November 28th 2019 – 13h : International seminar
Speaker
Jérémie AUBINEAU
UMR 7285 IC2MP, University of Poitiers
Topic
Paleoproterozoic bacterial mats from Gabon: Which messages?
Sediments dated to 2.1 billions years ago (Ga) in Gabon were deposited during a transition period for Earth history, following the first increase of atmospheric O2. This event (2.4 Ga – 2.1 Ga) has provided oceans with nutrients, boosting microbial life. Thanks to a study following multiple approaches and scales, a large diversity of bacterial mats were described in the Gabonese sediments. Macro- and microscopic observations as well as comparisons with modern analogs allowed documenting ten morphologies of bacterial mats. These microbial communities were mainly composed of cyanobacteria. Given that these bacteria can locally produce large quantities of O2, they could explain a priori the abundant presence of advanced life forms nearby the bacterial mats of Gabon. The mineralogy and isotopic geochemistry of bacterial mats allowed studying the influence of bacteria on their environments, and characterizing microbiological processes.
Jérémie Aubineau just finished his PhD thesis entitled « Multi-approach study of bacterial mats of the Paleoproterozoic (2.1 Ga, Gabon): Biogenicity, mineralogy, and biogeochemistry » at the laboratory IC2MP (University of Poitiers). This former student at PALEVOPRIM (paleontology master) has authored and co-authored several papers on the Precambrian deposits from Gabon, notably in Nature Communications.
Lieu
Room 410, build. B35 (3rd floor, north wing), University of Poitiers.
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