LATE CENOZOIC OXYGEN AND CARBON ISOTOPIC HISTORY AND VOLCANIC ASH STRATIGRAPHY: DSDP SITE 284, SOUTH PACIFIC.

Abstract

In this study, the authors determined the oxygen and carbon isotopic compositions of three planktonic foraminiferal species, a benthonic foraminifer, and calcareous nannofossil assemblages, throughout DSDP (Deep Sea Drilling Project) site 284, which extends in age from Late Miocene to present-day. This investigation is the first to compare the stable isotopic composition of several different microfossil forms throughout such a Late Cenozoic sequence. The objectives of the study were: (1) to compare and contrast the oxygen isotopic records of several different microfossils; (2) to evaluate the isotopic data in terms of paleotemperature and paleoglacial history during the Late Cenozoic; (3) to provide additional data on carbon isotope variations in the Late Cenozoic; and (4) evaluate possible relations between the stratigraphic distribution of volcanic glass (ash) and the oxygen isotopic-paleoclimatic record.