Carbon isotope records from seven globally distributed marine sediment cores

Stable carbon isotope values of higher-plant leaf wax lipids were extracted, isolated, and measured from seven sediments cores. Sediment cores from DSDP/ODP Sites 94, 354, 511, 516, 608, 672, and 730 were taken from the North Atlantic, South Atlantic, and Indian Ocean Basins. New age models were developed using biostratigraphy and chemostratigraphic datams. Compound-specific isotope analyses of terrestrial leaf wax-derived odd-carbon number n-alkanes (n-C25 to n-C33) extracted from deep-sea drill cores were employed to evaluate relative contributions of C3 and C4 plant material delivered to marine sediments from the last 45 million years, with particular focus between 25-33 Ma. The purpose of this study was to assess the effects of CO2 decrease on the origin of the C4 pathway and the character of the Miocene C4 ecosystem development.