Trabucho Alexandre, Joao et al. (2010): The Mid-Cretaceous North Atlantic nutrient trap; black shales and OAEs

Leg/Site/Hole:
ODP 210
DSDP 41
DSDP 41 367
ODP 210 1276
Identifier:
2013-034374
georefid

10.1029/2010PA001925
doi

Creator:
Trabucho Alexandre, Joao
Utrecht University, Department of Earth Sciences, Utrecht, Netherlands
author

Tuenter, Erik
Shell Technology India Private, India
author

Henstra, Gijs A.
author

van der Zwan, Kees J.
author

van de Wal, Roderik S. W.
author

Dijkstra, Henk A.
author

de Boer, Poppe L.
author

Identification:
The Mid-Cretaceous North Atlantic nutrient trap; black shales and OAEs
2010
Paleoceanography
American Geophysical Union, Washington, DC, United States
25
4
Organic-rich sediments are the salient marine sedimentation product in the mid-Cretaceous of the ocean basins formed in the Mesozoic. Oceanic anoxic events (OAEs) are discrete and particularly organic-rich intervals within these mid-Cretaceous organic-rich sequences and are defined by pronounced carbon isotope excursions. Marine productivity during OAEs appears to have been enhanced by the increased availability of biolimiting nutrients in seawater due to hydrothermal alteration of submarine basalts in the Pacific and proto-Indian oceans. The exact mechanisms behind the deposition of organic-rich sediments in the mid-Cretaceous are still a matter of discussion, but a hypothesis which is often put forward is that their deposition was a consequence of the coupling of a particular paleogeography with changes in ocean circulation and nutrient supply. In this study, we used a global coupled climate model to investigate oceanic processes that affect the interbasinal exchange of nutrients as well as their spatial distribution and bioavailability. We conclude that the mid-Cretaceous North Atlantic was a nutrient trap as a consequence of an estuarine circulation with respect to the Pacific. Organic-rich sediments in the North Atlantic were deposited below regions of intense upwelling. We suggest that enhanced productivity during OAEs was a consequence of upwelling of Pacific-derived nutrient-rich seawater associated with submarine igneous events.
English
Serial
Coverage:Geographic coordinates:
North:45.2400
West:-44.4700East: -20.0250
South:12.2913

Stratigraphy; Atlantic Ocean; black shale; Cape Verde Basin; clastic rocks; Community Climate System Model; Cretaceous; data processing; Deep Sea Drilling Project; digital simulation; DSDP Site 367; general circulation models; global; large igneous provinces; Leg 210; Leg 41; Mesozoic; Middle Cretaceous; Newfoundland Basin; North Atlantic; Northwest Atlantic; numerical models; ocean circulation; Ocean Drilling Program; oceanic anoxic events; ODP Site 1276; paleo-oceanography; paleogeography; sedimentary rocks; three-dimensional models; upwelling; velocity;

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