A squad of scientists, led past times the University of Toronto’s Barbara Sherwood Lollar, has mapped the place of hydrogen-rich waters establish trapped kilometres beneath Earth’s surface inwards stone fractures inwards Canada, South Africa too Scandinavia. Common inwards Precambrian Shield rocks — the oldest rocks on globe — the ancient waters bring a chemical scientific discipline similar to that establish almost deep sea vents, suggesting these waters tin back upwardly microbes living inwards isolation from the surface.
The study, to last published in Nature on Dec 18, includes information from nineteen dissimilar mine sites that were explored past times Sherwood Lollar, a geoscientist at U of T’s Department of globe Sciences, U of T senior query associate Georges Lacrampe-Couloume, too colleagues at Oxford too Princeton universities.
The scientists too explicate how 2 chemic reactions combine to create substantial quantities of hydrogen, doubling estimates of global production from these processes which had previously been based exclusively on hydrogen coming out of the sea floor.
“This represents a quantum alter inwards our agreement of the full book of earth’s crust that may last habitable,” said Sherwood Lollar.
“Until now, none of the estimates of global hydrogen production sustaining deep microbial populations had included a contribution from the ancient continents. Since Precambrian rocks brand upwardly to a greater extent than than lxx per cent of the surface of Earth’s crust, Sherwood Lollar likens these terrains to a “sleeping giant,” a huge expanse that has right away been discovered to last a root of possible liberate energy for life,” she said.
One process, known every bit radiolytic decomposition of water, involves H2O undergoing a breakdown into hydrogen when exposed to radiation. The other is a chemic reaction called serpentization, a mineral alteration reaction that is mutual inwards such ancient rocks.
This written report has of import implications for the search for deep microbial life. Quantifying the global hydrogen budget is telephone commutation to agreement the amount of Earth’s biomass that is inwards the subsurface, every bit many deep ecosystems comprise chemolithotrophic — so-called “rock-eating” — organisms that swallow hydrogen. In the deep gilded mines of South Africa, too nether the sea, at hydrothermal vents where breaks inwards the cleft of Earth’s surface that release geothermally heated waters — hydrogen-rich fluids host complex microbial communities that are nurtured past times the chemicals dissolved inwards the fluids. This written report identifies a global network of sites amongst hydrogen-rich waters that volition last targeted for exploration for deep life over the coming years.
Further, because Mars — similar the Precambrian crust — consists of billions-of-year-old rocks amongst hydrogen-producing potential, this finding has ramifications for astrobiology. “If the ancient rocks of globe are producing this much hydrogen, it may last that similar processes are taking house on Mars,” said Sherwood Lollar.
Other telephone commutation members of the query squad are Chris Ballentine of Oxford University, Tulis Onstott at Princeton University too Georges Lacrampe-Couloume of the University of Toronto. The query was funded past times the Canada Research Chairs program, the Natural Sciences & Engineering Research Council, the Sloan Foundation Deep Carbon Observatory, the Canadian Space Agency too the National Science Foundation.