ENVIRONMENTAL AND ANTHROPIC CONTROLS ON SEDIMENTS AND BIOMARKER DEPOSITION IN A DECANTATION TANK (ORLEANS, FRANCE)
Résumé
Introduction
Human activities are being registered by an unprecedented variety and concentration of markers in the sedimentary record. This is the founding concept of the Anthropocene for which a lower boundary was set at 1945 (Zalasiewicz et al., 2016) and a Global Boundary Stratotype Section and Point (GSSP) is currently under examination (Waters et al., 2018). Within the Golden Spike project (BIOHEFECT-EC2CO, CNRS-INSU) we propose that sedimentary archives deposited in sewer networks of urban areas constitute targets for Anthropocene GSSP because they are susceptible of recording a high diversity of concentrated matters, elements, biomarkers and isotopes of human origin through time. Before exploring such sediments, we investigate their potential as archives, i.e. the factors affecting their deposition processes, the availability of pertinent tracers and the controls on their archivability.