Trees mark the spot of buried gold

Traces of treasure in eucalyptus tree leaves may signal a hidden trove of gold under the surface, according to a new study.

Researchers have previously noticed small amounts of the precious metal in and around eucalyptus trees, but they didn’t know if the plants were soaking up gold from the ground or from windblown dust. Geochemist Melvyn Lintern of the Commonwealth Scientific and Industrial Research Organization in Kensington, Australia and colleagues used X-ray imaging to tally the tiny bits of gold in eucalyptus trees growing near and on top of buried gold in Western Australia.

Only trees growing directly over the 35-meter-deep deposit tapped into the gold with their deep-growing roots, the team reports October 22 in Nature Communications.

Because gold may be toxic to plants at high concentrations, the researchers think the trees push the shiny cargo from their roots to their extremities, such as leaves and bark, which amass the metal and eventually fall to the ground. The team suggests that the telling traces of gold on and around eucalyptus trees offer a new way to locate hidden treasure.