Oxygen and carbon isotopic composition in Eocene and Oligocene planktonic and benthic foraminifera from DSDP sediments ...

• Main Authors: Keigwin, Lloyd D, Corliss, Bruce H
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 1986
• Subjects: Drilling/drill rig; Leg2; Leg3; Leg9; Leg10; Leg12; Leg17; Leg22; Leg23; Leg26; Leg29; Leg31; Leg39; Leg40; Leg41; Leg48; Leg80; Leg90; Leg95; Glomar Challenger; Deep Sea Drilling Project DSDP; Planktonic foraminifera
• Online Access: https://dx.doi.org/10.1594/pangaea.719183; https://doi.pangaea.de/10.1594/PANGAEA.719183

Oxygen and carbon isotope ratios in Eocene and Oligocene planktonic and benthic foraminifera have been investigated from Atlantic, Indian, and Pacific Ocean locations. The major changes in Eocene-Oligocene benthic foraminiferal oxygen isotopes were enrichment of up to 1 per mil in 18O associated with the middle/late Eocene boundary and the Eocene/Oligocene boundary at locations which range from 1- to 4-km paleodepth. Although the synchronous Eocene-Oligocene 18O enrichment began in the latest Eocene, most of the change occurred in the earliest Oligocene. The earliest Oligocene enrichment in 18O is always larger in benthic foraminifera than in surface-dwelling planktonic foraminifera, a condition that indicates a combination of deep-water cooling and increased ice volume. Planktonic foraminiferal d18O does not increase across the middle/late Eocene boundary at our one site with the most complete record (Deep Sea Drilling Project Site 363, Walvis Ridge). This pattern suggests that benthic foraminiferal d18O ... : Supplement to: Keigwin, Lloyd D; Corliss, Bruce H (1986): Stable isotopes in late middle Eocene to Oligocene foraminifera. Geological Society of America Bulletin, 97(3), 335-345 ...