Timing and paleoceanography of oceanic dysoxia/anoxia in the late Barremian to early Aptian (early Cretaceous)

Normal marine deposition in the early Aptian was interrupted by an episode of ocean-wide dysoxia/anoxia. This event is recorded by the occurrence of organic carbon-rich sediments in land sections from Europe and DSDP/ODP sites in the North and South Atlantic, Indian and Pacific Ocean Basins. To elucidate the origin, and spatial and temporal relationships of these carbonaceous sediments, an integrated biostratigraphic, lithostratigraphic and geochemical investigation has been conducted of fourteen sections from a range of geographic and oceanographic settings. Based on the resulting high-resolution, integrated foraminiferal and nannofossil biostratigraphy, it appears that most locations were characterized by a relatively brief interval of peak dysoxia/anoxia in the midst of a longer interval of intermittent oxygen deficiency which began in the late Barremian. -from Authors