The deposition of reef-derived sediment upon a bathyal slope: The deep off-reef environment, north of Discovery Bay, Jamaica

Abstract

The steep submarine slope north of Jamaica was formed as a normal fault scarp during the early rifting of the Cayman Trough. It is overgrown at the top by flourishing reefs, and below these a series of irregular valleys have been cut into the rocks of the slope and run downslope to at least 2,500 m. Cores from these valleys contain thin layers of reef-derived sands interbedded with pelagic muds of Quaternary age. Cores from topographically high areas recovered only pelagic muds. It is shown that bottom currents and turbidity currents are both unlikely to have been the agencies responsible for the deposition of the reef-derived sands, but that they were probably emplaced by either free avalanching or by sand flow.