Reconnaissance stream sediment sampling for diamonds and metalliferous mineralisation, north Katherine River

Abstract

A helicopter-borne reconnaissance stream sediment sampling programme has been conducted within the proposed Kakadu National Park Stage 3 Extension and Conservation Zone for diamonds, gold, platinum-group elements (PGE) and base metals. A single diamond has been recovered from a bulk sample collected from Gimbat Creek, a tributary of the Katherine River. Other kimberlitic minerals have also been discovered. The source of these minerals has yet to be located and the area must be considered as having some potential for diamond deposits. Anomalous levels of cyanide-extractable gold have been detected in several creeks, including one result which would be considered as highly anomalous and worthy of immediate follow-up. Geologically the area is considered highly prospective for unconformity-style gold and PGE deposits. It should be emphasized that world-class deposits in the region such as the Jabiluka gold-uranium deposit may have quite subtle geochemical and geophysical features, requiring comprehensive and exhaustive exploration efforts to locate.