OREAS 72a is a low grade nickel sulphide ore prepared from a blend of high grade nickel ore from the Cosmos nickel mine, Leinster region of Western Australia, and barren alkali olivine basalt from Epping, Victoria, Australia. It is one of a suite of six nickel sulphide CRMs (OREAS 72a to OREAS 77a). The Cosmos nickel mine is operated by Xstrata Nickel and is located in the Kathleen Valley area approximately 30km north of Leinster in Western Australia. It lies within the Agnew-Wiluna portion of the Norseman-Wiluna greenstone belt. This portion of the belt is strongly attenuated and characterised by large scale faults, complex folding and typically steep dips. It is a typical Kambalda-style, komatiite-associated, massive sulphide deposit representing an essentially in-situ accumulation of primary magmatic Ni-Fe sulphides with minor by-products including Cu, Co and platinum group elements (PGE’s). The Cosmos deposit comprises one discrete zone of massive and semi-massive sulphides extending over a strike length of 240m. Mineralisation is strata bound between the overlying ultramafic unit and the underlying dolerite and felsic volcanic rocks. Continuity of grade and width of mineralisation are strong both along strike and down dip.
| CRM Code |
Principle Certified Values |
State |
Matrix |
Mineralization |
| OREAS 72a |
0.693% Ni |
36ppb Pt |
|
41ppb Pd |
mineralised ultramafic |
komatiite-hosted nickel sulphide |