More than 66% of Australia is difficult to explore for mineralisation because of thick and complex regolith that formed because of wet conditions during the late Mesozoic and early Tertiary. During the Quaternary, there was a return to arid conditions and development of aeolian deposits that also obscure prospective mineralised basement lithologies. During the last 100 years, the depth to discovery of new mineral systems has increased to >700 m, exploration costs have increased and mineralised targets have been missed.  As a result, it has been necessary to develop techniques to increase the effectiveness of exploration. One such approach involves improving the depth resolution of geochemical sampling.

In this seminar, I will review the dispersal mechanisms by which metal anomalies are transported through regolith.  I will then discuss two case studies relevant to gold exploration: (1) calcrete geochemistry in the Gawler Craton and (2) spinifex biogeochemistry in the Great Sandy Desert near Telfer gold mine in Western Australia. I will conclude by showing that spinifex biochemistry is also relevant in lithium exploration to discover buried LCT (lithium-bearing) pegmatites in the Pilbara region of Western Australia. Lithium is now in high demand for battery manufacturing and is regarded as the new gasoline.

Presented by Emeritus Professor Ken Collerson, PhD, FAusIMM

Venue

Room: 
315, Level 3, Steele Building (#3), St Lucia campus