Chemostratigraphy - A tool for understanding transport processes at the continental margin off West-Africa

Abstract

Continental margins as complex interfaces between continents and ocean basins, display a variety of gravity-driven depositional environments. Understanding the interaction of external and internal control mechanisms of sediment transport processes in these environments is important in order to reconstruct their sedimentary history. This study focuses on the geochemical imprints left in the sediment material and its corresponding fluid phase by gravity-driven sediment events and transport processes. High resolution geochemical investigations of the sediments and their fluids provide a detailed characterization of the material allowing conclusions on possible changes in the depositional environment and the related processes. The chemical composition of pore water may document recent changes in the sedimentation pattern caused by slide events. Modeling fluid concentration profiles helps estimating the event age. Geochemical fingerprinting of turbidites in a chemostratigraphic approach provides a more precise characterization of sediments and corresponding sources, and help facilitate reconstruction of transport pathways.