Micro-organisms are found in every conceivable environment on modern Earth, as long as water is present and the temperature is below 122°C. Beyond the environmental and societal implications, this adjustment to various extreme circumstances raises the question whether extant life also occurs at great depths in the Earth’s crust, how life originated and evolved early in Earth’s history, and whether life may have originated on early Mars and elsewhere.
The “Géobiosphère actuelle et primitive” (GAP) research group is specialized in the characterization of the interactions between microorganisms and minerals. We developed numerous and innovative methods to jointly image and identify organic matter/microorganisms and their mineralized environment at the same micrometer scale. These developments benefit from a dedicated technical platform that allows preparing, imaging, and characterizing geomicrobiological samples in 2D and 3D. We have now a strong expertise in the in situ characterization of organic matter that permits to track down traces of microbial life in rocks, to characterize their microhabitats and to establish new types of biomarkers such as remnants of cells or biominerals.
Altogether, this allows us to conduct pioneering research in the framework of international collaborative research programs that mainly focuses on the study of the first traces of life on Earth and the diversification of microbial metabolisms during the Archaean period. We benefit from a large and unique collection of cores acquired in the framework of dedicated drilling programs performed by our group in key Archaean terranes in Australia (Pilbara Craton, 3.5 and 2.7 Gyr) and South Africa (Barberton, 3.4-3.2 Gyr).