Evolution of deep-ocean circulation during the opening of the Atlantic Ocean in the latest Cretaceous and Paleocene
Final Report Abstract
The aim of this project was to investigate changes in intermediate- and deep-water formation and exchange in the North and South Atlantic sub-basins during latest Cretaceous to Paleocene times (75-55 Ma). By analyzing the Nd isotope composition of authigenic sedimentary archives in different ocean drilling sites from paleo-water depths between 500 and 4500 m, we generated new deep and intermediate water radiogenic Nd isotope records (expressed as εNd values) to decipher the control of the opening Atlantic Ocean on ocean circulation and its linkages to the evolution of global climate. The main findings of the project include 1) an improved age control for the latest Cretaceousearly Paleogene interval at the Newfoundland margin (Site U1403), the Walvis Ridge (Site 1267) and the Rio Grande Rise (Site 517) by application of carbon isotope stratigraphy and its integration into available bio- and magnetostratigraphies and astrochronologies, 2) the closure of the early Paleogene data gap for εNd signatures in different North and South Atlantic sub-basins, and 3) the first documentation of a convergence of εNd signatures for all studied Atlantic sites 59 million years ago. During the Late Cretaceous and early Cenozoic, the Earth experienced prolonged climatic cooling most likely caused by decreasing volcanic activity and atmospheric CO2 levels. However, the causes and mechanisms of the subsequent major global warming culminating in the late Paleocene to Eocene greenhouse climate are still enigmatic. The convergence of εNd signatures 59 Ma ago is interpreted to represent a major intensification of deep-water exchange between the North and South Atlantic, which coincided with the turning point of the benthic foraminiferal deep-water temperature record that reflects the start of the early Paleogene warming. We propose that this intensification of the Atlantic overturning circulation in concert with increased atmospheric CO2 from continental rifting marked a climatic tipping point contributing to a more efficient distribution of heat over the planet. A second aspect of this observation is the necessity of an enhanced volumetric flow of deepand intermediate-water masses through the opening South Atlantic basins to decrease the influence of local weathering inputs and boundary change effects on the seawater Nd isotopic composition, which is identified as the main reason for the observed large local differences of εNd signatures in the Late Cretaceous Atlantic Ocean.
Publications
- IODP Expedition 342 Scientists (2013) Orbitally calibrated carbon-isotope stratigraphy of the Maastrichtian of U1403, IODP Expedition 342, Newfoundland. 11th International Conference on Paleoceanography (ICP11), Sitges
Batenburg, S, Friedrich, O, Moriya, K, Voigt, S, Hasegawa, T
- (2014) Atlantic Ocean Circulation during the Latest Cretaceous and Early Paleogene: Progressive Deep Water Exchange. American Geophysical Union, Fall Meeting 2014, PP13A-1382, San Francisco, USA
Batenburg, SJ, Voigt, S, Friedrich, O, Osborne, A, Frank, M
- (2014) Evolution of deep-ocean circulation during the opening of the Atlantic Ocean in the latest Cretaceous and Paleocene. Schriftenreihe der Deutschen Gesellschaft für Geowissenschaften, Vol.85, p.16; GeoFrankfurt 2014, Frankfurt
Batenburg, SJ, Voigt, S, Friedrich, O, Frank, M
- (2015) Atlantic Ocean circulation during the latest Cretaceous and early Paleogene: progressive deep water exchange. Conference “Climates of the past – lessons for the future”, Monte Verità, Ascona, Switzerland
Batenburg, S
- (2015) Atlantic Ocean Circulation during the Latest Cretaceous and Early Paleogene: Progressive Deep Water Exchange. GeoBerlin, Berlin
Batenburg, SJ, Voigt, S, Friedrich, O, Osborne, AH, Klein, T, Neu, C, Frank, M
- (2016) Evolution of deep water exchange in the Atlantic Ocean during the latest Cretaceous – early Paleogene. 12th International Conference on Paleoceanography (ICP 12), Utrecht, Netherlands
Batenburg, SJ, Voigt, S, Friedrich, O, Klein, T, Neu, C, Osborne, AH, Frank M
- (2016) Evolution of neodymium isotopic signature of seawater in the North Atlantic and Southern Hemisphere during the Late Cretaceous: implications for intermediate and deep circulation. Gondwana Research 36, 503–522
Moiroud M, Pucéat E, Donnadieu Y, Bayon G, Guiraud M, Voigt S, Deconinck J-F, Monna F
(See online at https://doi.org/10.1016/j.gr.2015.08.005) - 2017. Evolution of deep water exchange in the Atlantic Ocean during the latest Cretaceous–early Paleogene. Berichte der Geologischen Bundesanstalt (ISSN 107-8880), Band 120, Wien 2017. 10th International Symposium on the Cretaceous System. 21.-26.08.2017, Vienna, Austria
Batenburg, SJ, Voigt, S, Friedrich, O, Klein, T, Neu, C, Osborne, A, Frank, M.
- IODP Expedition 342 Scientists (2018) Late Maastrichtian carbon isotope stratigraphy and cyclostratigraphy of the Newfoundland Margin (Site U1403, IODP Leg 342). Newsletters on Stratigraphy 51, 245–260
Batenburg SJ, Friedrich O, Moriya K, Voigt S, Cournède C, Moebius I, Blum P, Bornemann A, Fiebig J, Hasegawa T, Hull PM, Norris RD, Röhl U, Sexton P, Westerhold T, Wilson PA
(See online at https://doi.org/10.1127/nos/2017/0398)
