BAYON , Germain

Chemical weathering of silicate rocks on continents acts as a major sink for atmospheric carbon dioxide and has played an important role in the evolution of the Earth's climate. However, the magnitude and the nature of the links between weathering and climate are still under debate. In particular, the timescale over which chemical weathering...

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In this study, the accuracy and the precision corresponding to Li isotopic measurements of low level samples such as marine and coastal carbonates are estimated. To this end, a total of fifty‐four analyses of a Li‐pure reference material (Li7‐N) at concentrations ranging from 1 to 6 ng ml−1 were first performed. The average δ7Li values obtained...

Human-induced environmental disturbances during the Holocene have provided support for the Early Anthropogenic Hypothesis (EAH), which proposes that with the advent of agro-pastoralism and associated deforestation, humans have modified CO2 and CH4 concentrations into the atmosphere. However, only limited evidence exists for human driven...

Human-induced environmental disturbances during the Holocene have provided support for the Early Anthropogenic Hypothesis (EAH), which proposes that with the advent of agro-pastoralism and associated deforestation, humans have modified CO2 and CH4 concentrations into the atmosphere. However, only limited evidence exists for human driven...

During the Pleistocene, tropical Africa was the site of significant hydrologic changes related to variations in the intensity of the African monsoon. The socalled African Humid Period (AHP) has been known for some time, the AHP is being revisited today with the aid of innovative geochemical and organic tools such as lithium isotope and...

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Marine sediments at ocean margins vent substantial amounts of methane. Microbial oxidation of the methane released can trigger the precipitation of carbonate within sediments and support a broad diversity of seafloor ecosystems. The factors controlling microbial activity and carbonate precipitation associated with the seepage of submarine fluid...

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Marine sediments at ocean margins vent substantial amounts of methane. Microbial oxidation of the methane released can trigger the precipitation of carbonate within sediments and support a broad diversity of seafloor ecosystems. The factors controlling microbial activity and carbonate precipitation associated with the seepage of submarine fluid...

This paper reports the first "in situ" seafloor observations of fluid escape structures in a fault-controlled caldera-type depression of about 8 km diameter, named the Menes caldera, in the Eastern Mediterranean sea off Egypt (western province of the Nile Deep Sea Fan). A detailed analysis of seven Nautile dives, performed during the Nautinil...

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We report on a multidisciplinary study of cold seeps explored in the Central Nile deep-sea fan of the Egyptian margin. Our approach combines in situ seafloor observation, geophysics, sedimentological data, measurement of bottom-water methane anomalies, pore-water and sediment geochemistry, and 230Th/U dating of authigenic carbonates. Two areas...

The Demerara plateau, located offshore French Guiana and Suriname, is part of a passive transform continental margin particularly prone to develop slope instabilities, probably in relation to the presence of a free distal border along its steep continental slope. Slope failure occurred at different periods (Cretaceous to Neogene) and shows an...