CSIRO and Australian Synchrotron researchers strike gold in a new Nature Communications article that highlights advances in mineral exploration.
Congratulations to Drs Mel Lintern, Ravi Anand, and Chris Ryan from CSIRO and Dr David Paterson from the Australian Synchrotron for their publication today in Nature Communications that describes how they used X-ray Fluorescence Microscopy at the Australian Synchrotron to find traces of gold and other metals in eucalyptus leaves.
In their research, the scientists sampled Eucalyptus and Acacia trees located ~30 m above gold deposits in Western and South Australia. The gold in these leaves is not visible to the naked eye, but found as "nuggets" about one-fifth the diameter of a human hair. The researchers used the Maia X-ray fluorescence detector (developed by CSIRO in collaboration with the Australian Synchrotron) on the XFM beamline to locate the gold within the leaves. The Synchrotron produced images of the gold, which would otherwise have been untraceable.
"Our advanced X-ray imaging enabled the researchers to examine the leaves and produce clear images of the traces of gold and other metals, nestled within their structure," Principal Scientist Dr David Paterson said. “The Maia detector is a fantastic Australian invention. Only by scanning about a 1000 times faster than any other X-ray microscope in the world, were we able to see these minute gold particles for the first time.”
The gold particles were found in highest concentrations in the leaves of the Eucalyptus trees, possibly because large quantities of gold are toxic to a plant and so are drawn to the extremities where they could be shed.
The proof that eucalypts can transport gold from deep beneath the ground through their root systems into the leaves is expected to generate great interest from within the gold mining and exploration industry, which spends billions of dollars per year searching for new deposits.
Former Newmont Mining Geochemist, Nigel Radford, says the implications for gold exploration are huge.
"A lot of this stuff has been speculated about for some time, but the identification of the gold particles in the leaf materials is completely convincing and very, very important for the future of mineral exploration," said Mr Radford, who has worked in mineral exploration his entire working life, most recently with US-based Newmont, one of the world's biggest gold mining companies.
Mr Radford believes it has the potential to make gold exploration much quicker and cheaper. "Ideally, any mineral exploration team would like to collect their samples on-surface," he said. "If you can sample on-surface, it saves all the cost and all the time involved in drilling holes."
X-ray fluorescence images showing (a) the distribution of copper (blue), strontium (green) and gold (red) in natural leaf specimen. (b) Detailed view showing isolated gold particles (red). Scale bars are 500 and 50 microns in (a) and (b) respectively.
For more details see the following CSIRO Media Release: