Pliocene switch in orbital-scale carbon cycle/climate dynamics

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doi: 10.1002/2014PA002651
Author(s): Turner, Sandra Kirtland
Author Affiliation(s): Primary:
University of Bristol, School of Geographical Sciences, Bristol, United Kingdom
Volume Title: Paleoceanography
Source: Paleoceanography, 29(12), p.1256-1266. Publisher: American Geophysical Union, Washington, DC, United States. ISSN: 0883-8305 CODEN: POCGEP
Note: In English. 70 refs.; illus., incl. 1 table
Summary: The high-frequency (periods of ∼105 years) relationship between carbon and oxygen isotopes in benthic foraminifera-the two proxies most extensively used to reconstruct past changes in Earth's carbon cycle and climate-shows two distinct patterns across the Cenozoic. The first, "glacial-style," pattern associates negative excursions in δ13C with positive excursions in δ18O indicative of relatively cold temperatures and greater ice volume. The second, "hyperthermal-style," pattern associates negative excursions in δ13C with negative excursions in δ18O indicative of warming. Here I assess the coherence and phasing of these high-frequency, orbital-scale cycles (in particular, the ∼100 kyr eccentricity period) in δ13C and δ18O from multiple high-resolution benthic foraminiferal records spanning the last ∼65 million years of Earth history in order to identify which of these patterns is most persistent across the Cenozoic and when the switch between these patterns occurred. I find that the glacial-style δ13C-δ18O pattern is a feature restricted to the Plio-Pleistocene, suggesting a fundamental change in the interplay between the carbon cycle and climate associated with the onset of Northern Hemisphere glaciation. This relative stability of the high-frequency relationship between δ13C and δ18O across most of the Cenozoic persists despite significant secular changes in climate and may suggest a dichotomous response of terrestrial carbon cycle dynamics to orbital forcing with a switch occurring in the last ∼5 Myr. Abstract Copyright (2014), . American Geophysical Union. All Rights Reserved.
Year of Publication: 2014
Research Program: ODP Ocean Drilling Program
Key Words: 02 Geochemistry; 12 Stratigraphy, Historical Geology and Paleoecology; Atlantic Ocean; Benthic taxa; C-13/C-12; Carbon; Carbon cycle; Ceara Rise; Cenozoic; Climate forcing; Demerara Rise; East Pacific; Equatorial Atlantic; Equatorial Pacific; Foraminifera; Geochemical cycle; Indian Ocean; Invertebrata; Isotope ratios; Isotopes; Kerguelen Plateau; Leg 120; Leg 138; Leg 154; Leg 162; Leg 184; Leg 198; Leg 199; Leg 202; Leg 207; Leg 208; Microfossils; Nazca Ridge; Neogene; North Atlantic; North Pacific; Northeast Pacific; Northwest Atlantic; Northwest Pacific; O-18/O-16; ODP Site 1146; ODP Site 1209; ODP Site 1218; ODP Site 1237; ODP Site 1258; ODP Site 1262; ODP Site 748; ODP Site 846; ODP Site 849; ODP Site 926; ODP Site 982; Ocean Drilling Program; Orbital forcing; Oxygen; Pacific Ocean; Paleoclimatology; Pliocene; Protista; Rockall Bank; Shatsky Rise; South Atlantic; South China Sea; South Pacific; Southeast Pacific; Stable isotopes; Tertiary; Walvis Ridge; Wavelets; West Atlantic; West Pacific
Coordinates: S582627 S582627 E0785854 E0785853
N001058 N001100 W1103110 W1103111
S030549 S030541 W0904904 W0904906
N573100 N573100 W0155200 W0155200
Record ID: 2015016322
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from John Wiley & Sons, Chichester, United Kingdom