The Tasmania mine at Beaconsfield was one of Australia's richest and deepest mines until its closure in 1914. The mine was worked to a depth of 450 metres and produced 800,000 ounces of gold. Following closure, the mine was allowed to flood and the surface collar of the shaft was affected by subsidence.
During the 1970s exploration drilling confirmed the continuation of the reef to at least 200 m below the old workings. By 1991 the old Hart Shaft collar had been re-established and dewatered to 160 metres. A change in ownership saw the project suspended and pumping stopped until 1992.
A program of deep drilling was undertaken during 1993 to upgrade the status of the resource estimates. This work was very encouraging, and since 1994 the Beaconsfield Mine Joint Venture has carried out drilling of the depth extension of the Tasmania Reef. A permanent stage pumping station at the 181 m level was commissioned in August 1995 and the water in the shaft was lowered.
A permanent winder and head frame were completed in January 1996 and the shaft was equipped to its final configuration in late 1996. A new ore treatment plant was constructed and commissioned during the 1999/2000 financial year.
Ore production recommenced during 2007/2008 after operations were suspended following a rockfall in April 2006, with a total of 141 000 tonnes being mined for the year. Gold production totalled 33,570 ounces.
Diamond drilling from surface has established that the reef continues to at least 650 m below the lowest level. Reported ore resources at 30 November 2007 comprised:
- Measured Resource: 307 000 tonnes @ 17.8 g/t Au
- Indicated Resource: 503 000 tonnes @ 15.1 g/t Au
- Inferred Resource: 63 000 tonnes @ 12.2 g/t Au
- Total Resource: 873 000 tonnes @ 15.8 g/t Au (446 000 ounces contained gold)
Further information on this mine is available at http://www.beaconsfieldgold.com.au/
