Formation of "Southern Component Water" in the Late Cretaceous; evidence from Nd-isotopes

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doi: 10.1130/G31165.1
Author(s): Robinson, Stuart A.; Murphy, Daniel P.; Vance, Derek; Thomas, Deborah J.
Author Affiliation(s): Primary:
University College London, Department of Earth Sciences, London, United Kingdom
Other:
Texas A&M University, United States
University of Bristol, United Kingdom
Volume Title: Geology (Boulder)
Source: Geology (Boulder), 38(10), p.871-874. Publisher: Geological Society of America (GSA), Boulder, CO, United States. ISSN: 0091-7613 CODEN: GLGYBA
Note: In English. With GSA Data Repository Item 2010245. 29 refs.; illus., incl. sketch map
Summary: Constraining deep-ocean circulation during past greenhouse climatic periods, such as the Cretaceous, is important for understanding meridional heat transfer processes, controls on ocean anoxia, and the relative roles of climate and tectonics in determining paleocirculation patterns. Ocean circulation models for the Late Cretaceous and early Paleogene suggest that significant deep-water production occurred in the Southern Ocean, but cannot constrain when this process commenced or what the temporal relationship was between opening tectonic gateways and Late Cretaceous climatic cooling. Nd-isotope data obtained from biogenic apatite (fish teeth and bones) are presented from lower bathyal and abyssal sites in the South Atlantic and Indian Oceans. During the mid-Cretaceous, relatively radiogenic Nd-isotope values suggest that deep-water circulation in these basins was sluggish with inputs likely dominated by seawater-particle exchange processes and, possibly, easily weathered volcanic terranes. In the Campanian-Maastrichtian the Nd-isotopic composition of proto-Indian and South Atlantic deep waters became less radiogenic, suggesting the onset of deep-water formation in the Southern Ocean (Southern Component Water, SCW), consistent with Paleogene reconstructions and ocean circulation models. A combination of Southern Hemisphere cooling and the opening of tectonic gateways during the Campanian likely drove the onset of SCW.
Year of Publication: 2010
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; Apatite; Atlantic Ocean; Biochemistry; Biostratigraphy; Bones; Chordata; Climate change; Cooling; Cores; Cretaceous; DSDP Site 511; DSDP Site 530; Deep Sea Drilling Project; Deep-sea environment; Deep-water environment; Gascoyne abyssal plain; Geochemical indicators; Geochemistry; IPOD; Indian Ocean; Isotopes; Leg 123; Leg 185; Leg 71; Leg 75; Marine environment; Marine sediments; Mesozoic; Metals; Neodymium; North Pacific; Northwest Pacific; ODP Site 1149; ODP Site 766; Ocean Drilling Program; Pacific Ocean; Paleo-oceanography; Paleocirculation; Paleoclimatology; Paleogeography; Phosphates; Pisces; Radioactive isotopes; Rare earths; Sediments; South Atlantic; Southern Component Water; Teeth; Upper Cretaceous; Vertebrata; Walvis Ridge; West Pacific
Coordinates: S510017 S510017 W0465818 W0465818
S191116 S191115 E0092310 E0092308
N312030 N312030 E1432100 E1432100
S195556 S195555 E1102715 E1102714
Record ID: 2010090896
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