Virtually all of Australia's significant uranium deposits were discovered between 1969 and 1980 during the period of high expenditures on exploration for this commodity. This was followed by a long period of low exploration expenditures from 1982 onwards, during which only one deposit (Kintyre) was discovered. Estimates of Australia's uranium resources continued to increase after 1982 only because of on-going delineation of resources at the known deposits.
Australia's uranium resources at December 2000, within the Reasonably Assured Resources (RAR) category recoverable at US$40/kg U, were estimated by AGSO - Geoscience Australia to be 654 000t U. These resources are more than any other country has reported, to date, in this category. Most of these resources are in six deposits:
Olympic Dam (South Australia)
Ranger, Jabiluka, Koongarra in the Alligator Rivers region (Northern Territory)
Kintyre and Yeelirrie (Western Australia).
Australia has the world's largest (29%) resources in RAR recoverable at ≤US$80/kg U (includes resources in ≤US$40 category) with 667 000t U in this category. According to uranium resource figures published by the mining companies (as distinct from the OECD/NEA and IAEA resource categories defined in Appendix 1), more than 80% of Australia's uranium resources occur in two main types of deposits and about 97% are in four types of deposits:
Breccia complex deposits contain about 65% of Australia's total uranium resources and nearly all of these resources are at Olympic Dam, which is the world's largest uranium deposit.
Unconformity-related deposits account for about 20% of Australia's total resources, mainly in the Alligator Rivers field (Ranger, Jabiluka, Koongarra), and in one deposit in the Rudall Province, Western Australia (Kintyre).
Sandstone uranium deposits account for about 7% of Australia's total resources, mainly in the Frome Embayment field, South Australia (Beverley, Honeymoon, East Kalkaroo, Goulds Dam) and the Westmoreland area, Queensland (Redtree, Junnagunna, Huarabagoo). Other significant sandstone type deposits include Manyingee, Mulga Rock and Oobagooma in Western Australia, and Angela in Northern Territory.
Surficial (calcrete) deposits have about 5% of Australia's resources, most of which are in the world class Yeelirrie deposit. Other calcrete deposits include Lake Way, Lake Maitland and Centipede (Western Australia).
Other types of uranium deposits in Australia include metasomatite deposits (Valhalla, Skal and Anderson's Lode, Queensland) with approximately 1.5% of Australia's total uranium resources. Australia has only small resources within metamorphic (remnant resources at Mary Kathleen, Queensland), volcanic (Ben Lomond, Maureen, Queensland) and intrusive deposits (Crocker Well, Mount Victoria, South Australia). Australia has no significant deposits of the quartz-pebble conglomerate type, vein type and collapse breccia pipe type.
