Organic matter oxidation of the Tégulines Clay formation, (Paris Basin, France): Spatial Heterogeneities

Samples of Albian Tégulines Clay outcropping near Brienne-le-Château in the eastern part Paris Basin were subjected to a geochemical characterization organic matter (OM), combining OM bulk Rock-Eval analysis (RE), petrography and molecular analysis. In this study, objective was investigate oxidation natural critical zone developed early reduced marine clay formation. For that purpose, core samples from three boreholes crosscutting formation down Greensands selected. Several meters Brienne marls preserved atmosphere therefore high weathering AUB240 borehole, whereas weathered their upper AUB1010 AUB230 as result vicinity surface. The results showed Total Organic Carbon (TOC) contents all clays are very low, ranging between 0.3 0.7 wt%. RE data Tmax parameter indicate is immature. shows predominance gel-like amorphous by sulphurisation anoxic environments. show similar characteristics. at top contains large amounts oxidized lignocellulosic debris has Oxygen-Index values. first 10 m clays, bulk, revealed oxidative events (high OI contents). Below m, almost preserved. little functionalized seems be slightly reactive but not negligibly with inorganic fractions presence oxygen.