Diatom biostratigraphy of the middle- and high-latitude North Atlantic Ocean, Deep Sea Drilling Project Leg 94.

Abstract

Moderately well-preserved diatoms are present in lower Miocene to Quaternary sediment recovered during DSDP Leg 94, except for the upper middle Miocene to upper Miocene. The diatom species are characteristic of a warm-termperate assemblage similar to that described from the Rockall Plateau region of the N Atlantic Ocean. Diatom zonations for the upper Miocene to Quaternary and the diatom zonation from the Pacific Ocean is utilized in the lower and middle Miocene. Pliocene and Quaternary diatom datums are correlated directly to the paleomagnetic stratigraphy of Leg 94, and absolute ages are estimated for the 1st or last occurrence of species. Several biostratigraphic events are synchronous in the mid- to high-latitude N Atlantic Ocean but diachronous between the N Atlantic and N Pacific oceans. The occurrence of several species of diatom at several Leg 94 sites within the middle Quaternary of the N Atlantic Ocean suggests that an open communication may have existed between the N Atlantic Ocean and the Bering Sea.-from Author