Stable isotope record of planktonic foraminifera of sediment core TR163-19

Stable isotope data from eastern equatorial Pacific (EEP) core TR163-19 (2°15'N, 90°57'W, 2348 m) are presented for the surface-dwelling foraminifers Globigerinoides ruber and G. sacculifer and thermocline-dwelling Globorotalia menardii and Neogloboquadrina dutertrei. Using species-specifi...

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Bibliographic Details
Main Authors: Spero, Howard J, Mielke, Koreen M, Kalve, Erica M, Lea, David W, Pak, Dorothy K
Format: Dataset
Language:English
Published: PANGAEA 2003
Subjects:
AGE
DEPTH
sediment/rock
Globigerinoides ruber
δ13C
δ18O
Globigerinoides sacculifer
Globorotalia menardii
Isotope ratio mass spectrometry
Neogloboquadrina dutertrei
PC
Piston corer
TR163-19
Antarctic
Pacific
The Antarctic
Antarc*
Planktonic foraminifera
Online Access:https://doi.pangaea.de/10.1594/PANGAEA.841839
https://doi.org/10.1594/PANGAEA.841839
Description
Summary:Stable isotope data from eastern equatorial Pacific (EEP) core TR163-19 (2°15'N, 90°57'W, 2348 m) are presented for the surface-dwelling foraminifers Globigerinoides ruber and G. sacculifer and thermocline-dwelling Globorotalia menardii and Neogloboquadrina dutertrei. Using species-specific normalization factors derived from experimental and plankton tow data, we reconstruct a 360 kyr record of water column hydrography across the past three glacial cycles. We demonstrate that G. ruber maintains a mixed layer habitat throughout the entire record, while G. sacculifer records a mixture of thermocline and mixed layer conditions and G. menardii and N. dutertrei record thermocline properties. We conclude that G. sacculifer is not appropriate for paleoceanographic applications in regions with steep vertical hydrographic gradients. Results suggest that this region of the EEP had a thicker mixed layer and deeper d13CDIC boundary between the surface and equatorial undercurrent during the last two glacial periods. A shift in N. dutertrei and G. sacculifer geochemistry prior to ~185 kyr suggests water column structure and chemocline gradients changed, possibly due to a shift in the position of the undercurrent relative to this site. The timing and magnitude of glacial-interglacial d13C variations between species indicates that near-surface carbon chemistry is controlled by changes in productivity, atmospheric circulation, and advected intermediate water sources north of the Antarctic polar front. These results demonstrate that when properly calibrated for species differences, multispecies geochemical data sets can be invaluable for reconstructing water column structure and properties in the past.

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