Mulga Rock

WESTERN AUSTRALIA

Mulga Rock, sometimes referred to as Officer Basin, is located in the Mount Margret Mineral Field in Western Australia. The deposits are located on the edge of the Great Victorian Desert 250kms north east of Kalgoorlie in the Shire of Menzies. The uranium deposits were discovered in 1978.

This paleao-channel uranium deposit area is covered by a number of tenements both of mining (ML) and exploration (EL) status, established for the purpose of uranium mining extraction and development.

The environment
Uranerz, the former explorer of the area and susidary of Uranerzbergbau of West Germany along with PNC (Power Reactor and Nuclear Fuel Development Corporation of Japan) are responsible for the thousands of kilometres of exploration cutlines, cleared drill sites, roads and access tracks, crisscrossing this desert region which includes the Queen Victoria Spring Wildlife Sanctuary, Class A Flora and Fauna reserve (A30491), just to the north of the Cundeelee Aborigional Community.

Exploration history
Uranerz previously had significant EL’s over the area covering 2000 sq kms, these were subsiquently taken over by Western Mining and Aztec Mining Company though non of these are active in the area at this time.

PNC origionally held 1,200 sq kms of the Officer basin area under EL’s. In August 1985, the Labor Government’s State Minister for Minerals and Energy, approved the upgrading of PNC’s EL’s to 10 ML’s covering a total area of 40.4 sq/km, these have since been reduced to the 9 listed above. This gave the Japenese Governments company PNC, secure tenement over these uranium deposits until 14th August 2006, these leases are even then renewable.

The deposits
Over the years many Japanese geologists have been brought into work on these deposits. It is reported that a "pre-JORC" estimation of 13,000 tonnes of U3O8 in 10.8 million tonnes of rock at an average grade of 1.2kg/t U3O8 exists across these tenements. The uranium mineralisation is between 20 to 30 metres in body. Two EL's have been applied for by Acclaim Exploration NL, that cover areas to the NW and SE of PNC's tenements of Shogun, Ambassador and Emperor. These Acclaim tenements cover a total area of 383 sq km.

Very little has been published by PNC (Power Reactor and Nuclear Fuel Development Corporation of Japan) about their activities, but we do know that in 1983 they dug an exploration pit 30 metres deep and 200 metres long. Uranium ore was removed from this pit, packed into 44 gallon drums and transported back to Japan for further treatment and testing.

PNC remediated the site at some time during the late 1990s, having filled in and rehabilitated the trenches. In 2000, Eaglefield began aquiring the tenements and conducting pre-feasibility work.


Produced 17 March, 1998
Updated August 2005

Mulga Rock in Brief