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Speijer, R. P.
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Speijer, R. P.
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- PublicationOpen AccessLatest Cretaceous climatic and environmental change in the South Atlantic region(2017)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;; ; ; ;Latest Maastrichtian climate change caused by Deccan volcanism has been invoked as a cause of mass extinction at the Cretaceous-Paleogene (K-Pg) boundary (~66.0 Ma). Yet late Maastrichtian climate and ecological changes are poorly documented, in particular on the Southern Hemisphere. Here we present upper Maastrichtian-lower Danian climate and biotic records from the Bajada del Jagüel (BJ) shelf site (Neuquén Basin, Argentina), employing the TEX86 paleothermometer, marine palynology (dinoflagellate cysts), and micropaleontology (foraminifera). These records are correlated to the astronomically tuned Ocean Drilling Program Site 1262 (Walvis Ridge). Collectively, we use these records to assess climatic and ecological effects of Deccan volcanism in the Southern Atlantic region. Both the TEX86-based sea surface temperature (SST) record at BJ and the bulk carbonate δ18O-based SST record of Site 1262 show a latest Maastrichtian warming of ~2.5–4°C, at 450 to 150 kyr before the K-Pg boundary, coinciding with the a large Deccan outpouring phase. Benthic foraminiferal and dinocyst assemblage changes indicate that this warming resulted in enhanced runoff and stratification of the water column, likely resulting from more humid climate conditions in the Neuquén Basin. These climate conditions could have been caused by an expanding and strengthening thermal low over the South American continent. Biotic changes in response to late Maastrichtian environmental changes are rather limited, when compared to the major turnovers observed at many K-Pg boundary sites worldwide. This suggests that environmental perturbations during the latest Maastrichtian warming event were less severe than those following the K-Pg boundary impact.92 48 - PublicationRestrictedThe Global Stratotype Sections and Points for the bases of the Selandian (Middle Paleocene) and Thanetian (Upper Paleocene) stages at Zumaia, Spain(2011-12)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;Schmitz, B.; Department of Geology, Lund University, SE-22362 Lund, Sweden ;Pujalte, V.; Department of Stratigraphy and Paleontology, University of the Basque Country, E-48080 Bilbao, Spain ;Molina, E.; Department of Earth Sciences, Zaragoza University, E-50009 Zaragoza, Spain ;Monechi, S.; Department of Earth Sciences, Florence University, 50121 Florence, Italy ;Orue-Etxebarria, X.; Department of Stratigraphy and Paleontology, University of the Basque Country, E-48080 Bilbao, Spain ;Speijer, R. P.; Department of Earth and Environmental Sciences, K.U. Leuven, B-3001 Leuven, Belgium ;Alegret, L.; Department of Earth Sciences, Zaragoza University, E-50009 Zaragoza, Spain ;Apellaniz, E.; Department of Stratigraphy and Paleontology, University of the Basque Country, E-48080 Bilbao, Spain ;Arenillas, I.; Department of Earth Sciences, Zaragoza University, E-50009 Zaragoza, Spain ;Aubry, M. P.; Department of Geology, Rutgers University, Piscatatway, NJ 08854 USA. ;Baceta, J. I.; Department of Stratigraphy and Paleontology, University of the Basque Country, E-48080 Bilbao, Spain ;Berggren, W. A.; Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA ;Bernaola, G.; Department of Mining and Metallurgic Engineering and Material Sciences, University of the Basque Country, E-48901 Barakaldo, Spain ;Caballero, F.; Department of Stratigraphy and Paleontology, University of the Basque Country, E-48080 Bilbao, Spain ;Clemmensen, A.; Department of Earth Sciences, Århus University, DK-8000 Århus C, Denmark ;Dinarès-Turell, J.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Dupuis, C.; Laboratoire de Géologie Fondamentale et Appliquée, Faculté Polytechnique de Mons, B-7000 Mons, Belgium ;Heilmann-Clausen, C.; Department of Earth Sciences, Århus University, DK-8000 Århus C, Denmark ;Orús, A. H.; Eguzkialde 13, E-20271 Irura, Gipuzkoa, Spain ;Knox, R.; British Geological Survey, Kingsley Durham Centre, Keyworth, Nottingham NG12 5GG, United Kingdom ;Martín-Rubio, M.; Department of Mining and Metallurgic Engineering and Material Sciences, University of the Basque Country, E-48901 Barakaldo, Spain ;Ortiz, S.; Department of Earth Sciences, Zaragoza University, E-50009 Zaragoza, Spain ;Payros, A.; Department of Stratigraphy and Paleontology, University of the Basque Country, E-48080 Bilbao, Spain ;Petrizzo, M. R.; Department of Earth Sciences, Milano University, 20133 Milano, Italy ;von Salis, K.; Via Maistra 9, CH-7513 Silvaplana, Switzerland ;Sprong, J.; Department of Earth and Environmental Sciences, K.U. Leuven, B-3001 Leuven, Belgium ;Steurbaut, E.; Department of Paleontology, Royal Belgian Institute of Natural Sciences, B-1000 Brussels, Belgium ;Thomsen, E.; Department of Earth Sciences, Århus University, DK-8000 Århus C, Denmark; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; The global stratotype sections and points for the bases of the Selandian (Middle Paleocene) and Thanetian (Upper Paleocene) stages have been defined in the coastal cliff along the Itzurun Beach at the town of Zumaia in the Basque Country, northern Spain. In the hemipelagic section exposed at Zumaia the base of the Selandian Stage has been placed at the base of the Itzurun Formation, ca. 49 m above the Cretaceous/ Paleogene boundary. At the base of the Selandian, marls replace the succession of Danian red limestone and limestone-marl couplets. The best marine, global correlation criterion for the basal Selandian is the second radiation of the important calcareous nannofossil group, the fasciculiths. Species such as Fasciculithus ulii, F. billii, F. janii, F. involutus, F.pileatus and F. tympaniformis have their first appearance in the interval from a few decimetres below up to 1.1 m above the base of the Selandian. The marker species for nannofossil Zone NP5, F. tympaniformis, first occurs 1.1 m above the base. Excellent cyclostratigraphy and magnetostratigraphy in the section creates further correlation potential, with the base of the Selandian occuring 30 precession cycles (630 kyr) above the top of magnetochron C27n. Profound changes in sedimentology related to a major sea-level fall characterize the Danian-Selandian transition in sections along the margins of the North Atlantic. The base of the Thanetian Stage is placed in the same section ca. 78 m above the Cretaceous/Paleogene boundary. It is defined at a level 2.8 m or eight precession cycles above the base of the core of the distinct clay-rich interval associated with the Mid-Paleocene Biotic Event, and it corresponds to the base of magnetochron C26n in the section. The base of the Thanetian is not associated with any significant change in marine micro-fauna or flora. The calcareous nannofossil Zone NP6, marked by the first occurrence of Heliolithus kleinpelli starts ca. 6.5 m below the base of the Thanetian. The definitions of the global stratotype points for the bases of the Selandian and Thanetian stages are in good agreements with the definitions in the historical stratotype sections in Denmark and England, respectively.293 30