Quaternary isotope stratigraphy of DSDP Hole 90-593 from the Challenegr Plateau, South Tasman Sea

A moderate-resolution isotope stratigraphy (with an average of one sample per 17,500 yr.) derived from the benthic foraminifer Uvigerina (or Cibicides), the planktonic foraminifer Globigerina bulloides, and calcareous nannofossil concentrates is presented for the entire Quaternary (and latest Plioce...

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Bibliographic Details
Main Authors: Nelson, Campbell S, Hendy, Chris H, Dudley, Walter C
Format: Dataset
Language:English
Published: PANGAEA 1986
Subjects:
90-593
Deep Sea Drilling Project
DRILL
Drilling/drill rig
DSDP
Glomar Challenger
Leg90
South Pacific/Tasman Sea/PLATEAU
Antarctic
New Zealand
Pacific
Antarc*
Online Access:https://doi.pangaea.de/10.1594/PANGAEA.683884
https://doi.org/10.1594/PANGAEA.683884
Description
Summary:A moderate-resolution isotope stratigraphy (with an average of one sample per 17,500 yr.) derived from the benthic foraminifer Uvigerina (or Cibicides), the planktonic foraminifer Globigerina bulloides, and calcareous nannofossil concentrates is presented for the entire Quaternary (and latest Pliocene) section of mid-upper bathyal calcareous oozes from DSDP Site 593, western Challenger Plateau, south Tasman Sea. Superimposed on a trend of gradually increasing average delta18O values through the Pleistocene, reflecting the progressive buildup of polar ice sheets, is a record of highfrequency but generally low amplitude (0.5-1‰) isotope fluctuations in the early Quaternary (1.9-1.0 m.y.), followed by a greatly increased intensity (1.5-2.0 ‰) of glacial-interglacial fluctuations during the late Quaternary (< 1.0 m.y.). The standard late Quaternary isotope stages 1 to 24 are mainly resolvable. Significant excursions in both delta18O and delta13C values at various times during the Quaternary are suggested to be due to periodic, fundamental changes in ocean circulation properties over the plateau. For example, intensified upwelling of Antarctic Intermediate Waters during several glacial periods is indicated by the convergence of benthic and planktonic foraminiferal delta18O data, and productivity variations may account for certain delta13C spikes in the record. With increasingly higher resolution analysis this core will provide a useful Quaternary isotope reference section for southern temperate waters in the southwest Pacific, centered on New Zealand.

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