The time when gold was simply used as stored-value investments or ornamentation are over. Today, the applied uses of gold range from spacecraft thermal insulators to nanoparticles for cancer treatments. Now we also know that gold is not as environmentally stable as previously thought, but is continuously cycled like all other elements on Earth. Primary gold deposits are formed by orogenic and hydrothermal processes. Weathering of these sources results in gold dissolution forming soluble complexes and particles that can be transported and accumulated in enrichment zones or form secondary grains/nuggets. During these processes, gold migrates from high to low temperature environments. In doing so, changes in gold morphology, speciation and association with various minerals occur and are strongly influenced by the biosphere. Gold can be dissolved and re-precipitated by a range of microbes, some of which are equipped with gold-specific resistance responses.
While gold has been found in plants and animals, it ultimately ends up dissolved in the oceans and re-cycled into subduction zones. Peak gold may be upon us and finding new deposits poses greater challenges, especially in mature landscapes and with the number of high-grade, gold-bearing ores declining. This highlights the need to development new exploration methods and optimise metallurgical processes for gold extraction from ore, old tailings or recycled electronics. Gold mining can lead to numerous environmental and cultural issues including mercury contamination from artisanal mining practices and the circulation of illegal gold in global markets. Overall, national economies, mining companies and consumers need to take greater responsibility to prevent overstretching an already strained resource and should strive for sustainability. Therefore, in this session we invite papers from a wide range of disciplines studying gold, including mineralogy, geochemistry, economic geology, exploration geoscience, metallurgy, geomicrobiology, biochemistry, nanomedicine, archaeology and economy.|
Dr Frank Reith (Australia)
University of Adelaide
About the session convenor
Frank Reith obtained a PhD from the Australian National University (Australia) in 2006 for his pioneering work on the geomicrobiology of gold. From 2007 to 2015 he was an ARC Research Fellow at the School of Earth and Environmental Sciences, University of Adelaide (UoA). In March 2015 he was appointed as senior lecturer, and currently holds an ARC Future Fellowship in The School of Biological Sciences, UoA. He heads the Microbes and Heavy Metal Research Group at the Waite Research Institute, where his laboratory is co-located in CSIRO Land and Water since 2004.
Dr Reith’s research aims to understanding the interactions of microorganisms and trace metals in surface environments. He is leading a multidisciplinary research projects aimed at uncovering the fundamental mechanisms of biochemical, geobiological, and geochemical cycling of gold and other heavy/noble metals from individual cells to entire landscapes. From this fundamental understanding he aims to develop novel prospecting and processing technologies for the gold industry.
- Dr Jeremiah Shuster (Australia), University of Adelaide