Nickel Overview
Duketon Greenstone Belt Projects West Australian Map
South Boulder’s Duketon Greenstone Belt is considered highly prospective for nickel, copper and platinum group elements.
In 2004 South Boulder signed a farm-out Joint Venture agreement with Independence Group NL (IGO). The agreement allows IGO to earn 70% of the nickel rights on South Boulder tenements within the Duketon Greenstone Belt by completing a Bankable Feasibility Study within five years.
Two key prospects have been defined to date: Rosie and C2. Other than these prospects much of the highly prospective ultramafic units have yet to be effectively tested for nickel-copper-PGE sulphide mineralisation at depth.
The C2 Deposit was discovered by aircore drilling, conducted by IGO in 2008. Another round of aircore drilling in early 2010 led to the discovery of the Rosie Deposit. The prospects are approximately 2km apart and the mineralisation at both is considered open in most directions.
The mineralisation at the Rosie Deposit is currently defined over an approximate strike length of 950m and a dip extent of 600m. Results have confirmed a laterally extensive zone of predominantly disseminated and breccia style mineralisation with discrete zones of massive sulphide mineralisation. This style of mineralisation is suggestive of remobilised sulphides possibly flanking a massive sulphide mineralised “channel” or footwall embayment position. Intercepts include up to 3.3m (true width) @ 9.7% Ni, 1.1% Cu, 0.2% Co and 7.1g/t PGEs (2.2g/t Pt, 1.7g/t Pd, 0.8g/t Rh, 1.8g/t Ru).
The massive sulphide mineralisation at the Rosie Deposit has an ultramafic hanging wall and sediment-free basaltic footwall, and is interpreted to represent a classic Komatiitic lava channel. However, the high copper, cobalt and platinoid assays are atypical of known lava channel nickel sulphides in Western Australia. The MLTEM coverage indicates a strong continuous conductor through this area.
Mineralisation at the C2 Deposit is semi-continuous over at least 700m of strike, and is known to extend to at least 300m below surface, up to 25m wide (true width). The mineralisation appears to be east dipping, in two to three contact-parallel layers, an upper, central and lower zone. These zones can, in places, be traced from one section to another, based on their spatial distribution and elemental signatures.
High Grade Nickel Sulphides from Rosie Deposits
The mineralisation comprises of disseminated and minor matrix and stringer sulphides and is considered to have potential to host massive sulphide mineralisation. The best intercept at the C2 Deposit is comprised of disseminated, stringer and breccia sulphides, with intercepts of up to 52m @ 0.9% Ni, including 37m @ 1.05% Ni, with zones of higher mineralisation grading up to 3.34% Ni. There is potential at C2 for further discrete, higher grade, massive sulphide zones similar to those found at Rosie.
A 102 hole aircore program for 6,500m was completed along the ultramafic contact northwest along strike from the Rosie Deposit and along the Bulge western contact. A number of anomalous results were returned.
Initial resource diamond and RC drilling has now been completed at the Duketon Nickel JV. Strong mineralisation continued to be intersected confirming the potential for a mine development. Exploration is to intesify.