Search is on for signs of microbial activity isolated in Earth's crust.
15 May 2013
Water filtering out of the floor of a deep Ontario mine has been trapped underground for more than a billion years. It bubbles with gasses carrying nutrients that could sustain microbial life.
Scientists working 2.4 kilometres below Earth's surface in a Canadian mine have tapped a source of water that has remained isolated for at least a billion years. The researchers say they do not yet know whether anything has been living in it all this time, but the water contains high levels of methane and hydrogen — the right stuff to support life.
Micrometre-scale pockets in minerals billions of years old can hold water that was trapped during the minerals’ formation. But no source of free-flowing water passing through interconnected cracks or pores in Earth’s crust has previously been shown to have stayed isolated for more than tens of millions of years.
“We were expecting these fluids to be possibly tens, perhaps even hundreds of millions of years of age,” says Chris Ballentine, a geochemist at the University of Manchester, UK. He and his team carefully captured water flowing through fractures in the 2.7-billion-year-old sulphide deposits in a copper and zinc mine near Timmins, Ontario, ensuring that the water did not come into contact with mine air.