|Latitude & Longitude (WGS84):||28° 2' 41'' South , 117° 49' 15'' East|
|Latitude & Longitude (decimal):||-28.04478,117.82076|
|Köppen climate type:||BWh : Hot deserts climate|
The mine is considered the largest producer in the area. Since 1891 it has produced over 5.6 million oz of gold.
Robert Austin explored the area in 1854, and noted the iron in the hills played havoc with his compass, hence the name. He also reported the area probably contained significant gold, but his report drew little attention. Gold was discovered in July 1891, with very rich alluvial finds at the mis-named Poverty Flats. The largest nugget found was 100 oz. Thirty gold mines were developed in the immediate area around the town of Mt Magnet.
Mining appears to have occurred at the site from shortly after 1891, but was only known as Hill 50 from 1934 when the Hill 50 Gold Mine Limited was formed. Mining started under this name in 1936. Unlike many of the mines in the district it continued operations through World War Two. It was Australia's most profitable mine between 1955-1961. A new shaft was sunk to 300 metres, and a new steel headframe constructed in 1956. At this time most gold was being found between 180-400 metres below the surface.
From 1961 profits gradually decreased in line with decreasing gold grades, and the increasing depth of ore (eventually 1500 metres making it Australia's deepest mine). The mine closed in 1976. Hill 50 re-opened in 1981 with several open pits developed, including Mars and Saturn.
Western Mining took over the company and mine in 1987, and re-opened the nearby Morning Star mine. Wattle Gully Gold Mines (later Hill 50 Gold) acquired the Hill 50 mine in 1997, and re-opened the Hill 50 site with some success. Harmony acquired Hill 50 Gold in 2002. The mine closed again in 2007, citing a lack of gold reserves. Monarch Gold attempted to purchase the mine later in 2007, but defaulted on its final payment, and the company went into administration. In 2010 the mine was sold to Ramelius Resources, who commenced open pit operations in 2011. There are several pits in close proximity to each other including Brown Hill, Mars, Titan, Jupiter, Saturn and Perseverance.
The Hill 50 Gold Mine is in the Meekatharra-Mt Magnet Greenstone Belt, of mafic, ultramafic, and felsic volcanics, interbedded with banded iron formations. The greenstone belt has been complexly deformed into a domal structure with a steep plunging synform called the Boogardie Syncline. It is faulted against the younger sediments to the east, and invaded/flanked by granitic structures, batholiths and gneissic granitoids. North north-east striking faults, known as the Boogardie Breaks, are superimposed on the synform, and form important structural controls as to where gold is found.
Gold is hosted in banded iron formations of the Sirdar Formation, up to 20 metres wide, showing alternating 1-10mm thick laminae of microcrystalline quartz, iron oxides, and carbonates. Gold is closely associated with pyrrhotite and to a lesser extent pyrite.
Gold in also found in quartz veins either in intensely deformed pre metamorphism basalt hosted vein systems, or late stage ultramafic and mafic hosted veins in shears.
Commodity ListThis is a list of exploitable or exploited mineral commodities recorded at this locality.
11 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
|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. 
2500 - 4000 Ma
|tuffaceous sandstone 74304|
Age: Archean (2500 - 4000 Ma)
Comments: sedimentary siliciclastic; synthesis of multiple published descriptions
Lithology: 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).