A5030190589- Paleontology and Stratigraphy of Fossils
- Geology and Paleoclimatology Research
- Hydrocarbon exploration and reservoir analysis
- Methane Hydrates and Related Phenomena
- Geological and Geochemical Analysis
- Geochemistry and Elemental Analysis
- Isotope Analysis in Ecology
- Geological and Geophysical Studies
- Pleistocene-Era Hominins and Archaeology
- Geochemistry and Geologic Mapping
- Planetary Science and Exploration
- Plant Diversity and Evolution
- Mass Spectrometry Techniques and Applications
- Marine and environmental studies
- Astro and Planetary Science
- Geological formations and processes
- Microbial Community Ecology and Physiology
- Plant and Fungal Species Descriptions
- Ion-surface interactions and analysis
- Geomagnetism and Paleomagnetism Studies
- Polar Research and Ecology
- Geological Studies and Exploration
- Radioactive element chemistry and processing
- Molecular Biology Techniques and Applications
- Diatoms and Algae Research
Institut Universitaire de France
2021-2024
Centre National de la Recherche Scientifique
2013-2024
Laboratoire d’Océanologie et de Géosciences
2015-2024
Université de Lille
2013-2024
Institut de Recherche pour le Développement
2023-2024
Université du littoral côte d'opale
2021-2023
Laboratoire de Physique des Lasers, Atomes et Molécules
2021
University of Liège
2009-2018
NASA Astrobiology Institute
2012-2016
University of Wisconsin–Madison
2015-2016
Microscopic sulfides with low 34S/32S ratios in marine sulfate deposits from the 3490-million-year old Dresser Formation, Australia, have been interpreted as evidence for presence of early sulfate-reducing organisms on Earth. We show that these microscopic a mass-independently fractionated sulfur isotopic anomaly (Delta33S) differs their host (barite). These could not produced by microbes, nor abiologic processes involve reduction sulfate. Instead, we interpret combined negative delta34S and...
The Archean era (4 to 2.5 billion years ago, Ga) yielded rocks that include the oldest conclusive traces of life as well many controversial occurrences. Carbonaceous matter is found in old 3.95 Ga, but (graphitic) forms may be abiogenic. Due metamorphism altered molecular composition all organic matter, non-biological carbonaceous compounds such those could have formed seafloor hydrothermal systems are difficult rule out. Benthic microbial mats 3.47 Ga supported by record laminae...
The Paleoproterozoic (2.5–1.6 Ga) Era is a decisive time in Earth and life history. paleobiological record (microfossils, stromatolites, biomarkers isotopes) illustrates the biosphere evolution during of transitional oceanic atmosphere chemistries. Benthic microfossil assemblages are recorded variety oxygenated, sulfidic, ferruginous environments representative spatial heterogeneities temporal variations characteristic this Era. include iron-metabolizing and/or iron-tolerant prokaryotes,...
Morphologically diverse structures that may constitute organic microfossils are reported from three remote and widely separated localities assigned to the ca. 3400 Ma Strelley Pool Formation in Pilbara Craton, Western Australia. These include Panorama, Warralong, Goldsworthy greenstone belts. From Panorama belt, large (>40 μm) lenticular spindle-like structures, spheroidal mat-forming thread-like found. Similar assemblages of carbonaceous have been identified Warralong belts, though these...
Abstract Glacial episodes have been linked to Ordovician–Silurian extinction events, but cooling itself may not be solely responsible for these extinctions. Teratological (malformed) assemblages of fossil plankton that correlate precisely with the events can help identify alternate drivers extinction. Here we show metal poisoning caused aberrant morphologies during a late Silurian (Pridoli) event. Malformations coincide dramatic increase metals (Fe, Mo, Pb, Mn and As) in fossils their host...
Abstract The Strelley Pool Formation ( SPF ) is widely distributed in the East Pilbara Terrane EPT of Craton, Western Australia, and represents a Paleoarchean shallow‐water to subaerial environment. It was deposited ~3.4 billion years ago displays well‐documented carbonate stromatolites. Diverse putative microfossils microfossils) were recently reported from several localities Strelley, Panorama, Warralong, Goldsworthy greenstone belts. Thus, provides unparalleled opportunities gain insights...
Abstract Problematic microfossils dominate the palaeontological record between Great Oxidation Event 2.4 billion years ago (Ga) and last Palaeoproterozoic iron formations, deposited 500–600 million later. These fossils are often associated with iron-rich sedimentary rocks, but their affinities, metabolism, and, hence, contributions to Earth surface oxidation Fe deposition remain unknown. Here we show that specific microfossil populations of 1.88 Ga Gunflint Iron Formation contain Fe-silicate...
Abstract An approach to coordinated, spatially resolved, in situ carbon isotope analysis of organic matter and carbonate minerals, sulfur three‐ four‐isotope pyrite with an unprecedented combination spatial resolution, precision, accuracy is described. Organic from eleven rock samples Neoarchean drill core express nearly the entire range δ 13 C, 34 S, Δ 33 36 S known geologic record, commonly correlation morphology, mineralogy, elemental composition. A new analytical (including a set...
Abstract Lacustrine microbial mats in A ntarctic ice‐free oases are considered modern analogues of early ecosystems as their primary production is generally dominated by cyanobacteria, the heterotrophic food chain typically truncated due to extreme environmental conditions, and they geographically isolated. To better understand fossilization mineralization processes this context, we studied microstructure chemistry organo‐mineral associations a suite sediments 50–4530 cal. years old from...
Land plants comprise the bryophytes and polysporangiophytes. All extant polysporangiophytes are vascular (tracheophytes), but to date, some basalmost (also called protracheophytes) considered non-vascular. Protracheophytes include Horneophytopsida Aglaophyton/Teruelia. They most generally phylogenetically intermediate between therefore essential elucidate origins of current floras. Here, we propose an alternative evolutionary framework for earliest tracheophytes. The supporting evidence...
Abstract The study of the earliest traces life on Earth can be complicated by abiotically formed biomorphs. We report here finding clustered micrometer‐sized filaments iron‐ and calcium‐rich garnets associated with carbonaceous matter in an agate amygdale from a 2.7‐billion‐year‐old basalt Maddina Formation, Western Australia. distribution mineral phases composing were analyzed using combination confocal laser scanning microscopy, laser‐Raman micro‐spectroscopy, focused ion beam sectioning...