Late Cenozoic stable isotope record of benthic and planktonic foraminifera from the Pacific Ocean ...

• Main Author: Keigwin, Lloyd D
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 1979
• Subjects: Drilling/drill rig; Leg16; Leg32; Glomar Challenger; Deep Sea Drilling Project DSDP; Antarc*; Antarctic; Ice cap; Ice Sheet; Planktonic foraminifera
• Online Access: https://dx.doi.org/10.1594/pangaea.710854; https://doi.pangaea.de/10.1594/PANGAEA.710854

Stable isotopic analyses of Middle Miocene to Quaternary foraminiferal calcite from east equatorial and central north Pacific DSDP cores have provided much new informatlon on the paleoceanography of the Pacific Neogene The history of delta18O change in planktonic foraminifera reflects the changing Isotopic composition and temperature of seawater at the time of test formation. Changes in the isotopic composition of benthonic foraminifera largely reflect changes m the volume of continental ice. Isotopic data from these cores indicates the following sequence of events related to continental glaciation(1) A permanent Antarctic ice sheet developed late in the Middle Miocene (about 13 to 11.5 m.y. ago)(2) The Late Miocene (about 11.5 to 5 m.y. ago) is marked by significant variation in delta18O of about 0.5‰ throughout, indicating instability of Antarctic ice cap size or bottom-water temperatures(3) The early Pliocene (5 to about 3 m.y. ago) was a time of relative stability in ice volume and bottom-water ... : Supplement to: Keigwin, Lloyd D (1979): Late Cenozoic stable isotope stratigraphy and paleoceanography of DSDP sites from the east equatorial and central north Pacific Ocean. Earth and Planetary Science Letters, 45(2), 361-382 ...