Partial relinquishment report for the period ending 14 September 2010

Abstract

This report covers the first relinquishment of EL 4171 which includes 110 blocks, or 53% relinquished. A remaining 96 blocks are to be retained for further exploration by Rio Tinto Exploration and joint venture partner, BHP Billiton. Exploration activity for the area relinquished from EL 4171 'Cato River' for the period of 12th September 2005 to 14th September 2010 is also summarized in this report. During the 1960's, BHP Ltd. conducted an extensive exploration program over east Arnhem Land in search for manganese and secondly bauxite following the discovery of Groote Eylandt. During this exploration program, three drill holes were completed within the area of relinquishment on EL 4171. Rio Tinto completed three air-core drill holes along a north-south trending track prepared for access to EL 4171 in 2007. Two air-core drill holes were completed by Rio Tinto Exploration on a south-west trending, pre-existing track between the Central Arnhem Road and the Dhalinybuy community. Results from the five holes were deemed non-bauxitic, with the highest value for Al2O3 being 29.9%. In a joint venture agreement with RTX, BHP Billiton has simultaneously explored the area of EL 4171 for manganese.