Petrographic, cathodoluminescent, and compositional characters of organic dolomites from ODP Leg 175 holes

The main objective of Leg 175 was to reconstruct the Late Neogene paleoceanographic history of the Benguela Current and associated upwelling regimes along the southwest African margin between 5° and 32°S. This area is one of the great upwelling regions of the world and plays an important role in the global ocean-carbon cycle. It is characterized by organic-rich sediments that contain a high-resolution record of productivity history that is closely linked to changes in regional dynamics of circulation, mixing, and upwelling (Wefer et al., 1998, doi:10.2973/odp.proc.ir.175.1998). The Benguela Current region also provides an excellent setting to investigate the early diagenetic processes governing the formation of authigenic dolomite. Although unexpected, the discovery of widespread and pervasive dolomite horizons along the southwest African margin was one of the principal findings of Leg 175. […]