Curnamona Uranium Project
The Curnamona project derives it's name from the Curnamona Craton (a Precambrian terrane) that underlies the area of the Frome Embayment and several basins (from Cambrian to Tertiary in age). The craton and these basins, including the Callabonna Sub-basin, also straddle the SA-NSW border. The Callabonna Sub-basin, host to all the known sandstone uranium mines, has been the focus of all the Companies exploration to date. The Callabonna Sub-basin overlies the Eromanga Basin that in turn overlies the Precambrian basement.
Review of past activities
The Company has largely divested the Curnamona Project in July 2012 after some 5 years of exploration. Between 2007 and 2012 the project was focused in the north-east and central Frome Embayment targetting sandstone hosted uranium by flying very large Airborne Electromagnetic surveys (AEM) and drilling over 100 reconnaissance holes. This was a very ambitious project and a pioneering effort in this part of the basin; with the Company managing exploration over some 6000km2. The effort was aimed at locating a regional REDOX boundary in the basin and, had it succeeded, the pay off would have been substantial. To date no one has located the regional REDOX zone, where one would expect the largest deposits to occur. This has been a tightly held area and somewhat disappointing for a range of small and large companies working here since 2005.
The last drilling by the Company was completed in October 2011 with 26 holes totaling 2,500m on its Curnamona South project (EL 4586) and 3 holes for 420m on its Curnamona North project (EL 3844). A number of old drainage channels were targeted as potential hosts for uranium internalization. The drilling encountered anomalous uranium in two holes, CUS012 and CUN055, however levels were insufficient to warrant further follow-up. All drill sites were rehabilitated and in July 2012 the decision was made to divest the tenements to Renaissance Uranium Limited.
In July 2012 Callabonna Uranium Limited and Renaissance Uranium Limited (ASX: RNU) executed a binding agreement for the sale of ten exploration licenses (EL’s 3841, 3842, 3844, 3845, 3846, 4584, 4585, 4586, 4672, 4823) in the Frome Basin and one exploration license in the Northern Gawler Craton (EL 4640) for a consideration of 800,000 ordinary shares in Renaissance Uranium. Completion of the transaction is subject to customary conditions including ministerial consent pursuant to the South Australian Mining Act (1971).
Presently the Company retains only two tenements owned 100% in the Curnamona Project. EL4582 and EL4583 over magnetic features on the Benagerie Ridge. This area of granitoids and volcanics is of comparable age and geology to the Gawler Craton, about 1580 Ma and part of a regional felsic igneous province.
The interest lies in the magnetic features of the basement never previously tested and occurring below the Eromanga Basin at depth exceeding 200m. The potential is for Iron Oxide U-Cu-Au style deposits generally similar to Olympic Dam. However we now know that mineralisation associated with this style has a lot of variants including gold and and even epithermal silver.
The Company is presently in negotiations with a party to transfer these tenements on the basis Callabonna retains the future option to explore the basement (defined as all strata below the Eromanga Basin) on a 50/50 JV arrangement. These negotiations are yet to be finalised and completion of the transaction would be subject to customary conditions including ministerial consent pursuant to the South Australian Mining Act (1971).
Location of EL4582 and 4583 on a magnetic image of the basement. The tenements are centred on the northern Benagerie Ridge that is about central to the Curnamona Craton.