Perseverance Ni Mine (Agnew; Leinster), Leinster, Leonora Shire, Western Australia, Australia
|Latitude & Longitude (WGS84):||27° 48' 55'' South , 120° 42' 15'' East|
|Latitude & Longitude (decimal):||-27.81528,120.70417|
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 operates it under the name Nickelwest. The mine is named after a nearby well. It is also refered to as the Leinster or Agnew Mine. (However it is preferred that it isn't, due to confusion with the Agnew Goldfield to the west, or the Leinster town site).
It is an underground mine to 1400 metres below the surface and is one of the deepest in Australia. The mine has come under scrutiny in recent years for a poor safety record (by Australian standards).
The mine is situated in greenstone belt of felsic volcaniclastic sediments and lavas, with intermittant 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 that are the result of 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 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. We should be thankful any specimens are seen considering the industrial scale of the mining operation.
28 valid minerals.
Rock Types Recorded
Select Rock List TypeAlphabetical List Tree Diagram
Entries shown in red are rocks recorded for this region.
This geological map and associated information on rock units at or nearby to the coordinates given for this locality is based on relatively small scale geological maps provided by various national Geological Surveys. This does not necessarily represent the complete geology at this locality but it gives a background for the region in which it is found.
Click on geological units on the map for more information. Click here to view full-screen map on Macrostrat.org
2500 - 4000 Ma
|sedimentary rocks 74322|
Age: Archean (2500 - 4000 Ma)
Description: Phyllitic schist, siltstone, sandstone, greywacke, pelite, conglomerate, quartzite, phyllite, shale, slate, claystone, chert, minor felsic volcanic and volcaniclastic rocks; arkose, para- and orthoamphibolites; rare banded iron formation
Comments: argillaceous detrital sediment; sedimentary siliciclastic; synthesis of multiple published descriptions
Lithology: Argillaceous detrital sediment; sedimentary siliciclastic
Reference: Raymond, O.L., Liu, S., Gallagher, R., Zhang, W., Highet, L.M. Surface Geology of Australia 1:1 million scale dataset 2012 edition. Commonwealth of Australia (Geoscience Australia). 
Marston, R.J. (1984): Nickel Mineralisation in Western Australia. Geological Survey of Western Australia (1984)
Economic Geology (1988) 83:524-536.
Economic Geology (1988) 83:537-550.
Naldrett, A.J. (2004): Magmatic Sulfide Deposits. Springer (Berlin, Heidelberg (New York)(2004): 740.
Grguric, B.A., and Nickel, E.H. (2005): Okenite from the Perseverance Nickel Mine, Western Australia- a first Australian occurrence. Australian Journal of Mineralogy (2005):11: 25-26.
Mineralium Deposita 45 (2010): 281-311.