Sedimentary evolution of an Aptian syn-rift carbonate system (Maestrat Basin, E Spain): effects of accommodation and environmental change

Authors

  • T. BOVER ARNAL Abteilung Geologie, Fakultät für Biologie, Chemie, und Geowissenschaften, UniversitÄt Bayreuth. Universitätsstr, 30, 95440, Bayreuth, Germany.
  • J.A. MORENO BEDMAR Departament de Geoquímica, Petrologia i Prospecció Geològica, Facultat de Geologia, Universitat de Barcelona. Martí i Franquès s/n, 08028, Barcelona, Spain.
  • R. SALAS Departament de Geoquímica, Petrologia i Prospecció Geològica, Facultat de Geologia, Universitat de Barcelona. Martí i Franquès s/n, 08028, Barcelona, Spain.
  • P.W. SKELTON Department of Earth and Enviromental Sciences, The Open University. Milton Keynes MK7, UK.
  • K. BITZER Abteilung Geologie, Fakultät für Biologie, Chemie, und Geowissenschaften, UniversitÄt Bayreuth. Universitätsstr, 30, 95440, Bayreuth, Germany.
  • E GILI FOLCH Departatment de Geologia, Facultat de Ciències, Universitat Autònoma de Barcelona. Edifici Cs, 08193, Bellaterra (Cerdanyola del Vallès), Spain.

Keywords:

Carbonate system, Sequence stratigraphy, OAE1a, Aptian, Iberian Chain

Abstract

We report an integrated study of an expanded and relatively complete syn-rift continental to epeiric marine succession of Aptian age, cropping out in the western Maestrat Basin (eastern Iberian Chain). Four transgressiveregressive sequences are recognized throughout this mixed carbonate-siliciclastic succession, with excellent age control provided by ammonite biostratigraphic data. The transgressive systems tracts consist mainly of alternations of marls and limestones rich in orbitolinids. The regressive systems tracts are essentially characterized by wave- and tidally influenced siliciclastic and carbonate deposits, and by the development of carbonate platforms with rudists, corals, orbitolinids and green algae. Carbon and oxygen isotope curves were established in order to identify the global d13C perturbations related to the Early Aptian Oceanic Anoxic Event (OAE1a). These perturbations commence with a horizon of coral rubble encrusted by Lithocodium aggregatum and Bacinella irregularis with widespread large-sized discoidal Palorbitolina lenticularis. Associated d18O values indicate high-frequency cooling-warming climatic cycles. The fault-controlled rapid syn-rift subsidence recorded during this stage was the most important factor in producing accommodation. However, the major transgressions, sea level falls and biotic changes recorded in the eastern Iberian Chain are in agreement with those registered in other contemporaneous basins of the Tethys. Thus, the resulting sedimentary succession faithfully reflects the major oceanographic and climatically-driven global changes that characterized this stage albeit within a context established by regional tectonics. Hence, this well-documented record of the evolution of an Aptian epicontinental sea provides a useful comparative case study for the analysis of other Aptian epeiric sedimentary successions.

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Published

2010-10-13

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Articles