Paleoceanographic implications of a 17-m.y.-long record of high- latitude Miocene calcareous nannoplankton fluctuations

Abstract

A record based on counts of the relative abundance of the dominant calcareous nannofossil taxa Coccolithus pelagicus and Reticulofenestra spp. in sediments recovered from Ocean Drilling Program Hole 747A is established. This record virtually spans the entire Miocene. Based on the variations, five stratigraphic units characterized by high abundance in C. pelagicus are delineated. The five defined units are tentatively correlated to well-known global isotopic events. Time-series analysis indicates the presence of the three main periodic components of the eccentricity of the Earth's orbit. A 200-k.y. cycle is also present. -from Authors