Depositional sequences and ammonoid assemblages in the upper Cenomanian-lower Santonian of the Iberian Peninsula (Spain and Portugal)

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 tra...

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Main Authors: M. SEGURA, F. BARROSO-BARCENILLA, P. CALLAPEZ, J.F. GARCÍA-HIDALGO, J. GIL-GIL
Format: Article
Language:English
Published: Universitat de Barcelona (UB), Geociències Barcelona (Geo3BCN), Institut de Diagnosi Ambiental i Estudis de l'Aigua (IDAEA), Universitat Autònoma de Barcelona (UAB) 2014-06-01
Series:Geologica Acta
Subjects:
Online Access:https://revistes.ub.edu/index.php/GEOACTA/article/view/10464
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author M. SEGURA
F. BARROSO-BARCENILLA
P. CALLAPEZ
J.F. GARCÍA-HIDALGO
J. GIL-GIL
author_facet M. SEGURA
F. BARROSO-BARCENILLA
P. CALLAPEZ
J.F. GARCÍA-HIDALGO
J. GIL-GIL
author_sort M. SEGURA
collection DOAJ
description 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.
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spelling doaj.art-e965fcf1efb04c639919ae942486181f2023-10-20T07:05:32ZengUniversitat de Barcelona (UB), Geociències Barcelona (Geo3BCN), Institut de Diagnosi Ambiental i Estudis de l'Aigua (IDAEA), Universitat Autònoma de Barcelona (UAB)Geologica Acta1696-57282014-06-01121Depositional sequences and ammonoid assemblages in the upper Cenomanian-lower Santonian of the Iberian Peninsula (Spain and Portugal)M. SEGURA0F. BARROSO-BARCENILLA1P. CALLAPEZ2J.F. GARCÍA-HIDALGO3J. GIL-GIL4Grupo de Investigación IBERCRETA, Universidad de Alcalá de Henares 28871 Alcalá de Henares, España – Spain.Departamento de Paleontología, Universidad Complutense de Madrid 28040 Madrid, España – Spain.Departamento de Ciências da Terra, Universidade de Coimbra 3000-272 Coimbra, Portugal. Centro de Geofísica, Universidade de Coimbra 3000-134 Coimbra, Portugal.Grupo de Investigación IBERCRETA, Universidad de Alcalá de Henares 28871 Alcalá de Henares, España – Spain.Grupo de Investigación IBERCRETA, Universidad de Alcalá de Henares 28871 Alcalá de Henares, España – Spain. 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. https://revistes.ub.edu/index.php/GEOACTA/article/view/10464Depositional sequencesAmmonoid assemblagesUpper Cenomanian-Lower SantonianSpainPortugal
spellingShingle M. SEGURA
F. BARROSO-BARCENILLA
P. CALLAPEZ
J.F. GARCÍA-HIDALGO
J. GIL-GIL
Depositional sequences and ammonoid assemblages in the upper Cenomanian-lower Santonian of the Iberian Peninsula (Spain and Portugal)
Geologica Acta
Depositional sequences
Ammonoid assemblages
Upper Cenomanian-Lower Santonian
Spain
Portugal
title Depositional sequences and ammonoid assemblages in the upper Cenomanian-lower Santonian of the Iberian Peninsula (Spain and Portugal)
title_full Depositional sequences and ammonoid assemblages in the upper Cenomanian-lower Santonian of the Iberian Peninsula (Spain and Portugal)
title_fullStr Depositional sequences and ammonoid assemblages in the upper Cenomanian-lower Santonian of the Iberian Peninsula (Spain and Portugal)
title_full_unstemmed Depositional sequences and ammonoid assemblages in the upper Cenomanian-lower Santonian of the Iberian Peninsula (Spain and Portugal)
title_short Depositional sequences and ammonoid assemblages in the upper Cenomanian-lower Santonian of the Iberian Peninsula (Spain and Portugal)
title_sort depositional sequences and ammonoid assemblages in the upper cenomanian lower santonian of the iberian peninsula spain and portugal
topic Depositional sequences
Ammonoid assemblages
Upper Cenomanian-Lower Santonian
Spain
Portugal
url https://revistes.ub.edu/index.php/GEOACTA/article/view/10464
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