EL 25325 Yambah, Final Report

Abstract

EL 25325, comprising of 327 blocks, was applied for by Arafura Resources on 21/04/06. The area was selected by Arafura Resources NL because of the potential for secondary sandstone hosted type uranium mineralisation in unconsolidated Cainozoic basin sediments of the Burt Basin, derived by erosion of adjacent uraniferous basement granites and gneisses. The license was granted on 17 January 2007 and transferred to NuPower Resources Ltd in 14 March 2007 as a result of the demerger of Arafura's uranium assets into the newly formed company focussed on uranium. The Yambah tenement is underlain by basement rocks of the Aileron Province comprising greenschist to granulite facies metamorphic rocks with protolith ages in the range 1865-1710 Ma. It forms part of the North Australian Craton and is geologically continuous with the gold-bearing Tanami and Tennant Regions to the north. NuPower carried out an airborne electromagnetic (AEM) survey in June-July 2007 over the western two-thirds of the area as part of a larger survey of Nupower's tenements in the Aileron region, designed to explore for buried palaeochannels at the base of and within the Cainozoic sedimentary package as potential hosts for secondary uranium. Concurrently water from station stock water bores was sampled and assayed for a suite of major and trace elements the results of which are expected to assist with targeting potential sites of uranium accumulation within the palaeochannel systems. Final results from the AEM survey show that the technique successfully identified sections of several major palaeochannels in the license area and interpretation and modelling of the results has been completed, revealing that the Tertiary palaeodrainage is far more extensive and better developed than previously thought. Shallow palaeochannels draining northwards off the MacDonnell Ranges occur in the eastern part of the tenement, whilst more substantial palaeochannels occur in the west of the tenement and form part of the eastern half of the Burt Basin. NuPower also participated in the NTGS collaboration regional gravity survey over the Central Arunta region, for which the data is available. NuPower completed four rotary mud drillholes for a total of 504m on Yambah in 2008 using the 2007 AEM data to assist in siting the holes. Tertiary sediments were intersected in all holes, thereby validating the airborne EM data. No significant reduced horizons were intersected in the 'Canteen' palaeochannel developed on Yambah. Relogging of Mistake Bore indicated anomalous gamma and whilst situated outside the margins of the Canteen Palaeochannel, one hole was drilled to investigate this anomaly that intersected anomalous gamma within sediments. This drill hole was later logged using a Prompt Fission Neutron (PFN) tool which indicated that no significant amounts of anomalous uranium was present. Groundwater assays from station bores and NuPower drill holes reported previously, were found to be erroneous. These samples have been re-assayed and reported again in the 2010 annual report. No work was done in 2011 or in 2012.