Tectonically restricted deep-ocean circulation at the end of the Cretaceous greenhouse

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doi: 10.1016/j.epsl.2013.03.019
Author(s): Voigt, Silke; Jung, Claudia; Friedrich, Oliver; Frank, Martin; Teschner, Claudia; Hoffmann, Julia
Author Affiliation(s): Primary:
Goethe-Universität Frankfurt, Institute of Geosciences, Frankfurt, Germany
Other:
Helmholtz Centre for Ocean Research Kiel, Germany
Volume Title: Earth and Planetary Science Letters
Source: Earth and Planetary Science Letters, Vol.369-370, p.169-177. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0012-821X CODEN: EPSLA2
Note: In English. Supplemental information/data is available in the online version of this article. 69 refs.; illus., incl. sketch maps
Summary: The evolution of global ocean circulation toward deep-water production in the high southern latitudes is thought to have been closely linked to the transition from extreme mid-Cretaceous warmth to the cooler Cenozoic climate. The relative influences of climate cooling and the opening and closure of oceanic gateways on the mode of deep-ocean circulation are, however, still unresolved. Here we reconstruct intermediate- to deep-water circulation for the latest Cretaceous based on new high-resolution radiogenic neodymium (Nd) isotope data from several sites and for different water depths in the South Atlantic, Southern Ocean, and proto-Indian Ocean. Our data document the presence of markedly different intermediate water Nd-isotopic compositions in the South Atlantic and Southern Ocean. In particular, a water mass with a highly radiogenic Nd isotope signature most likely originating from intense hotspot-related volcanic activity bathed the crest of Walvis Ridge between 71 and 69 Ma, which formed a barrier that prevented deep-water exchange between the Southern Ocean and the North Atlantic basins. We suggest that the Cenozoic mode of global deep-ocean circulation was still suppressed by tectonic barriers in the latest Cretaceous, and that numerous, mostly regionally-formed and sourced intermediate to deep waters supplied the deep ocean prior to 68 million yr ago. Abstract Copyright (2013) Elsevier, B.V.
Year of Publication: 2013
Research Program: DSDP Deep Sea Drilling Project
IPOD International Phase of Ocean Drilling
ODP Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Atlantic Ocean; Cretaceous; DSDP Site 525; Deep Sea Drilling Project; Deep-water environment; Exmouth Plateau; Ferromanganese crusts; Greenhouse effect; IPOD; Indian Ocean; Isotope ratios; Isotopes; Leg 113; Leg 122; Leg 74; Maud Rise; Mesozoic; Metals; Nd-144/Nd-143; Neodymium; North Atlantic; ODP Site 690; ODP Site 762; Ocean Drilling Program; Ocean circulation; Paleo-oceanography; Paleoclimatology; Rare earths; Reconstruction; South Atlantic; Southern Ocean; Stable isotopes; Tectonics; Walvis Ridge; Weddell Sea
Coordinates: S290415 S290414 E0025908 E0025907
S195315 S195314 E1121515 E1121514
S650938 S650937 E0011218 E0011218
Record ID: 2013070460
Copyright Information: GeoRef, Copyright 2017 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands