Inferred resource21,000 tonnes contained U3O8Westmoreland
This comprises the eastern end of a series of small prospects and deposits spread over about 50 kilometres straddling the Queensland - Northern Territory border, about 400 kilometres north of Mount Isa. Westmoreland is on the Queensland side of the border and its deposits extend over about 10 kilometres.
The first uranium mineralisation was discovered here in 1956, by a prospector with a Geiger counter. Late in 1956 the Bureau of Mineral Resources flew an airborne scintillometer survey and recognised anomalies in outcrops of the Westmoreland conglomerate held by Mount Isa Mines Ltd (MIM). Further work resulted in three mining leases being pegged over the Redtree deposit in 1959.
In 1967 Queensland Mines Pty Ltd obtained an exploration permit over the area surrounding the MIM-ZC leases and commenced a major drilling program which identified further Redtree deposits and the Huarabagoo deposit. In 1975 Queensland Mines formed a Joint Venture with Urangesellschaft Australia Pty Ltd, Anglo Australian Resources NL and IOL Petroleum Ltd, with the IOL share later being taken over by a CRA subsidiary. In the period 1976 to 1983 Urangesellschaft discovered the Junnagunna deposit while they were managing the Joint Venture. In 1985 Queensland Mines resumed management.
In 1990 CRA Exploration Pty Ltd (now Rio Tinto Exploration P/L) entered the Queensland Mines - Urangesellschaft Joint Venture and took over the exploration work with a view to earning equity in the Joint Venture. In 1997 Rio Tinto took over the whole project (it already had a 100% interest in the original MIM-ZC mining leases at Redtree), but relinquished the leases in 2000.
The main deposits comprise three mineralised pods adjacent to the Redtree Dyke and flat irregular masses further from it. Grades are 0.1-0.2% and 0.04-0.15% U3O8 respectively, with associated gold. The total inferred resource for Redtree, Huarabagoo and Junnagunna is about 21,000 tonnes contained U3O8. Three other prospects contain further small known resources. The "copper/gold/uranium" leases were apparently taken up by Tackle Resources after Rio Tinto relinquished them and in August 2004 the rights were bought by Canadian company Laramide Resources Ltd.