12 July 2013

Dr Greg Holland explains why the discovery of billion-year-old water deep underground could hold clues to life on Earth, and on Mars.

Billion-year-old water could hold clues to life on Earth and Mars
Scientists have discovered some of the oldest water on the planet, which might contain microscopic life that has evolved totally separately from species on the surface of the planet.
A UK-Canadian team of scientists, including Dr Greg Holland from Lancaster Environment Centre, located water in fissures in rock at the bottom of a Canadian mine. The water, isolated from the surface for billions of years, contain abundant chemicals known to support life.
The findings, published in Nature, may force us to rethink which parts of our planet are fit for life, and could even offer clues about how life could exist on Mars.
“It’s astonishing that, when you drill a new borehole, water that has been sitting there for half the history of the earth freely flows out of the rock,” said Dr Holland, a lecturer in Isotope Geochemistry and lead author of the study. Dr Holland worked with researchers from the universities of Manchester, Toronto and McMaster to analyse the water leaking out of boreholes 2.4 km underground.
Using ground-breaking techniques developed at the University of Manchester, the researchers show that the fluid is at least 1.5 billion years old, but could be significantly older and has the capacity to support life.
They found that the water is rich in dissolved gases like hydrogen and methane and also in noble gases such as helium, neon, argon and xenon. It is the different forms – called isotopes – of noble gases that provide the evidence for the ancient ages.
The hydrogen and methane come from the interaction between the rock and water. These gases can provide energy for microbes, allowing them to exist indefinitely without energy derived from the sun. There is as much hydrogen in the water as around hydrothermal vents in the deep ocean, many of which teem with microscopic life.
While the study shows this ancient water could contain life, work is now underway to discover whether it actually does.

‘Our Canadian colleagues are doing the microbial analyses now, trying to find out if the water contains life,” said Dr Holland. “If it does, and these microbial life forms have been isolated for several billion years, the possibility exists that life maybe have evolved deep beneath our feet, entirely independent from life at the surface.”
Whatever the outcome of this next stage in the research, the results are already significant.
“Even if there isn’t life in this water, what we can be sure of is that we have identified a way in which planets can create and preserve an environment friendly to microbial life for billions of years,” Dr Holland explains. “This is regardless of how inhospitable the surface might be, opening up the possibility of similar environments in the subsurface of Mars.”
Project director and co-author, Professor Chris Ballentine of the University of Manchester, believes that the work may also have important implications for research around climate changing gases.
“The ground-breaking techniques we have developed at Manchester to date ancient waters also provide a way to calculate how fast methane gas is produced in ancient rock systems globally. The same new techniques can be applied to characterise old, deep groundwater that may be a safe place to inject carbon dioxide.”
David Willetts, UK Minister for Universities and Science, says: “This is excellent pioneering research. It gives new insight into our planet. It has also developed new technology for carbon capture and storage projects. These have the potential for growth, job creation and our environment.” The work was funded by NSERC Discovery and CRC grants, a NERC grant and Deep Carbon Observatory (DCO) support.
Dr Holland, who moved from Manchester to Lancaster Environment Centre in 2010, is currently setting up a laboratory for fluid analysis, with the focus on noble gases.