Extinction of deep-sea Foraminifera as a result of Pliocene-Pleistocene deep-sea circulation changes in the South China Sea (ODP Sites 1143 and 1146)

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doi: 10.1016/j.quascirev.2006.10.011
Author(s): Kawagata, Shungo; Hayward, Bruce W.; Kuhnt, Wolfgang
Author Affiliation(s): Primary:
Geomarine Research, Auckland, New Zealand
Christian-Albrechts-Universität, Federal Republic of Germany
Volume Title: Quaternary Science Reviews
Source: Quaternary Science Reviews, 26(5-6), p.808-827. Publisher: Elsevier, International. ISSN: 0277-3791
Note: In English. Includes appendix. 66 refs.; illus., incl. 3 tables, sketch map
Summary: During the Late Pliocene-Middle Pleistocene, 56 species and 15 genera of elongate, cylindrical benthic foraminifera disappeared from the deep sea in the South China Sea (ODP Sites 1143 and 1146) as part of the last global extinction in the deep sea. This extinction group (Ext. Gp) exhibited a pulsed decline in abundance and species richness mostly during glacials, and often associated with periods of expansion of polar ice that resulted from increased cooling of the Earth's climate since ∼2.5 Ma, particularly during the Mid-Pleistocene Climate Transition (MPT, 1.2-0.6 Ma). We infer that the Ext. Gp decline in abundance and disappearance was a result of the increased glacial cooling and consequent increased ventilation of the deep-sea water masses. The detailed record of withdrawal of the Ext. Gp differs between the two sites, with far more disappearances occurring prior to the MPT in the deeper Site 1143 (2772 m) than in the shallower Site 1146 (2092 m). The Late Pliocene and Early Pleistocene declines in deeper parts of the South China Sea (Site 1143) may have resulted from enhanced glacial production of deep, southern-sourced water passing over the sill into the basin from the North-west Pacific. During the MPT however, the Ext. Gp declines and disappearances were of similar timing and magnitude in both sites, implying that both were influenced by the same deep-water mass during glacials at this time. This could have been North Pacific Deep Water, which many workers infer was formed in the northern Pacific during the last glacial, and may have begun forming during MPT glacials, in association with the progressively enhanced cooling of the Northern Hemisphere. Abstract Copyright (2007) Elsevier, B.V.
Year of Publication: 2007
Research Program: ODP Ocean Drilling Program
Key Words: 24 Surficial Geology, Quaternary Geology; Anaerobic environment; Assemblages; Benthic environment; Cenozoic; Deep-sea environment; Deep-water environment; Extinction; Foraminifera; Glacial environment; Invertebrata; Leg 184; Lower Pleistocene; Marine environment; Marine sediments; Microfossils; Neogene; North Pacific; Northwest Pacific; ODP Site 1143; ODP Site 1146; Ocean Drilling Program; Ocean circulation; Pacific Ocean; Paleo-oceanography; Paleocurrents; Pleistocene; Pliocene; Protista; Quaternary; Sediments; South China Sea; Tertiary; Upper Pliocene; West Pacific
Coordinates: N092143 N092143 E1131707 E1131707
N192724 N192724 E1161622 E1161622
Record ID: 2009078350
Copyright Information: GeoRef, Copyright 2017 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands