Neogene Benthic Foraminifera of the Hatton-Rockall Basin

Abstract

A quantitative analysis is presented of benthic foraminifera from 25 samples of the Miocene and Pliocene section of DSDP Site 116 (eastern margin of the Hatton-Rockall Basin in the northeast Atlantic). Taxonomic turnover was gradual; however, abundance changes (dominance) were dramatic. During the early Middle Miocene, a major abundance change occurred to an assemblage dominated by modern taxa. This change can be associated with major stable isotopic changes documented at this time, and suggests a benthic foraminiferal response to a major reorganization of oceanic circulation. The causes of subsequent assemblage dominance fluctuations are more ambiguous; an increase in the Uvigerina fauna in the Early Pliocene may be associated with more negative .delta.13C values and a decreased contrast in .delta.13C between the Atlantic and Pacific, the latter possibly indicative of reduced circulation in this part of the Atlantic.