|Latitude & Longitude (WGS84):||31° 21' 25'' South , 121° 30' 5'' East|
|Latitude & Longitude (decimal):||-31.35720,121.50149|
|Köppen climate type:||BSk : Cold semi-arid (steppe) climate|
Discovered by Selcast Exploration Ltd in the late 1960s. This was a nickel mine (with minor copper). The mine is located about 2 kilometres west of the Coolgardie-Norseman Highway at the Emu Rocks location. Access is via the Wattle Dam access road.
Pre mine resources was 660 000 tonnes at 2.47% Ni. The establishment of the underground mine in the mid 1970's, led to Selcast ceasing exploration in the area. The company had previously also discovered the 1A, 5A, and 5B deposits. Production from Andrew's Shaft occurred between 1974 to 1979 developed by Selcast and BP Minerals Australia.
It is a massive sulphide deposit associated with the basal contact of komatiite flow units, and has a high arsenic content.
Located on the western limb of an anticlinal structure. The ultramafic host is 100 to 150 metres thick of layered olivine peridotite, with upper tremolite, chlorite, serpentine. The Footwall is hornblende and calcic-plagioclase, with flattened pillow structures common.
Chloritic or biotitic metasomatic reaction zone on contacts between quartz-feldspar-albite porphyry intrusions, and the ultramafic rocks. Also fine grained metasedimentary rocks containing quartz, albite, pale amphibolite, chlorite, graphite, carbonate, with varying amounts of pyrrhotite, minor chalcopyrite and sphalerite.
The ultramafic rocks dip 70 degrees west, and are locally overturned, extending a length of 300 metres. The deposit contains three shoots, and a small body of Hanging Wall mineralisation. Shoot number 3 is most persistent, but extends less than 50 metres.
Most mineralisation is disseminated to matrix sulphides, increasing tending to massive at depth. Shoot 2 contains more massive sulphide, associated with porphyry intrusions.
Primary mineralisation is pyrrhotite, pentlandite, minor pyrite, smythite, chalcopyrite, magnetite, chromite. The oxidised zone extends down 70 metres from the surface, and then a transition zone to 120 metres. The deposit grades at 7-12% Ni.
11 valid minerals.
Rock Types Recorded
Select Rock List TypeAlphabetical List Tree Diagram
Entries shown in red are rocks recorded for this region.
- Igneous rock
- Sedimentary rock and sediment
- Metamorphic rock
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
|undivided sedimentary and volcanic rocks 74481|
Age: Archean (2500 - 4000 Ma)
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). 
|Neoarchean - Mesoarchean|
2500 - 3200 Ma
|Archean volcanic rocks|
Age: Archean (2500 - 3200 Ma)
Comments: Yilgarn Craton
Reference: Chorlton, L.B. Generalized geology of the world: bedrock domains and major faults in GIS format: a small-scale world geology map with an extended geological attribute database. doi: 10.4095/223767. Geological Survey of Canada, Open File 5529.