The Mass of Microbes in Deep African Mines Lead Lives of Quiet Desperation Project Update uri icon

DCO ID 11121/1472-6756-4654-3355-CC

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  • The Witwatersrand Basin in southern Africa, one of the oldest geological formations on Earth, began as a shallow sea about 3 billion years ago. The Basin is home to extensive gold and diamond mining operations, where humans have dug some of the deepest mines in the world. These deep mines have been a boon to scientists as well. The mining companies drill boreholes into surrounding pristine rock, which intersect with fractures filled with groundwater. Scientists can analyze this water to probe the limits of deep life and to learn how microbes make a living when trapped kilometers beneath the surface.

    DCO Deep Energy and Deep Life Community members Thomas Kieft (New Mexico Institute of Mining and Technology, USA), Verena Heuer (University of Bremen, Germany), Esta van Heerden (University of the Free State, South Africa), Barbara Sherwood Lollar (University of Toronto, Canada), and Maggie C.Y. Lau and Tullis Onstott (both at Princeton University, USA) investigated the organic matter in fracture waters to find clues to how microbes live in these ancient rocks. The researchers sampled from mine boreholes reaching just over 3.4 kilometers deep and characterized the dissolved organic matter within. Their results paint a picture of isolated microbial communities eking out a living using dissolved hydrogen gas (H2) and inorganic carbon released by the rocks, with little or no input of organic carbon from the surface. The researchers report their findings in a new paper in the journal Organic Geochemistry.

    Read more here .