Geophysics and drilling collaboration final report for EL 27472 Larrimah East Project 2012

Abstract

The Western Desert Resources Limited (WDR) Larrimah East Project centred on EL 27472 east of Larrimah in the Northern Territory had two diamond core holes drilled in 2012 (12LE001 and 12LE002). The drilling was co-funded by the Northern Territory Government as part of the Department of Mines and Energy's Geophysics and Drilling Collaborations program. The project area overlies the non-exposed Palaeoproterozoic to Mesoproterozoic McArthur Basin, and possibly a northern extension of the Mesoproterozoic Beetaloo Basin, a sub-basin of the broader McArthur Basin. The targeted mineralisation was McArthur River-style sediment-hosted stratiform zinc-lead-silver in the organic parts of the Kyalla Member and the Velkerri Formation (Roper Group), with a secondary conceptual target being base metals hosted by Cambrian carbonates of the overlying Daly Basin. The drill holes targeted XTEM Airborne EM anomalies identified through a survey carried out by WDR in 2010 which was also co-funded by the Northern Territory Government. Drilling commenced on 16 September and finished on the 8 October 2012. Processing of the core was completed in early November. A commercial contractor carried out wireline logging of gamma, magnetic susceptibility, density, conduction, resistivity and deviation. A mafic volcanic/dolerite was composite-bulk sampled for chemical assay, as were selected features such as minor chlorite-quartz +/- pyrite veins. No significant assay results were recorded. There was no significant mineralisation encountered during the drilling and the source of Airborne EM anomalies targeted have not been explained. After penetrating recent cover and strongly weathered and loosely consolidated Cretaceous sediments, drilling intersected Cambrian Tindall Limestone, Antrim Plateau Volcanics, and upper Proterozoic Roper Group sediments. One of the targeted formations, the Kyalla Formation, was intersected in one of the holes. In the second drill hole the Antrim Plateau Volcanics are represented by a dolerite sill and thin flows of vesicular basalt. In part the dolerite is very coarse and includes potassium feldspar. Magnetite is disseminated throughout and there is significant alteration of plagioclase and pyroxenes to sericite. Parts of the dolerite contain trace levels of very fine pyrite and chalcopyrite. Six thin section samples were submitted to Pontifex and Associates.