Aphrodite gold prospect, Bardoc, Broad Arrow Goldfield, Kalgoorlie-Boulder Shire, Western Australia, Australiai

Regional Level Types
Aphrodite gold prospect	Prospect
Bardoc	- not defined -
Broad Arrow Goldfield	Ore Field
Kalgoorlie-Boulder Shire	Shire
Western Australia	State
Australia	Country

The Aphrodite gold prospect is part of the Bardoc Shear Zone, which roughly follows the Goldfields Highway 120 kilometres from Kalgoorlie to Menzies.

The anomaly was discovered in 1993 to 1994, which uncovered a supergene zone immediately above the weathering front at a depth of 50 metres. Drilling from 1996 proved an oxide resource with underlying primary mineralisation named Alpha and Phi, discovered from drilling across 1998 to 1999. The exploration was conducted by Goldfields Ltd.

The upper levels contain 5 to 10 metres of gravelly to sandy soil; 1 to 10 metres of carbonate enriched soil with dark red to brown lateritic fragments; plastic smectite clay; then 20 to 50 metres of kaolin dominated saprolite clays over lower saprolite to a depth of 70 metres.

The Alpha and Phi zones are hosted in a dilational complex of intermediate porphyries, and predominantly volcaniclastic rocks, on the boundary of the Ora Banda and Boorara Domains. Gold is found in sericite-pyrite-arsenopyrite alteration system 3 kilometres striking north-south. Most gold is found in high strain zones sub parallel to the stratigraphy in a series of north north-west to north sub vertical brittle-ductile fault zones.

Primary mineralisation in Alpha is found in a vertical to steep east dipping planar body, striking a length of 440 metres, and 5 metres wide, cutting across host felsic porphyry and sediments. Phi is predominantly hosted by volcaniclastic rocks between two porphyry bodies, one of which hosts Alpha. Primary mineralisation at Phi strikes a length of 440 metres to a depth of 400 metres, vertical to steep west dipping and 10 to 50 metres wide. Alpha is high grade and narrower than Phi.

Gold is associated with zones of quartz-pyrite-arsenopyrite veins or breccias, and texturally destructive sericite-pyrite-arsenopyrite-galena-chalcopyrite-stibnite-fuchsite alteration.

A pyrrhotite zone up to 3 metres wide has developed on the Footwall of Alpha. Fluorite and tetrahedrite is also present. There is a broad biotite alteration zone surrounding Alpha and Phi, with sub-ordinate chlorite pseudomorphs after hornblende and massive biotite-pyrite-chlorite aggregates in mafic xenoliths.

The sub horizontal zone of supergene gold enrichment is immediately above the interface with the fresh rock at a depth of 50 to 80 metres. Over both zones is lesser pods of supergene gold mineralisation higher in the saprolite.

There is a broad Mg-Fe rich halo surrounding the mineralisation. Unaltered rocks contain paragonite, whereas in the Alpha and Phi lodes is muscovite.

The estimated resource is 6.3 Mt at 4.8 g/t for 895 000 oz.

The site at the time of writing had not been mined. It is several acres of highly disturbed ground from exploration. Several small historic deposits are in the immediate vicinity including Grafter and Big Four, which has seen minor historic development.

Other Regions, Features and Areas containing this locality

References