension of the Copperbelt, an increasingly significant mining area
that contains the recently developed Kansanshi and Lumwana copper mines.
For further information, please contact:
Kiwara Plc Tel: +44 (0)207 581 4477
Colin Bird, Chairman
Peter Vivian-Neal, Chief Executive Officer Tel: +260 (0) 211 293899
Investec Bank, Johannesburg
Robert Smith / Gavin Hall Tel: +27 (0) 11 286 7326
Investec Bank (UK) Limited Tel: +44 (0) 20 7597 5000
Gerard Kisbey-Green
Bishopsgate Communications Ltd Tel: +44 (0)20 7562 3366
Nick Rome
12 February 2009
Sponsor: Investec Bank Limited
Date: 12/02/2009 09:00:05 Produced by the JSE SENS Department.
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