2010 Annual group technical report MLN 2, MLN 3, MLN 951 - MLN 953, MLN 956 - MLN961, 1 July 2009 to 31 June 2010

Abstract

Groote Eylandt is Aboriginal-owned land, as granted under the Aboriginal Land Rights (NT) Act 1976. Groote Eylandt Mining Company Pty Ltd (GEMCO)'s obligations are chiefly embodied in various lease documents including Mineral Leases and Special Purpose Leases (SPLs), a Letter of Understanding dated 13 May 1965 and an Agreement dated 16 September 2006. Groote Eylandt is predominantly composed of a stable basement of Proterozoic quartz sandstones and quartzites. The overlying manganese deposits are part of a blanket of Cretaceous sediments lapping onto the western margin of the Proterozoic basement sandstones and quartzites of the McArthur Basin. The manganese orebody is a sedimentary layer, consisting of manganese strata occurring between clay and sand beds and gently undulates beneath the western plains of the island. It extends over an area of about 50 square kilometres as an almost continuous horizon ranging in thickness up to 11 metres. The ore body is thus essentially stratabound and strataform in character. The resource definition drilling program undertaken during FY10 (covering the period July 1 2009 to June 30 2010) year have been for the purpose of increasing confidence in the resource to measured category. A total of 1139 Reverse Circulation holes were drilled for a total of 30,996.5m in lease areas MLN 951, MLN 952, MLN 953, MLN 956, MLN 957 and MLN 959. 1051 holes intersected manganese. Aerial photography was carried out over all of the mining leases to facilitate annual reconciliations of stockpiles.