Perseverance Mine, Leinster, Leonora Shire, Western Australia, Australiai

Regional Level Types
Perseverance Mine	Pit (Inactive)
Leinster	- not defined -
Leonora Shire	Shire
Western Australia	State
Australia	Country

Komatiite-related copper-nickel sulfide deposit. One of the largest nickel deposits in the world, with reserves of 45 million tons of ore grading at 2.05% nickel.

Located a few kilometres north of Leinster, the town established in 1976 by Agnew Gold Mining for its nickel operations. The mine was later taken over by Western Mining Company, then BHP Billiton which operated it under the name Nickelwest. The mine is named after a nearby well. It is also sometimes referred to as the Leinster or Agnew Mine.

It was an open pit with an underground mine to 1400 metres below the surface and was one of the deepest in Australia. The mine came under scrutiny for a poor safety record (by Australian standards), much of this caused by significant seismic events.

The mine was closed by BHP in late 2013.

The mine is situated in the greenstone belt of felsic volcaniclastic sediments and lavas, with intermittent komatiite and black sulphidic graphitic shales. All the mineralisation is in the komatiite. This occupies an overturned eastern limb of a regional anticline. The Komatiite banding is thick layers of olivine ortho-mesa cumulate, capped by a succession of thin spinifex textured flows. The core of the komatiite is called the Perseverence ultramafic complex, which is a thick intact accumulation of olivine-rich ultramafic rocks in which the primary igneous cumulate textures are preserved.

The ore-body is at the base of this complex and is composed of high grade and heavily disseminated sulphides, with an extension sheet of weak sulphide mineralisation. The massive sulphide displays strong tectonite fabrics and is located in a structurally complex position, within the weakly mineralised zone. It occurs as a series of steep dipping, north striking, individual, fault-bounded sheets resulting from physical remobilisation of the fault-related lodes and fold hinges. The main mineralisation is a series of vertically stacked lenses. The surrounding weak sulphide envelope shows disseminated sulphide forming a distinct shoot, plunging 70 degrees south at more than 1100 metres below the surface, and striking north, dipping steeply to the west.

The heavy disseminated ores in the central zone contain Ni of over 1.5% and 20% of the volume of the ore with pyrrhotite and pentlandite dominant. The marginal zone flanking this central zone also has these species as dominant. The weakly disseminated sulphide sheet has Ni at 0.5 to 0.7% and 5% of volume as lobate aggregates of pyrrhotite and pentlandite.

World-class millerite specimens and takovite/eardleyite have come from the mine and a few other species of average importance. Okenite has also been found which is rare in Australia.

Other Regions, Features and Areas containing this locality

References