Annual report EL 25688 Mountain Creek NT to 23 September 2008

Abstract

EL 25688 Mountain Creek is in the West McArthur Basin, Northern Territory of Australia, entirely within the proposed Limmen National Park. It is about 40 kilometres south of the Roper River. The geology of the area is comprised of Proterozoic sandstones, siltstones and mudstones of the Moroak Sandstone, Velkerri , Kyalla Member and Chalmers River Formation. These are overlaid locally by Cambrian Antrim Plateau Volcanics and intruded by Proterozoic dolerite and diorite. The exploration objective was either an Unconformity-type Uranium Deposit similar to those of the Alligator River Province, or a palaeochannel deposit similar to the Honeymoon Well project in South Australia. In the Unconformity-type deposits, the uranium is associated with chloritised sandstone, while the palaeochannel deposits rely on uranium fixation by change of oxidation state with organic material. A review of available open-file information on the license was performed, seeking evidence to facilitate the exploration for uranium within the area. The most readily accessible data was airborne geophysics, geological mapping, mineral occurrence and topographic information. Airborne radiometric anomalies have been investigated on the ground, using a portable gamma ray spectrometer, an Exploranium GR135 Plus, and have been sampled for analysis where of interest. Most of the anomalies were associated with black soils, though two of them correlated with lateritic duricrust outcrops. Determinations of uranium, thorium and potassium were made using the gamma ray spectrometer, while rock chip samples were also investigated with a Niton field-portable XRF device. Soil geochemical samples were taken in areas that lacked outcrop, and submitted for ICP-MS multi-element assay. The reconnaissance ground radiometric and geochemical survey has shown that the airborne radiometric anomalies were mostly in brown and black soils. The uranium and thorium abundances were determined by ICP-MS to be a maximum of 5.54ppm for U and 7ppm for Th.