A simple mixing explanation for late Pleistocene changes in the Pacific-South Atlantic benthic δ13C gradient

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doi: 10.5194/cp-6-305-2010
Author(s): Lisiecki, Lorraine E.
Author Affiliation(s): Primary:
University of California, Santa Barbara, Department of Earth Science, Santa Barbara, CA, United States
Volume Title: Climate of the Past
Source: Climate of the Past, 6(3), p.305-314. Publisher: Copernicus, Katlenburg-Lindau, International. ISSN: 1814-9324
Note: In English. Published in Climate of the Past Discussion: 23 December 2009, http://www.clim-past-discuss.net/5/2607/2009/cpd-5-2607-2009.html; accessed in Oct., 2010; abstract: doi:10.5194/cp-6-305-2010. 70 refs.; illus., incl. 1 table
Summary: The fact that the deep-ocean benthic δ13C minimum shifted from the North Pacific to the South Atlantic during the Last Glacial Maximum is often interpretted as evidence of a change in deep water circulation, such as the development of deep water ventilation in the North Pacific or a decrease in Southern Ocean overturning. This study re-evaluates the implications of changes in benthic δ13C gradients by comparing Pacific Deep Water (PDW) δ13C measurements with the values expected for the null hypothesis that PDW ventilation sources remained unchanged throughout the Late Pleistocene. The δ13C compositions of PDW, Northern Component Water (NCW) and Southern Component Water (SCW) are estimated from regional benthic δ13C stacks of 3-6 sites. Changes in PDW δ13C and PDW-SCW δ13C gradients over the past 800 kyr are found to be well described by a constant mixture of 60% NCW and 40% SCW plus a constant Pacific remineralization offset of -0.5 ppm. Thus, a change in PDW ventilation cannot be inferred solely on the basis of changes in the Pacific-South Atlantic benthic δ13C gradient.
Year of Publication: 2010
Research Program: DSDP Deep Sea Drilling Project
IPOD International Phase of Ocean Drilling
ODP Ocean Drilling Program
Key Words: 24 Surficial Geology, Quaternary Geology; Anomalinidae; Atlantic Ocean; Benthic environment; Benthic taxa; C-13; C-13/C-12; Cape Basin; Carbon; Cassidulinacea; Cenozoic; Cibicidoides; DSDP Site 552; Deep Sea Drilling Project; Deep-sea environment; Deep-water environment; East Pacific; Equatorial Pacific; Foraminifera; Glacial environment; Glaciomarine environment; IPOD; Interglacial environment; Invertebrata; Isotope ratios; Isotopes; Last glacial maximum; Leg 108; Leg 111; Leg 130; Leg 138; Leg 162; Leg 177; Leg 81; Marine environment; Microfossils; Mineralization; North Atlantic; North Pacific; North Pacific Deep Water; Northeast Pacific; Northwest Pacific; ODP Site 1089; ODP Site 1090; ODP Site 658; ODP Site 677; ODP Site 806; ODP Site 846; ODP Site 849; ODP Site 980; ODP Site 982; ODP Site 983; ODP Site 984; Ocean Drilling Program; Ontong Java Plateau; Pacific Deep Water; Pacific Ocean; Paleo-oceanography; Paleocirculation; Paleoclimatology; Pleistocene; Protista; Quaternary; Reykjanes Ridge; Rockall Bank; Rockall Plateau; Rotaliina; South Atlantic; South Pacific; Southeast Pacific; Southern Ocean; Stable isotopes; Upper Pleistocene; West Pacific
Record ID: 2011000639
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from Copernicus Gesellschaft, Katlenburg-Lindau, Germany

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