|Latitude & Longitude (WGS84):||30° 30' 35'' South , 121° 13' 31'' East|
|Latitude & Longitude (decimal):||-30.50984,121.22554|
|Köppen climate type:||BSh : Hot semi-arid (steppe) climate|
Golden Kilometre is a mine in the Mount Pleasant complex, with the Lady Bountiful mine to the north, and to the south a tailings pond storage area and machinery sheds. There are several pits in the immediate area of Golden Kilometre, including one filled in with tailings. The mine produced 2.5 Mt at 4.2 g/t.
The deposit is hosted by the quartz-gabbro Mount Pleasant Sill, basalt, and a shale horizon between the two. Economic mineralisation is largely confined to the quartz-gabbro sill, with minor amounts in adjacent units.
The sill is the most fractured, and Fe rich rock in the Greenstone succession. The greater brittle quartz content has mean't it is more amenable to fracturing, thus allowing gold carrying fluids more access to the rock. Gold mineralisation is controlled by brittle-ductile strike slip faults, associated systems of laminated quartz veins, related altered wall rock, and minor brecciation zones. The major quartz veins are up to 1 metre wide, laminated, with narrow ribbons of pyritized wall rock.
There are three distinct ore shoots called Golden Kilometre, North and North-South. Mineralisation for Golden Kilometre occurs along a main D fault 2 to 6 metres thick. It splays and anastromoses along its length. South and North-South mineralisation is controlled by an oblique fault. South is a major quartz shoot, and has numerous splays of variable orientations, with a wide alteration halo. The highest gold grades is where veins intersect. North-South is a narrow 1 to 2 metre massive to poorly laminated quartz veins and brecciated zones.
Alteration in wall rock shows actinolite-chlorite, replaced by chlorite-albite-biotite-calcite. within a chlorite-calcite distal zone. Intense alteration near the veins is to muscovite-ankerite-pyrite-pyrrhotite-chalcopyrite-sphalerite-arsenopyrite. The muscovite-ankerite zone can be sub-divided into a distal pyrrhotite and proximal pyrite sub-zones.
In the wall rock, gold occurs as discrete particles in gangue and sulphide minerals. Gold occurs in the quartz veins as coarse grains 1-2 mms, with recrystallised quartz, or with sericite, chlorite and ankerite. Gold bearing veins also contain minor galena, sphalerite, pyrrhotite, chalcopyrite and scheelite.
Commodity ListThis is a list of exploitable or exploited mineral commodities recorded at this locality.
17 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
0 - 2.588 Ma
Age: Pleistocene (0 - 2.588 Ma)
Comments: regolith; synthesis of multiple published descriptions
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.