Lower Aptian (Lower Cretaceous) ammonites from the basal strata of the La Peña Formation of Nuevo León State, northeast Mexico: biochronostratigraphic implications
Detailed paleontological studies of the basal strata of the La Peña Formation from a stratigraphicsection of the State of Nuevo León, northeastern Mexico, reveal a rich ammonite assemblage representativeof the local biozone indicative of the uppermost level of the early Aptian corresponding to the D...
| Autores: | , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2008 |
| País: | México |
| Institución: | Universidad Nacional Autónoma de México |
| Repositorio: | Redalyc-UNAM |
| OAI Identifier: | oai:redalyc.org:57225109 |
| Acceso en línea: | https://www.redalyc.org/articulo.oa?id=57225109 |
| Access Level: | acceso abierto |
| Palabra clave: | Ciencias de la Tierra Mexico Ammonites early Aptian Lower Cretaceous La Peña Formation |
| Sumario: | Detailed paleontological studies of the basal strata of the La Peña Formation from a stratigraphicsection of the State of Nuevo León, northeastern Mexico, reveal a rich ammonite assemblage representativeof the local biozone indicative of the uppermost level of the early Aptian corresponding to the Dufrenoyiajustinae Taxon Range Zone. The Lower Aptian assignment of this Mexican biozone is corroborated byits distinctive ammonite assemblage characteristic of both uppermost early Aptian standard ammonitezones of the stage; namely the Dufrenoyia furcata Zone, of the tripartite Mediterranean standard scheme,and its equivalent Tropaeum bowerbankii Zone of the northeastern Europe bipartite scheme. Thus, inMexico, the shift of deposition from a shallow carbonate platform locally represented by facies of theCupido Formation, to the deeper facies of the La Peña Formation took place sometime during the lateearly Aptian and not in the late Aptian as previously assigned. To avoid diachronic interpretations of theCupido-La Peña formational contact, the ammonites analyzed in this study for biochronostratigraphicpurposes, were compared to other coeval assemblages reported from the basal strata of the La PeñaFormation on a regional scale |
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