Postgraduate Profiles

Andrew Lucas

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Thesis: Finding Gold in the Environment – Using Diffusive Gradients in Thin Films (DGT) to Evaluate Geochemical Anomalies of Gold in the Environment.

Gold is a precious metal that exists in the environment in extremely low concentrations (>1ppb). Any technique which is sensitive enough to usefully determine ultra-low quantities of metals such as gold is of interest to exploration geochemists and mining companies alike. The diffusive gradients in thin films (DGT) technique, which has been used extensively to monitor ultra-low concentrations of metals in soils, sediments and waters, is likely to be ideally suited for geochemical exploration of gold in the environment.

My research details the development of a DGT method for the geochemical exploration of gold, and introduces a new binding-layer based on activated carbon. To date, the results of this study show that the technique has significant potential to be used for the geochemical exploration of gold in aqueous environments. Further method development will be focused on the technique's potential for measuring different gold species including nanoparticles of gold. Developed methods will be applied in waters, soils and sediments.

Why my research is important

Gold has become increasingly difficult to find. During the last twenty years, around 50% of new ore discoveries in the circum-Pacific region have been in areas where the ore has been concealed by regolith, putting pressure on exploration geologists to examine alternative methods of detection. Considering that the regions of the world where regolith cover is prominent are also regions where gold mining commonly takes place, it is likely that techniques such as DGT, which potentially allows for detection of mineral anomalies, will assume greater significance in the field of exploration geology. In addition to DGT's application to exploration geochemistry, my research is likely to provide further insight into the mobility of gold in surface waters and it's bioavailability in soils.


DGT deployed

Jan 2010

Jan 2013