2017 Annual Technical Report ML 31219 and ML 31220 reporting period 4 August 2016 to 3 August 2017

Abstract

Groote Eylandt is Aboriginal-owned land, as granted under the Aboriginal Land Rights (NT) Act 1976 (ALRA). The Groote Eylandt Mining Company Pty Ltd (GEMCO) has its obligations defined in various lease documents including Mineral Leases and Special Purpose Leases (SPLs), a Letter of Understanding dated 13 May 1965 and the Western and Eastern Leases Mining Agreements, both dated 17 May 2016. 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. This report covers what is commonly referred to as the 'Eastern Leases', the two mining leases (ML 31219 and ML 31220) that are located east of the main mining leases. Granted in August 2016, these licences cover the areas previously held by GEMCO under Exploration Licences in Retention ELR 28161 and ELR 28162 respectively. No drilling was conducted during the reporting period. Work associated with environmental approvals and pre-mining commitments were progressed. Baseline environmental monitoring of groundwater and surface water sampling sites continued.