Final report on AN 457

Abstract

AN457 is situated within the highly prospective Proterozoic McArthur Basin, just to the south of the world class McArthur River (HYC) zinc&lead&silver deposit. The ground covered by Authorisations Northern (AN) 457 was formerly part of the MIM held AN366, but was relinquished in 1996 under statutory relinquishment requirements. The relinquished ground was then reapplied for by MIM as separate Authorisations, under identical legislative conditions as an Exploration Lease. Although the first application was lodged by Mount Isa Mines in mid 1996, hurdles in the application process meant the tenements (AN 455, 456 and 457) were not formerly granted until August 2006. AN 457 has been held by Mt Isa Mines for a period of 4 years commencing in 2007 and expiring in August 2010. A review of the MRM near mine exploration archive revealed a lack of data relating to the ground covered by AN 455, 456 and 457, ground formerly covered as part of AN 366. This prompted a search of the Minerals and Energy Information Centre (MEIC) archive, which revealed a large amount of historical exploration data covering the Amelia and Coxco Valley areas, dating back to 1957. The last significant reports accessed from the MEIC archive dated to the mid 1970's, meaning that known Mount Isa Mining Exploration (MIMEX) division reports from the early 1990's still had to be located. The physiographic features of AN 457 were found to be markedly different from AN455, as it covers ground along the Emu Fault Zone. The EFZ is marked by a prominent uplifted scarp of tectonised basal dolomite with interbedded dolosiltstone lithologies. A day as spent with a hand held GPS in establishing the corner lease boundaries of all three AN's and an overview of the work required for 2009 was undertaken. The ongoing critical shortages of Geoscientific staff throughout 2008 prevented the realisation of the proposed 2008 exploration programme. The additional obstacles of the sudden downturn in commodity prices in late November (which alone threatened to close the mine and which radically reduced 2009 budget expenditure across the site) and the temporary closure of the mine from 17th December to 20th February due to the Federal High Court's decision to uphold the Northern Land Council's claim against the project expansion, have continued to impact on MRM's ability to meet expenditure commitments outside of exploration work conducted on AN 366 during 2009. Ongoing critical technical staff shortages, exacerbated by the current economic downturn, have meant that expenditure commitments on the AN's were not met. A continuation of lack of resources from critical technical staff have unfortunately resulted in no expenditure on AN's 455, 456 and 457 over the 2009/2010 reporting period, resulting in a nil report.