They say money doesn’t grow on trees but it seems gold does after researchers discovered tiny specks of gold in gum tree leaves in Kalgoorlie.
A study by CSIRO scientists, published today in the journal Nature Communications, found eucalyptus trees in the region were drawing up gold particles from metres below the ground.The results showed gold was being taken up by the roots of the trees before being deposited in leaves and branches.
Lead author and geochemist Mel Linter said the “golden leaves” could help uncover big gold deposits buried deep underground.
“Some of these trees are quite deep-rooted and provide us with a window into what is happening down under,” he said.
“If the results are high in the leaves, then clearly that gold has got to come from somewhere, so it is very likely you’re going to find a source beneath the trees.”
It is believed leaf sampling could be used as a more cost-effective and environmentally friendly mineral exploration technique than traditional drilling.
The technique can also be used to find other metals such as zinc and copper.
Dr Lintern said exploration companies that sponsored the research and had early access to the results, were already sampling leaves for gold.
“They are very cagey of their success or otherwise but we definitely know there are companies that are out sampling leaves,” he said.
“What we are dealing with in exploration now is trying to find the more difficult mineral deposits, so new techniques have to be developed.”
While it is possible to uncover significant deposits beneath eucalypts containing gold particles, the trees themselves can only take up small amounts of gold.
The research team used a powerful X-ray microscope at the Australian Synchrotron in Melbourne to find the particles.
Australian Synchrotron principal scientist David Paterson described it as a “needle in a haystack” search.
“The specks of gold we found in the leaves were very small,” he said.“If you scaled up one of these specks to be the size of a grain of sugar, what we have done is the equivalent of finding that
grain in an area the size of a football ground.”
Dr Paterson looked at about 25 leaves as part of the study and found gold particles in 70 per cent of them.