Copper Hills Mine, Nullagine, East Pilbara Shire, Western Australia, Australiai

Regional Level Types
Copper Hills Mine	Mine
Nullagine	- not defined -
East Pilbara Shire	Shire
Western Australia	State
Australia	Country

Porphyry copper deposit.

Dec 2012- is different locality to Copper Hills found in Rudall River District.

Discovered 1952. To 1963, produced 49.22 tonnes of copper ore, and 15 455.67 tonnes of cupreous ore, averaging 12.68% Cu. Between 1969-1972, S.H. Stubbs produced a small amount of 'cement' copper from the leaching plant that had remained at the site. Mine workings cover an area 150 metres long by 50 metres wide, in a saddle in an isolated north north-east trending ridge. The main underground shaft was at the southern end of this.

Hosted at the north end of a quartz-feldspar-biotite pegmatite, with a dark green groundmass called the Boobina Porphyry. Locally however the porphyry is pale grey-green, containing corroded quartz and/or albite or orthoclase phenocrysts, in a matrix of quartz, sericite, feldspar, minor chlorite, carbonate, pyrite and chalcopyrite. Zones of darker chloritic porphyry are noted, with the outcrops deeply weathered, fractured and sheared. The porphyry is surrounded by fractures covered in green malachite staining.

In addition, minor pyrite is disseminated through the porphyritic host, with chalcopyrite and magnetite, with trace sphalerite and pyrrhotite. The mineralisation is in quartz veins along shears cutting feldspar porphyry.

Supergene oxides, and sulphides including malachite, azurite, chalcocite, and bornite. Primary pyrite and chalcopyrite is disseminated in porphyries, and on fractures. There is an absence of quartz vein stockworks. Epidote alteration is noted, with pervasive kaolinite and sericite, overprinting in the outcrop to the oxidation of the sulphides during weathering.

Other Regions, Features and Areas containing this locality

References