The Global Stratotype Sections and Points for the bases of the Selandian (Middle Paleocene) and Thanetian (Upper Paleocene) stages at Zumaia, Spain

Birger Schmitz; Victoriano Pujalte; Eustoquio Molina; Simonetta Monechi; Xabier Orue-Etxebarria; Robert P. Speijer; Laia Alegret; Estibaliz Apellaniz; Ignacio Arenillas; Marie-Pierre Aubry; Juan-Ignacio Baceta; William A. Berggren; Gilen Bernaola; Fernando Caballero; Anne Clemmensen; Jaume Dinarès-Turell; Christian Dupuis; Claus Heilmann-Clausen; Asier Hilario Orús; Robert Knox; Maite Martín-Rubio; Silvia Ortiz; Aitor Payros; Maria Rose Petrizzo; Katharina von Salis; Jorinde Sprong; Etienne Steurbaut; Erik Thomsen

doi:10.18814/epiiugs/2011/v34i4/002

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Episodes 2011; 34(4): 220-243

Published online December 1, 2011

https://doi.org/10.18814/epiiugs/2011/v34i4/002

The Global Stratotype Sections and Points for the bases of the Selandian (Middle Paleocene) and Thanetian (Upper Paleocene) stages at Zumaia, Spain

Birger Schmitz¹, Victoriano Pujalte², Eustoquio Molina³, Simonetta Monechi⁴, Xabier Orue-Etxebarria², Robert P. Speijer⁵, Laia Alegret³, Estibaliz Apellaniz², Ignacio Arenillas³, Marie-Pierre Aubry⁶, Juan-Ignacio Baceta², William A. Berggren⁷, Gilen Bernaola⁸, Fernando Caballero², Anne Clemmensen⁹, Jaume Dinarès-Turell¹⁰, Christian Dupuis¹¹, Claus Heilmann-Clausen⁹, Asier Hilario Orús¹², Robert Knox¹³, Maite Martín-Rubio⁸, Silvia Ortiz³, Aitor Payros², Maria Rose Petrizzo¹⁴, Katharina von Salis¹⁵, Jorinde Sprong⁵, Etienne Steurbaut¹⁶, Erik Thomsen⁹

¹Department of Geology, Lund University, SE-22362 Lund, Sweden. Email: birger.schmitz@ geol.lu.se
²Department of Stratigraphy and Paleontology, University of the Basque Country, E-48080 Bilbao, Spain.
³Department of Earth Sciences, Zaragoza University, E-50009 Zaragoza, Spain.
⁴Department of Earth Sciences, Florence University, I-50121 Florence, Italy.
⁵Department of Earth and Environmental Sciences, K.U. Leuven, B-3001 Leuven, Belgium.
⁶Department of Geology, Rutgers University, Piscataway, NJ 08854, USA.
⁷Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA.
⁸Department of Mining and Metallurgic Engineering and Material Sciences, University of the Basque Country, E-48901 Barakaldo, Spain.
⁹Department of Earth Sciences, Århus University, DK-8000 Århus C, Denmark.
¹⁰Instituto Nazionale di Geofisica e Vulcanologia, Via di Vigna Murata 605, I-00142 Rome, Italy.
¹¹Laboratoire de Géologie Fondamentale et Appliquée, Faculté Polytechnique de Mons, B-7000 Mons, Belgium.
¹²Eguzkialde 13, E-20271 Irura, Gipuzkoa, Spain.
¹³British Geological Survey, Kingsley Durham Centre, Keyworth, Nottingham NG12 5GG, United Kingdom.
¹⁴Department of Earth Sciences, Milano University, I-20133 Milano, Italy.
¹⁵Via Maistra 9, CH-7513 Silvaplana, Switzerland.
¹⁶Department of Paleontology, Royal Belgian Institute of Natural Sciences, B-1000 Brussels, Belgium.

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

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.