Scientists from the CSIRO have found that eucalyptus trees in the Kalgoorlie region of Western Australia are drawing up gold particles from the earth via their root systems and depositing it their leaves and branches.
Their findings have been published in the journal Nature Communications.
Geochemist at CSIRO, Mel Lintern said the eucalypt acted as a hydraulic pump – its roots extending tens of metres into the ground and drawing up water containing the gold.
“As the gold is likely to be toxic to the plant, it’s moved to the leaves and branches where it can be released or shed to the ground," Dr Lintern said.
"The leaves could be used in combination with other tools as a more cost effective and environmentally friendly exploration technique."
He said that while the traces of gold are only about one-fifth the diameter of a human hair, they could provide opportunities for mineral exploration, as the leaves or soil underneath the trees may indicate gold ore deposits buried up to tens of metres underground and under sediments that are up to 60 million years old.
"By sampling and analysing vegetation for traces of minerals, we may get an idea of what’s happening below the surface without the need to drill. It’s a more targeted way of searching for minerals that reduces costs and impact on the environment,” Dr Lintern said.
"Eucalyptus trees are so common that this technique could be widely applied across Australia. It could also be used to find other metals such as zinc and copper."
The full paper can be accessed at this PS News link.
Edition 385, 29 October 2013