Benthic foraminiferal assemblages of middle to late Pliocene sediments in the North Atlantic Ocean, supplement to: Ishman, Scott E (1996): A benthic foraminiferal record of middle to late Pliocene (3.15-2.85 Ma) deep water change in the North Atlantic. Marine Micropaleontology, 27(1-4), 165-180

Records of benthic foraminifera from North Atlantic DSDP Site 607 and Hole 610A indicate changes in deep water conditions through the middle to late Pliocene (3.15 to 2.85 Ma). Quantitative analyses of modem associations in the North Atlantic indicate that seven species, Fontbotia wuellerstorfi, Cib...

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Bibliographic Details
Main Author: Ishman, Scott E
Format: Article in Journal/Newspaper
Language:English
Published: PANGAEA - Data Publisher for Earth & Environmental Science 1996
Subjects:
Drilling/drill rig
Leg94
Glomar Challenger
Deep Sea Drilling Project DSDP
Southern Ocean
NADW
North Atlantic Deep Water
North Atlantic
Online Access:https://dx.doi.org/10.1594/pangaea.682260
https://doi.pangaea.de/10.1594/PANGAEA.682260
Description
Summary:Records of benthic foraminifera from North Atlantic DSDP Site 607 and Hole 610A indicate changes in deep water conditions through the middle to late Pliocene (3.15 to 2.85 Ma). Quantitative analyses of modem associations in the North Atlantic indicate that seven species, Fontbotia wuellerstorfi, Cibicidoides kullenbergi, Uvigerina peregrina, Nuttallides umboniferus, Melonis pompilioides, Globocassidulina subglobosa and Epistominella exigua are useful for paleoenvironmental interpretation. The western North Atlantic basin (Site 607) was occupied by North Atlantic Deep Water (NADW) until c. 2.88 Ma. At that time, N. umboniferus increased, indicating an influx of Southern Ocean Water (SOW). The eastern North Atlantic basin (Hole 610A) was occupied by a relatively warm water mass, possibly Northeastern Atlantic Deep Water (NEADW), through c. 2.94 Ma when SOW more strongly influenced the site. These interpretations are consistent with benthic delta18O and delta13C records from 607 and 610A (Raymo et al., 1992). The results presented in this paper suggest that the North Atlantic was strongly influenced by northern component deep water circulation until 2.90-2.95 Ma. After that there was a transition toward a glacially driven North Atlantic circulation more strongly influenced by SOW associated with the onset of Northern Hemisphere glaciation. The circulation change follows the last significant SST and atmospheric warming prior to c. 2.6 Ma.

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