Annual report EL 4716, Mount Gates NT, year ended 26-02-1986.

Abstract

This report outlines the methods and results of an exploration programme conducted by CSR Limited over EL 4716, near Katherine, NT. The programme was conducted during the 1985 Dry Season at the sole expense of CSR Limited. It included an airborne radiometric/magnetic survey, soil, stream sediment and rock-chip geochemistry and diamond drilling. In March 1985, an airborne geophysical survey was undertaken by CSR Limited with the object of defining structurally prepared zones within the Maud Dolerite. Geological mapping and aerial photographic interpretations were completed to define areas of Maud Dolerite. The Maud Dolerite was found in two separate areas, Mount Gates and a valley centred at AMG 84O6,000mN and 222,000mE. Petrographic studies were undertaken to determine styles of alteration and rock types. Intense carbonate alteration was found in both locations. An orientation soil sampling programme was conducted over the Mount Gates grid and included size fraction analysis, soil and anthill sampling. The conclusion from this sampling was that minus 80 mesh soil sampling was the most cost effective technique for exploring areas of dolerite-derived soils. A stream sediment sampling programme was undertaken over areas of Maud Dolerite. The results of this bulk stream sediment programme showed two main areas of anomalous gold in stream sediments - Mount Gates and the valley to the south of Mount Gates. Limited follow-up work has assisted in defining these areas. Two diamond drill holes, totalling 250 m, were completed near Mount Gates with the intention of intersecting the anomalous gold zone at depth. No significantly anomalous gold was intersected in the drill holes, although petrographic examinations of the drill core revealed phyllosilicate and carbonate alteration. Further exploration is recommended in the valley south of Mount Gates where highly anomalous stream sediment values have been detected. Little potential for gold mineralisation was found over Mount Gates and future exploration within the Maud Dolerite will depend on results obtained from the nearby Maud Creek Goldfield.