Research paper
Upper Sinemurian: Obtusum and Oxynotum chronozones in Asturias, Spain. Ammonoids and correlation with other western European basins
MARÍA JOSÉ COMAS-RENGIFO
Departamento de Geodinámica, Estratigrafía y Paleontología, Facultad de Ciencias Geológicas, Universidad Complutense de Madrid, José Antonio Novais, 12, 28040 Madrid, Spain. mjcomas@ucm.es
Corresponding author
ANTONIO GOY
Departamento de Geodinámica, Estratigrafía y Paleontología, Facultad de Ciencias Geológicas, Universidad Complutense de Madrid, José Antonio Novais, 12, 28040 Madrid, Spain. angoy@ucm.es
LAURA PIÑUELA
Museo del Jurásico de Asturias (MUJA). Rasa de San Telmo, s/n. San Juan de Duz, 33328 Colunga (Asturias). Spain. lpinuela.muja@gmail.com
JOSÉ CARLOS GARCÍA-RAMOS
Museo del Jurásico de Asturias (MUJA). Rasa de San Telmo, s/n. San Juan de Duz, 33328 Colunga (Asturias). Spain. jcgramos.muja@gmail.com
LUIS CARLOS SUÁREZ VEGA
Museo del Jurásico de Asturias (MUJA). Rasa de San Telmo, s/n. San Juan de Duz, 33328 Colunga (Asturias). Spain.
RICARDO PAREDES
Museu da Ciência. MARE-Marine and Environmental Sciences Centre, Universidade de Coimbra, Portugal: ricardo.paredes@uc.pt
ABSTRACT
The chronostratigraphy, biosedimentation and, in particular, the ammonoid succession in several upper Sinemurian sections (Obtusum and Oxynotum chronozones) on the Asturias coast, between Playa de Peñarrubia (Gijón) and Playa de Vega (Ribadesella) are analyzed. With the exception of the lower boundary of the Obtusum chronozone, all chronostratigraphic units have been characterized with relatively good precision. In the Obtusum chronozone (Obtusum and Stellare subchronozones), seven species of Asteroceras followed each other through time (A. aff. confusum–A. confusum–A. obtusum–A. cf. margaritoides–A. stellare–A. blakei) and Aegasteroceras (A. sagittarium), locally associated with scarce Epophioceras, Xipheroceras, Promicroceras and Cymbites. The Denotatus subchronozone is characterized by the vertical succession of three species of Eparietites (E. undaries–E. impendens–E. glaber) associated to rare Promicroceras. In the Oxynotum chronozone, Palaeoechioceras, Gagaticeras (G. cf. exortum–G. gagateum) y Oxynoticeras (O. simpsoni) occur in the Simpsoni subchronozone and Oxynoticeras (O. oxynotum) is associated with Cheltonia (C. accipitris) in the Oxynotum subchronozone. Scarce Paroxynoticeras, and scarce Bifericeras and Gleviceras occur in the middle and upper parts of this subchronozone, respectively. From a paleobiogeographic perspective, the recorded ammonite succession is typical of the northwest European Province, albeit having some elements from the Mediterranean Province in the middle and upper parts of the Obtusum chronozone (Asteroceras cf. suevicum, E. glaber) and in the middle part of the Oxynotum chronozone (Paroxynoticeras salisburgense).
Key words: Biostratigraphy, biosedimentation, correlations, Lower Jurassic, palaeobiogeography.
How to cite: Comas-Rengifo, M.J., Goy, A., Piñuela, L., García-Ramos, J.C., Suárez Vega, L.C. & Paredes, R. 2021. El Sinemuriense superior: cronozonas Obtusum y Oxynotum en Asturias, España. Ammonoideos y correlación con otras cuencas del oeste de Europa. [Upper Sinemurian: Obtusum and Oxynotum chronozones in Asturias, Spain. Ammonoids and correlation with other western European basins]. Spanish Journal of Palaeontology, 36 (1), 19–50.
Received 20 May 2020, Accepted 25 July 2020, Published online: 22 March 2021
https://doi.org/10.7203/sjp.36.1.20306
(Spanish only)