Integrated studies of soil, termites, vegetation and groundwater to understand metal migration at the kintyre U deposits, Western Australia
Geological Society Publishing House
Place of Publication
Office of Research and Innovation
Transported cover is a persistent problem for mineral exploration in Australia and elsewhere in the world. Explorers are not confident in the current understanding of where, when, and how geochemical anomalies form (or don’t form) in the cover and how to make the critical interpretive link to buried mineral deposits. Understanding how elements move through transported cover and their link to buried mineralization is increasingly important for exploration success in many regions of the world. At the Kintyre U deposits, groundwater, regolith, soil, Triodia basedowii (spinifex), Acacia ancistrocarpa foliage and litter, and termite (Nasutitermes triodiae) mound materials were sampled and analysed to test if near surface methods can detect mineralization through <1 to 80 m of cover. Near surface soil geochemistry, biogeochemistry and hydrogeochemistry weak anomalies did not correlate with primary mineralization through cover except in residual subcropping zones and the thin (<5 m) cover adjacent to these sites. Termite mounds, and to a lesser degree, A. ancistocarpa appear to reflect the mineralized signature in shallow cover (<10 m). A postulated metal migration model for this site links mechanical and chemical weathering and surface colluvial/alluvial down-slope dispersion, with U migration from the Kintyre Hill outcrop to the near surface environment. Plants, soils and groundwater are most likely cycling (near-background levels of) U in the cover at Kintyre. In shallow cover, plants and termite mounds are potential viable sample media. However, for exploration on sites with deep heterogeneous cover, geophysical responses or other new techniques will need to be developed to provide a traceable surface signature.