REGOLITH SYSTEMS PROCESSES: A COLLABORATIVE RESEARCH INITIATIVE IN AUSTRALIA

The regolith develops at the interface between the geosphere, hydrosphere, biosphere and atmosphere, and includes saprock, saprolite, various ferruginous crusts, sediments, soils, and ground or surface water - everything 'between fresh rock and fresh air.' Complex interactions between minerals, amorphous matter, water, and organisms over extended geological time can produce a range of materials that are significantly different from the original ones. In fact, weathering processes produce more fundamental chemical changes than any of the other geological processes (igneous, metamorphic or sedimentary).

To tackle the problems brought about by intense weathering in Australia, a number of core organisations have been brought together since 1995 under the Australian Commonwealth Government's Cooperative Research Centre (CRC) program. These include universities, federal government research organisations, state government agencies and industry representatives. Research has been geared towards both fundamental and applied issues. Identification and mapping of regolith materials are important first steps, and are commonly followed by geochemical and mineralogical characterisation. Some studies have looked at the geochemical and/or isotopic composition of groundwater, surface and rainwater, biological soil crusts, plants, etc. Palaeomagnetism and Ar-Ar methods have been used to date regolith processes. Thermochronological studies using apatite fission tracks have assisted landscape evolution interpretations. A vigorous education and training activity is being carried out for students and professionals, and a glossary was prepared to unify regolith terminology.

The regolith-related issues tackled by the CRC during the past five years have related mostly to mineral exploration in regolith-dominated terrains, where the emphasis has been on helping to explore through transported cover and to advise on new or improved sampling media or methods. Renewed funding for the CRC will see diversification over the coming seven years into the environmental arena, including salinisation of agricultural soils and groundwater, and into microbiological processes.