Lower Aptian ammonite and carbon isotope stratigraphy in the eastern Prebetic Domain (Betic Cordillera, southeastern Spain)

Authors

  • J.A. MORENO BEDMAR Departamento de Paleontología, Instituto de Geología, Universidad Nacional Autónoma de México. Ciudad Universitaria, Delegación Coyoacán, 04510, México, D.F., México.
  • M. COMPANY Departamento de Estratigrafía y Paleontología, Facultad de Ciencias, Universidad de Granada. Avenida Fuentenueva s/n, 18002 Granada, Spain.
  • J. SANDOVAL Departamento de Estratigrafía y Paleontología, Facultad de Ciencias, Universidad de Granada. Avenida Fuentenueva s/n, 18002 Granada, Spain.
  • J.M. TAVERA Departamento de Estratigrafía y Paleontología, Facultad de Ciencias, Universidad de Granada. Avenida Fuentenueva s/n, 18002 Granada, Spain.
  • T. BOVER-ARNAL Département de Géosciences, Université de Fribourg. Chemin du Musée 6, 1700, Fribourg, Switzerland.
  • R. SALAS Departament de Geoquímica, Petrologia i Prospecció Geològica, Universitat de Barcelona (UB). Martí i Franquès s/n, 08028 Barcelona, Spain.
  • G. DELANOY Département des Sciences de la Terre, Univers ité de Nice-Sophia Antipolis. 28 Avenue Valrose F-06100 Nice, France.
  • F.J.-M.R. MAURRASSE Department of Earth Sciences, Florida International University. 11200 S.W. 8th street, Miami, FL 33199, United States.
  • R. MARTÍNEZ Departament de Geologia (Paleontologia), Universitat Autònoma de Barcelona (UAB). Edifi ci C. 08193-Bellaterra, Spain.

Keywords:

Ammonites, Lower Aptian, OAE 1a, Biostratigraphy, Prebetic Domain, Southeastern Spain

Abstract

Major global palaeobiologic and palaeoenvironmental changes occurred during the Early Aptian. Precise dating and timing of the different events is crucial to determine possible cause-effect relationships between them. In this regard, the combination of biostratigraphic and chemostratigraphic data can provide a very useful tool for time control. So far attempts to correlate the Lower Aptian carbon isotope record and the ammonite zonation yielded contradictory conclusions.In this paper, we present the results of an integrated analysis of the ammonite stratigraphic distribution and highresolution carbon isotope profi les from Lower Aptian sections of the eastern Prebetic Domain (Betic Cordillera, southeastern Spain). We recognized, in ascending order, the Deshayesites oglanlensis, Deshayesites forbesi, Deshayesites deshayesi, and Dufrenoyia furcata Zones. This succession is the same as that recently identifi ed in the eastern Iberian Chain, and it closely correlates with both standard Mediterranean and Boreal zonations. The carbon isotope record displays the trends globally recognized for the Early Aptian, with two long positive shifts separated by a pronounced negative excursion. Calibration of this isotopic record with the ammonite zonation shows that the age of OAE 1a, which corresponds to the negative excursion and subsequent positive shift, is constrained to the middle/upper part of the Deshayesites forbesi Zone.

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Published

2012-12-21

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