Late Cretaceous changes in continental configuration: toward a better-ventilated ocean? - Archive ouverte HAL Access content directly
Conference Papers Year : 2017

Late Cretaceous changes in continental configuration: toward a better-ventilated ocean?

(1) , (2) , (3) , (2)
1
2
3

Abstract

Oceanic anoxic events (OAEs) are large-scale events of oxygen depletion in the deep ocean that happened dur- ing pre-Cenozoic periods of extreme warmth. Last global OAE occurred at the Cenomanian-Turonian boundary (OAE2) prior to the Late Cretaceous long term cooling. Ever since, and despite the occurrence of warming events, Earth no more experienced such large-scale anoxic conditions. Here we explore the role of major continental configuration changes occurring during the Late Cretaceous on oceanic circulation modes through numerical sim- ulations using a General Circulation Model (GCM), that we confront to existing neodymium isotope data ( " Nd). Except from a continuous deep-water production in the North Pacific, the simulations at 95 Ma and 70 Ma reveal major differences marked by a shift in the southern deep-water production sites from South Pacific at 95Ma to South Atlantic and Indian oceans at 70Ma. Our modelling results support an intensification of southern Atlantic deep-water production as well as a reversal of the deep-water fluxes through the Caribbean Seaway as the main causes of the decrease in " Nd values recorded in the Atlantic and Indian deep waters during the Late Cretaceous. We conclude that the change from a sluggish to a much more active circulation depicted by the model in the Atlantic from 95Ma to 70Ma may have driven the disappearance of OAEs after the Late Cretaceous.
Not file

Dates and versions

insu-01520795 , version 1 (11-05-2017)

Identifiers

  • HAL Id : insu-01520795 , version 1

Cite

Yannick Donnadieu, Emmanuelle Pucéat, François Guillocheau, Jean-François Deconinck. Late Cretaceous changes in continental configuration: toward a better-ventilated ocean?. European Geosciences Union General Assembly 2017, European Geosciences Union, Apr 2017, Vienne, Austria. pp.EGU2017-13996. ⟨insu-01520795⟩
145 View
0 Download

Share

Gmail Facebook Twitter LinkedIn More