Millions of dollars’ worth of gold and silver found beneath volcanoes

In New Zealand, deep reservoirs teem with precious metals

hot spring

GOLD WATER  The magma that fuels New Zealand’s Champagne Pool hot spring (shown) heats deepwater reservoirs that are packed with millions of dollars’ worth of dissolved gold and silver, scientists have discovered. 

Jacob Surland/Flickr (CC BY-NC 2.0)

There’s gold in them thar volcanoes. Geoscientists have uncovered a mother lode of gold- and silver-enriched water in reservoirs inside a series of New Zealand volcanoes.

A shallow glob of magma heats water in the Taupo Volcanic Zone from below. The scalding water breaks down nearby rock and becomes loaded with dissolved metals such as gold and silver.

While subsurface rocks contain modest amounts of gold, researchers identified six water reservoirs hundreds of meters deep that brim with bling. Gold concentrations in the water topped 20 parts per billion and silver concentrations reached 2,000 or more parts per billion. Geoscientist Stuart Simmons of the University of Utah in Salt Lake City and colleagues report their findings in a paper to be published in Geothermics.

Tapping one of these water reservoirs could yield as much as $2.71 million of gold and $3.6 million of silver annually, the researchers estimate. Hopeful prospectors should note, however, that safe extraction may require the development of new mining technologies to avoid interfering with a way people are already tapping into the volcanoes’ riches: by converting their heat into electricity.

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