Surrender and final report for EL 23522, 26 February 2003 to 26 February 2006

Abstract

The East Alligator Exploration Licence (EL 23522) is located in West Arnhem Land approximately 280 km east of Darwin and has an area of 754 km2 (382 blocks). Cameco Australia Pty Ltd (Cameco) was granted the licence on 26 February 2003 for a period of 6 years. Cameco's exploration efforts within the licence have focussed on unconformity-style uranium mineralisation. This report outlines all exploration activity for the period from date of grant until full surrender on 25 February 2006. Work consisted of airborne geophysical surveys (magnetics, radiometrics, hyperspectral and TEMPEST electromagnetics), and outcrop sampling. Regional outcrop sampling was conducted across the tenement, designed to provide a broad, first-pass geochemical coverage of the project area. Sampling was also conducted within and marginal to a section of the Bulman Fault Zone and was designed to follow up on a broad zone of anomalous geochemistry. Other sampling targeted radiometric anomalies and hyperspectral targets. Values as high as 68.10 ppm U (U/Th=33.55) were recorded in Fe-rich Gumarrirnbang sandstone marginal to the Bulman Fault Zone. It is likely however the metal content has been inherited from the immediately overlying Gilruth Volcanics units, and is not related to any mineralising event in the area. Other geochemical results confirm an intimate association between elevated uranium and volcanic rocks or volcanic-derived materials, or sandstone samples proximal to volcanic layers. As such, elevated uranium values in surface samples map the distribution of residual volcanic material, but do not assist in defining a deeper level, basement-related target. The TEMPEST survey conducted in 2005 confirmed that the depth to the upper horizon of the Nungbalgarri Volcanics was in excess of 200m, with an inferred depth to the unconformity of Mamadawerre Sandstone and basement rocks in excess 450m. The depth to the unconformity, and lack of targets has downgraded the potential prospectivity of the licence area in respect to uranium mineralisation.