Western Australia, WA, Australia
Ni Cu Co
New & Recent International |
Click on image for details.
The Nova-Bollinger magmatic nickel-copper deposits are located in the Fraser Range Orogen of Western Australia, ~120 km east of Norseman and 220 km SW of Kalgoorlie (#Location: 31° 49' 7"S, 123° 11' 50"E).
The Nova deposit was discovered by drilling coincident geochemical and electromagnetic anomalies on the north-western side of an eye-like structural feature observed in regional and ground magnetic data. The Nova discovery hole was drilled in July 2012, and a maiden resource released in May 2013. In the meantime, in February 2013, the nearby Bollinger Deposit was discovered.
The Nova and Bollinger deposits are hosted within the lower granulite facies mafic metamorphosed rocks of the Fraser Range Domain of the Albany-Fraser Orogen. This domain is dominated by metamorphosed mafic rocks, but also includes similarly metamorphosed granitic and sedimentary rocks. Much of the northern section of the domain is masked by younger rocks of the Eucla Basin, although on the basis of geophysical data, it is interpreted to constitute a continuous, NE-trending belt that is ~425 km long by ~50 km wide.
Host rocks to the deposits comprise a suite of meta-gabbroic to meta-picrite cumulate protoliths which have been metamorphosed to lower granulite facies. These units are interpreted to have been emplaced as layered sills in an extensional sedimentary basin. Primary igneous textures are locally preserved within the mineralisation and the enclosing mafic protolith, although most of the rocks have been strongly deformed and recrystallised to gneisses.
The mineralisation occurs as three stacked lenses, Nova, Bollinger and Tethys, composed of massive-, matrix-, disseminated- and breccia-textured sulphides. These are interpreted to represent magmatic sulphide accumulations at the base of stacked mafic sills that intruded the sequence of basinal sedimentary rocks. Each lens is connected by thinner sheets of magmatic sulphide breccia which are interpreted to represent inter-chamber feeder zones. The mineralisation has been tectonically deformed, and now comprises tectonic sulphide breccias and silicate-sulphide laminated rocks formed by preferential remobilisation of sulphides during peak deformation.
The sulphide assemblage comprises coarse grained, discrete exsolved crystals of pyrrhotite, pentlandite and chalcopyrite, and the enclosing silicate gangue minerals include orthopyroxenes, clinopyroxenes, olivine, quartz and garnet. The sulphides comprise ~80 to 85% pyrrhotite, ~10 to 15% pentlandite and 5 to 10% chalcopyrite.
Mineral Resources and Ore Reserves as at 30 June, 2016 were as follows (Independence Group NL Annual Mineral Resource and Ore Reserve Statement, 14 October, 2016):
Mineral Resources at a 0.6% Ni equivalent cut-off
Indicated Resource - 9.1 Mt @ 2.5% Ni, 1.0% Cu, 0.08% Co,
Inferred Resource - 1.0 Mt @ 1.4% Ni, 0.6% Cu, 0.05% Co,
Sub-total - 10.1 Mt @ 2.4% Ni, 1.0% Cu, 0.08% Co.
Indicated Resource - 2.4 Mt @ 2.7% Ni, 1.1% Cu, 0.11% Co,
Inferred Resource - 1.8 Mt @ 1.0% Ni, 0.4% Cu, 0.04% Co,
Sub-total - 4.2 Mt @ 2.0% Ni, 0.8% Cu, 0.08% Co.
TOTAL Mineral Resource - 14.3 Mt @ 2.3% Ni, 0.9% Cu, 0.08% Co.
Ore Reserves, which are included in Mineral Resources
Probable Reserve - 10.9 Mt @ 2.0% Ni, 0.8% Cu, 0.06% Co,
Probable Reserve - 2.7 Mt @ 2.2% Ni, 0.9% Cu, 0.09% Co,
TOTAL Ore Reserve - 13.6 Mt @ 2.0% Ni, 0.8% Cu, 0.07% Co.
The most recent source geological information used to prepare this summary was dated: 2016.
This description is a summary from published sources, the chief of which are listed below.
© Copyright Porter GeoConsultancy Pty Ltd. Unauthorised copying, reproduction, storage or dissemination prohibited.
Top | Search Again | PGC Home | Terms & Conditions