Depositional sequences and ammonoid assemblages in the upper Cenomanian-lower Santonian of the Iberian Peninsula (Spain and Portugal)
Segura, M. (Universidad de Alcalá. Grupo de Investigación IBERCRETA)
Barroso-Barcenilla, F. (Universidad Complutense de Madrid. Departamento de Paleontología)
Callapez, Pedro Miguel (Universidade de Coimbra. Departamento de Ciências da Terra)
García-Hidalgo, J. (Universidad de Alcalá. Grupo de Investigación IBERCRETA)
Gil Gil, Javier (Universidad de Alcalá. Grupo de Investigación IBERCRETA)
Universidade de Coimbra. Centro de Geofísica

Date:	2014
Abstract:	A clear relationship exists between eustatic sea-level rises and falls recorded as cyclical depositional sequences and ammonite faunas during the Cenomanian-Santonian in the Iberian and West Portuguese basins. Most of the faunal turnovers correlate with stratigraphic intervals related to marine transgressions, maximum flooding of the shelf (locally associated to anoxic events), and marine regressions. Specifically, within each depositional sequence, three distinct and identical events of morphological change occur, involving ammonoids belonging to different groups. Transgressive sediments are characterized by moderately ornamented, inflated and evolute morphologies, which are replaced by smooth, involute and compressed oxycones (the most hydrodynamic shells) during maximum flooding (and to a lesser extent at the early highstand) of the sequences. The latter morphologies in turn are replaced by coarsely ornamented and evolute shells during late highstands. We conclude that ammonoid faunal analysis can be used to trace sea-level changes and provides an additional tool for sequence stratigraphy.
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, sempre i quan aquestes es distribueixin sota la mateixa llicència que regula l'obra original i es reconegui l'autoria.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	Depositional sequences ; Ammonoid assemblages ; Upper Cenomanian-lower Santonian ; Spain ; Portugal
Published in:	Geologica acta, Vol. 12, Núm. 1 (March 2014) , p. 19-27, ISSN 1696-5728

Adreça alternativa: https://raco.cat/index.php/GeologicaActa/article/view/275585
Adreça alternativa: https://revistes.ub.edu/index.php/GEOACTA/article/view/105.000002056
DOI: 10.1344/105.000002056

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