Three kilometres under the grassy plain of South Africa, pockets of age-old water lie trapped in the rock. The latest research suggests that these pockets of water might have been isolated for 2 billion years.
These liquid pocket – time capsules, if you will – are hot, salty, and devoid of nutrients from the surface. What’s astounding is that it may be chemically similar to water deposits on Mars.
Isolated from the environment for 2 billion years
Supported by funding from NASA and the National Science Foundation, the researchers collected samples in 2018 and 2019 by descending into a gold and uranium mine operated by Harmony Gold.
“There is a potential that [the pockets] were isolated over that long time scale. So this would be a unique opportunity to see life, essentially, evolving in a bubble”.Devan Nisson, a graduate student at Princeton University in New Jersey
The water lies in rock fractures accessed through boreholes, allowing the researchers to release some of the pressurised water and filter out material for analysis.
Nisson, who conducted the research with a team of scientists, presented preliminary finding during the AGU Fall Meeting of the American Geophysical Union in San Francisco.
The research paper, titled Organic Chemistry in a Potentially Ancient Hypersaline Brine: New Insights on the Limits of Microbial Life Inhabiting 3.1 km Deep Fracture Fluid in South Africa, can be viewed here.
Why this research is important
The research now presents an opportunity to characterise microbial life in these potentially ancient brines found SA mine, Moab Khotsong in North West, about 180 kilometers southwest of Johannesburg.
“When they examined the material under a scanning electron microscope, they saw rodlike shapes that appeared to be bacteria or similar-looking microbes called archaea. One of the cells was pinched in the middle, apparently in the process of dividing.”
Nisson and her colleagues examined the material under a scanning electron microscope but plan to extract and sequence DNA in order to verify whether the water contains living cells.
“Genetic data would also help reveal whether the cells are indeed creatures that have been isolated for billions of years, or whether they are more familiar microbes introduced when miners drilled into the chamber.”
- Devan Nisson, Princeton University
- Thomas L Kieft, New Mexico Institute of Technology
- Oliver Warr, University of Toronto
- Clifford C Walters, ExxonMobil Research and Engineering Company
- Esta van Heerden, North-West University
- Errol Duncan Cason, University of the Free State
- Julio Castillo Hernandez, University of the Freestate
- Jan-G Vermeulen, University of the Freestate
- Barry M Freifeld, Lawrence Berkeley National Laboratory
- Hiroshi Ogasawara, Ritsumeikan University
- Raymond J Durrheim, University of the Witwatersrand
- Barbara Sherwood Lollar, University of Toronto
- Tullis C Onstott, Princeton University
- Bennie Liebenberg, Independent Consultant