Skip to main content
U.S. flag

An official website of the United States government

Miocene benthic foraminiferal isotope records: A synthesis

January 1, 1981

18O 16O and 13C 12C ratios of Miocene benthic foraminifera from a number of Atlantic, Pacific and Indian Ocean DSDP sites (71, 77B, 206, 208, 238, 279, 289, 296, 329, 357 and 366A) have been compiled. These provide a rather detailed history of Miocene deep water especially in the Pacific Ocean. Bottom-water temperatures rose during the early Miocene and then declined rapidly during the middle Miocene. This decline was accompanied by an increase in Antarctic glaciation. Late Miocene bottom temperatures and Antarctic ice volumes are inferred to be similar to today's, but exhibited some fluctuation. The early Miocene ocean was less thermally stratified at intermediate and abyssal depths while the late Miocene deep ocean had a thermal structure generally similar to the modern ocean. Foraminiferal carbon isotope ratios at most of the sites varied quasi-sympathetically throughout the Miocene. These variations must reflect comparable variations in the mean 13C 12C of marine HCO3-. However, the causes of such variations are not yet clear. ?? 1981.

Publication Year 1981
Title Miocene benthic foraminiferal isotope records: A synthesis
Authors S.M. Savin, R.G. Douglas, G. Keller, J.S. Killingley, L. Shaughnessy, M.A. Sommer, E. Vincent, F. Woodruff
Publication Type Article
Publication Subtype Journal Article
Series Title Marine Micropaleontology
Index ID 70011986
Record Source USGS Publications Warehouse