Astronomic timescale for the Pliocene Atlantic δ18O and dust flux records of Ocean Drilling Program site 659.

Tiedemann, Ralf, Sarntheim, Michael and Shackleton, Nicolas J. (1994) Astronomic timescale for the Pliocene Atlantic δ18O and dust flux records of Ocean Drilling Program site 659. Paleoceanography, 9 (4). pp. 619-638. DOI 10.1029/94PA00208.

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Abstract

High-resolution benthic oxygen isotope and dust flux records from Ocean Drilling Program site 659 have been analyzed to extend the astronomically calibrated isotope timescale for the Atlantic from 2.85 Ma back to 5 Ma. Spectral analysis of the δ18O record indicates that the 41-kyr period of Earth's orbital obliquity dominates the Pliocene record. This is shown to be true regardless of fundamental changes in the Earth's climate during the Pliocene. However, the cycles of Sahelian aridity fluctuations indicate a shift in spectral character near 3 Ma. From the early Pliocene to 3 Ma, the periodicities were dominantly precessional (19 and 23 kyr) and remained strong until 1.5 Ma. Subsequent to 3 Ma, the variance at the obliquity period (41 kyr) increased. The timescale tuned to precession suggests that the Pliocene was longer than previously estimated by more than 0.5 m.y.

Document Type: Article
Keywords: Pliocene; Atlantic; δ18O; Dust flux; ODP site 659
Research affiliation: OceanRep > GEOMAR > FB1 Ocean Circulation and Climate Dynamics > FB1-P-OZ Paleo-Oceanography
Kiel University
Refereed: Yes
Open Access Journal?: No
Publisher: AGU (American Geophysical Union)
Projects: ODP
Date Deposited: 06 Apr 2016 12:31
Last Modified: 23 Sep 2019 19:22
URI: https://oceanrep.geomar.de/id/eprint/31981

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