Cretaceous deep-water formation in the Indian sector of the Southern Ocean

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doi: 10.1029/2011PA002198
Author(s): Murphy, Daniel P.; Thomas, Deborah J.
Author Affiliation(s): Primary:
Texas A&M University, Department of Oceanography, College Station, TX, United States
Volume Title: Paleoceanography
Source: Paleoceanography, 27(1). Publisher: American Geophysical Union, Washington, DC, United States. ISSN: 0883-8305 CODEN: POCGEP
Note: In English. 77 refs.; illus., incl. 3 tables
Summary: The role that meridional overturning circulation (MOC) patterns played in poleward heat transport during the extreme warmth of the Early to Late Cretaceous is a fundamental and unresolved question in climate dynamics. In order to address this question we must determine where deep waters formed, and how they may have circulated during periods of extreme warmth. Here we present late Albian through Maastrichtian (105 to 65 Ma) Nd isotope records from Deep Sea Drilling Project (DSDP) and Ocean Drilling Program (ODP) sites in the proto-Indian Ocean and the tropical Pacific. Comparison of these data with previously published records indicates deep-water formation in the Indian sector of the Southern Ocean began at least ∼105 Ma, extending the record of high-latitude convection back into the Early Cretaceous prior to the peak warmth of the mid-Cretaceous. The growing body of data supports a mode of MOC in part characterized by high-latitude downwelling during the peak of greenhouse warmth of the Mesozoic and Cenozoic. However, this mode of MOC likely was characterized by numerous locations of deep convection that were regionally important, but not significant in terms of a globally overturning circulation due to paleogeographic and bathymetric barriers.
Year of Publication: 2012
Research Program: ODP Ocean Drilling Program
Key Words: 02 Geochemistry; 12 Stratigraphy, Historical Geology and Paleoecology; Albian; Argo abyssal plain; Climate change; Cretaceous; Deep-water environment; Exmouth Plateau; Gascoyne abyssal plain; Greenhouse effect; Indian Ocean; Isotope ratios; Isotopes; Kerguelen Plateau; Leg 122; Leg 123; Leg 183; Leg 198; Lower Cretaceous; Maestrichtian; Marine environment; Mass spectra; Mesozoic; Metals; Nd-144/Nd-143; Neodymium; North Pacific; Northwest Pacific; ODP Site 1138; ODP Site 1208; ODP Site 763; ODP Site 765; ODP Site 766; Ocean Drilling Program; Ocean circulation; Pacific Ocean; Paleo-oceanography; Paleobathymetry; Paleoclimatology; Paleoenvironment; Paleogeography; Paleolatitude; Rare earths; Shatsky Rise; Southern Ocean; Spectra; Stable isotopes; Thermal ionization mass spectra; Tracers; Upper Cretaceous; West Pacific
Coordinates: S203512 S203511 E1121232 E1121231
Record ID: 2013008066
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