Resolving apparent conflicts between oceanographic and Antarctic climate records and evidence for a decrease in pCO2 during the Oligocene through early Miocene (34-16 Ma)

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doi: 10.1016/j.palaeo.2007.08.019
Author(s): Pekar, Stephen F.; Christie-Blick, Nicholas
Author Affiliation(s): Primary:
Queens College, School of Earth and Environmental Sciences, Flushing, NY, United States
Other:
British Antarctic Survey, United Kingdom
University of Leeds, United Kingdom
Lamont-Doherty Earth Observatory, United States
Volume Title: Antarctic cryosphere and Southern Ocean climate evolution (Cenozoic-Holocene)
Volume Author(s): Florindo, Fabio, editor; Nelson, Anna E.; Haywood, Alan M.
Source: Palaeogeography, Palaeoclimatology, Palaeoecology, 260(1-2), p.41-49; European Geophysical Union meeting, symposium on Antarctic cryosphere and Southern Ocean climate evolution (Cenozoic-Holocene), Vienna, Austria, April 2-7, 2006, edited by Fabio Florindo, Anna E. Nelson and Alan M. Haywood. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0031-0182 CODEN: PPPYAB
Note: In English. 59 refs.; chart, sketch map
Summary: An apparent mismatch between published oxygen isotopic data and other paleoclimate proxies for the span from 26-16 Ma is resolved by calibration against global sea-level estimates obtained from backstripping continental margin stratigraphy. Ice-volume estimates from calibrated oxygen isotope data compare favorably with stratigraphic and palynological data from Antarctica, and with estimates of atmospheric pCO2 throughout the Oligocene to early Miocene (34-16 Ma). Isotopic evidence for an East Antarctic Ice Sheet (EAIS) as much as 30% larger than its present-day volume at glacial maxima during that span is consistent with seismic reflection and stratigraphic evidence for an ice sheet covering much of the Antarctic continental shelf at the same glacial maxima. Palynological data suggest long-term cooling during the Oligocene, with cold near-tundra environments developing along the coast at glacial minima no later than the late Oligocene. A possible mechanism for this long-term cooling is a decrease in atmospheric pCO2 from the middle Eocene to Oligocene, reaching near pre-industrial levels by the latest Oligocene, and remaining at those depressed levels throughout the Miocene.
Year of Publication: 2008
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Antarctica; Calibration; Carbon dioxide; Cenozoic; Geochemistry; Glacial environment; Glaciomarine environment; Ice rafting; Ice volume; Isotope ratios; Isotopes; Leaves; Marine environment; Microfossils; Miocene; Neogene; O-18/O-16; Oligocene; Oxygen; Paleo-oceanography; Paleoatmosphere; Paleoclimatology; Paleoecology; Paleogene; Palynomorphs; Sea-level changes; Sediments; Southern Ocean; Stable isotopes; Temperate environment; Tertiary
Record ID: 2008093352
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands

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