Geochemistry of Cocos plate pelagic- hemipelagic sediments in Hole 487, Deep Sea Drilling Project Leg 66 ( DSDP).

Abstract

The sedimentary sequence recovered from Hole 487 documents northeast seafloor spreading on the Cocos Plate. Analyses of 21 elements in 45 samples, taken at regular intervals up Hole 487, give a geochemical profile which shows metal enrichment in basal sediment similar to that observed in previously recovered basal sediment. The first sediment to be deposited on newly formed ocean crust is characteristically enriched in metals, particularly Fe and Mn. The metals precipitate from circulating hydrothermal-exhalative solutions which are an integral part of active ridge volcanism. The geochemistry of the basal metalliferous sediment from Hole 487 is discussed.-from Authors