Curnamona Uranium Project
The Curnamona Project is 100% owned by Callabonna Uranium Limited and comprises two largely contiguous areas of exploration licenses covering a total of 7,051km² making Callabonna Uranium the largest single ground holder in the Frome Embayment.
Curnamona North comprises nine exploration licenses totalling 4,514 km² in area. Curnamona South currently consists of six exploration licenses covering 2,537km² in area.
The Curnamona Projects are located in the Frome Embayment on the structural margin of the Curnamona Craton in South Australia about 50 to 100 km northeast of the Beverley Mine. At the Curnamona North Project, Callabonna Uranium is one of the first to systematically explore the Frome Embayment where it overlaps the northeast tectonic margin of the Curnamona Craton in faulted contact with the interpreted undercover extension of Mt Painter Inlier. This is a geological setting comparable to the Beverley uranium mine and Beverley Four Mile. The company is primarily exploring for sandstone “roll-front” style uranium deposits in Tertiary palaeochannels of the Callabonna Sub-Basin in the Frome Embayment.
The project areas cover large untested areas of comparable geology to all other Frome Embayment sedimentary style uranium deposits including the Beverly Mine, Beverley Four Mile, Honeymoon, Oban, East Kalkaroo and Gould’s Dam deposits. Important strata layers include the Tertiary Eyre and Namba Formations which are correlated throughout the Callabonna Sub-basin and are also found at the Curnamona North and South Projects.
Other suitable conditions apparent at Curnamona include a local source of uranium, buried depositional channels, reduced marginal host sediments and an active tectonic margin. The basement rocks of the Curnamona Craton and Mt Painter Complex are relatively enriched in primary uranium and over time oxidised groundwater dissolved the uranium and carried it down ancient drainage channels into the Frome Embayment with other erosional sediments. Soluble uranium in the groundwater continued to flow through the permeable sands until mixing with reduced materials. At this reduced-oxidised interface the mobile uranium was chemically precipitated and deposited as a secondary uranium mineral in “roll-front” style deposits. Regional faulting may also have enhanced roll-front mineralisation by redirecting and trapping palaeochannels forming further enriched redox zones.
Conceptual Cross Section - Callabonna's Tenements
Callabonna Uranium has completed a high-resolution airborne Electro-Magnetic (REPTEM) survey over the Curnamona North Project (3,400 line kilometres) to identify buried palaeo-channels. This survey successfully delineated what are interpreted to be well developed palaeo-channels that have not previously been tested.
Following on the success of the initial Airborne Electro-Magnetic (AEM) survey over Curnamona North, it is intended that Curnamona South will also be covered by a large AEM Survey to delineate palaeo-channels for drill testing. Rotary mud drilling and downhole geophysical logging is planned for late 2009.
