Relinquishment report for EL 23045 'Rodinga', year ending 2 September 2005

Abstract

Exploration Licence 23045 'Rodinga' (EL 23045), is located in the southeastern sector of the Amadeus Basin in the Northern Territory. The Amadeus Basin covers approximately 150,000 km2 and is located in the southwestern part of the Northern Territory extending into Western Australia. It is comprised of a Neoproterozoic to mid-Palaeozoic succession of shallow marine sediments and attains a thickness of up to 14,000 m. The purpose of this report is to detail exploration conducted on the relinquished blocks of EL 23045 during the year ended 2 September 2005. The Chandler Formation is the primary target for potash mineralisation. In the eastern part of the Amadeus Basin, the Chandler Formation contains thick sequences of evaporitic rocks. Halite beds range in thickness from less than 50 m to over 1,000 m and average 470 m thick in the Rodinga area. These thickness variations are accentuated in areas of structural thickening due to salt tectonics. Within the Rodinga project area the Mt Charlotte No1 well intersected a 225 m thick section of Chandler Formation halite from 710 metres depth to the bottom of the hole and the Bluebush No1 well intersected 690 m of halite from 786 metres depth. These intersections occurred between depths of 700 and 1,500 m, within the depth range of economic exploitation. The Chandler salt has high bromine levels that suggest precipitation from late stage brines which is a positive indicator for the presence of potash salts. The main Chandler Formation target interpreted from seismic surveys in the Rodinga Project is a basinal depression target at Camel Flats, just north of Bluebush No1. Other targets are areas of thickening of the Formation in diapers and basinal depressions adjacent to salt diapers and salt walls derived from the underlying Bitter Springs Formation. Potential exists for large flat-lying Canadian-type potash deposits as well as diapir related European-style potash deposits.