Late Mesozoic and Cenozoic Sedimentation Along Ocean Island Margins: Analog to Continental Margins

The depositional environments along Pacific island margins have been used as analogs to elucidate depositional processes along continental margins, controlled by their tectonic and volcanic, climatic, hydrographic and biologic evolution. Intervals of low eustatic sea levels led to be displacement of shallow water sediments (with their contents of neritic fossils) into the adjacent deep-sea basins. Eight erosional pulses when neritic fossils were displaced into the deep-sea, can be discerned in the central Pacific during the past 130 MY. Velocities of oceanic bottom water currents which affected island margin sedimentation, were slow in the Cretaceous Pacific, but they eroded sediments in intermediate water depths since Maastrichtian time. Mechanical erosion seems to have generated most hiatuses. The temporal distribution of the abundance of displaced pelagic fossils reveals the development of vigorous current regimes during the past 42-44 my within the meso- and bathypelagic parts of the Pacific water column. This is considered important for an understanding of the distribution and development of pelagic oxygen-deficient depositional environments