REGOLITH GEOCHEMISTRY, MINERALOGY, REGOLITH MAPPING, GEOMORPHOLOGY

The Cooperative Research Centre for Landscape Environments and Mineral Exploration (CRC LEME) is made up of researchers from Australian universities, Commonwealth and State Government geoscientific and environmental agencies, and private industry. CRC LEME aims to develop a greater understanding of Australia’s regolith terrain when applied to mineral exploration and environmental management. CRC LEME has ongoing projects throughout Australia, and this poster highlights some of the aspects of the projects within the State of New South Wales (NSW) that pertain to mineral exploration. Regolith, encompassing soils, sediments and weathered bedrock, mantles most of Australia, with significant depths (50-200 m) over much of the continent. In NSW CRC LEME’s mineral exploration projects are within the geological fold belts or on their perimeters with surrounding basins. Areas are selected so as to study various aspects of the distribution of regolith materials, their present and palaeo landscape position, their processes of formation, and their geochemical and mineralogical character. By placing the geochemical and mineralogical attributes in context of the evolving regolith architecture of an area, background versus anomalous values can be understood. In situ geochemical anomalies can be distinguished from transported anomalies, and the source of transported anomalies may be able to be inferred by interpreting palaeo groundwater flow in terms of a landscape evolution model. Certain regolith materials can concentrate minerals, eg. calcrete concentrates gold in the semi arid areas of NSW, and so are used as sampling media to target mineralisation. Studies of regolith profiles help to identify bedrock lithology, distinguish bedrock alteration from weathering, distinguish primary mineralisation from secondary mineralisation, and identify associated pathfinder elements.