Regolith mapping for geochemical exploration in the Yilgarn Craton, Western Australia

Abstract

A sound knowledge of the character and distribution of regolith materials within landscapes, as well as the underlying geology and mineralization, is vital in any comprehensive exploration program. The fundamental techniques used in regolith mapping in Australia can be traced to mapping in the Yilgarn Craton between the early 1980s and the early 1990s. Regolith mapping techniques have subsequently developed beyond the basic, well-established inventory concepts as a result of improved methodologies over the last twenty years. Regolith mapping now routinely involves multi-dataset integration and analysis of field data within a GIS framework. Landsat Thematic Mapper, HyMap™, radar, gamma ray spectrometry, magnetic surveys, airborne electromagnetic surveys (AEM), geochemistry, geological data and digital elevation models (DEM) are becoming standard datasets consulted during the production of regolith maps. Regolith mapping has been influenced directly by its association with geochemical exploration in the Yilgarn Craton of Western Australia. Regolith maps and databases now routinely include information about the nature and distribution of geochemical sample media, such as for example, surface lag. For printed maps, geochemical sampling-media information is provided directly through inclusion in a standard legend with overprint patterns, a custom legend, or a custom thematic map derived from the initial map data where a variety of styles can be available to show any potential sampling media.