Constraints on ocean circulation at the Paleocene-Eocene Thermal Maximum from neodymium isotopes

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doi: 10.5194/cp-12-837-2016
Author(s): Abbott, April N.; Haley, Brian A.; Tripati, Aradhna K.; Frank, Martin
Author Affiliation(s): Primary:
Oregon State University, College of Earth, Ocean, and Atmospheric Sciences, Corvallis, OR, United States
Other:
University of California at Los Angeles, United States
GEOMAR-Helmholtz Centre for Ocean Research, Germany
Volume Title: Climate of the Past
Source: Climate of the Past, 12(4), p.837-847. Publisher: Copernicus, Katlenburg-Lindau, International. ISSN: 1814-9324
Note: In English. 66 refs.; illus., incl. 4 tables
Summary: Global warming during the Paleocene-Eocene Thermal Maximum (PETM) ∼ 55 million years ago (Ma) coincided with a massive release of carbon to the ocean-atmosphere system, as indicated by carbon isotopic data. Previous studies have argued for a role of changing ocean circulation, possibly as a trigger or response to climatic changes. We use neodymium (Nd) isotopic data to reconstruct short high-resolution records of deep-water circulation across the PETM. These records are derived by reductively leaching sediments from seven globally distributed sites to reconstruct past deep-ocean circulation across the PETM. The Nd data for the leachates are interpreted to be consistent with previous studies that have used fish teeth Nd isotopes and benthic foraminiferal δ13C to constrain regions of convection. There is some evidence from combining Nd isotope and δ13C records that the three major ocean basins may not have had substantial exchanges of deep waters. If the isotopic data are interpreted within this framework, then the observed pattern may be explained if the strength of overturning in each basin varied distinctly over the PETM, resulting in differences in deep-water aging gradients between basins. Results are consistent with published interpretations from proxy data and model simulations that suggest modulation of overturning circulation had an important role for initiation and recovery of the ocean-atmosphere system associated with the PETM.
Year of Publication: 2016
Research Program: DSDP Deep Sea Drilling Project
IPOD International Phase of Ocean Drilling
ODP Ocean Drilling Program
Key Words: 02 Geochemistry; 12 Stratigraphy, Historical Geology and Paleoecology; Atlantic Ocean; Blake Nose; Blake Plateau; Bottom water; C-13/C-12; Carbon; Cenozoic; Cores; DSDP Site 213; DSDP Site 401; DSDP Site 527; Deep Sea Drilling Project; Deep-sea environment; East Pacific; Equatorial Pacific; ICP mass spectra; IPOD; Indian Ocean; Isotope ratios; Isotopes; Leg 113; Leg 171B; Leg 198; Leg 199; Leg 22; Leg 48; Leg 74; Marine environment; Marine sediments; Mass spectra; Maud Rise; Metals; Nd-144/Nd-143; Nd-146/Nd-144; Neodymium; North Atlantic; North Pacific; Northeast Pacific; Northwest Pacific; ODP Site 1051; ODP Site 1209; ODP Site 1220; ODP Site 690; Ocean Drilling Program; Ocean circulation; Pacific Ocean; Paleo-oceanography; Paleocene-Eocene Thermal Maximum; Paleocirculation; Paleogene; Rare earths; Sample preparation; Sediments; Shatsky Rise; Solution; South Atlantic; Southern Ocean; Spatial variations; Spectra; Stable isotopes; Tertiary; Theoretical models; Thermal ionization mass spectra; Thermohaline circulation; Walvis Ridge; Weddell Sea; West Pacific
Coordinates: S101243 S101242 E0935347 E0935346
S301000 S280000 E0031000 E0014500
N295500 N300900 W0760600 W0763800
S704954 S614837 E0030559 W0432706
Record ID: 2017017643
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from Copernicus Gesellschaft, Katlenburg-Lindau, Germany