The Triassic/Jurassic boundary and the Jurassic stratigraphy and biostratigraphy of northern Sonora, northwest Mexico
The Triassic and Jurassic geology of northern Sonora encompasses important events that are linked to the late Paleozoic history of the region. The fossiliferous El Antimonio Group in the Sierra del Álamo includes the upper Permian-Triassic An - timonio, and Río Asunción formations and the Hettangian...
| Autores: | , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2017 |
| País: | México |
| Institución: | Universidad Nacional Autónoma de México |
| Repositorio: | Redalyc-UNAM |
| OAI Identifier: | oai:redalyc.org:94353719011 |
| Acceso en línea: | https://www.redalyc.org/articulo.oa?id=94353719011 https://www.redalyc.org/journal/943/94353719011/ https://www.redalyc.org/journal/943/94353719011/html/ https://www.redalyc.org/journal/943/94353719011/94353719011.epub https://www.redalyc.org/journal/943/94353719011/movil |
| Access Level: | acceso abierto |
| Palabra clave: | Ciencias de la Tierra Triassic Jurassic biostratigraphy Cucurpe Formation El Antimonio Group |
| Sumario: | The Triassic and Jurassic geology of northern Sonora encompasses important events that are linked to the late Paleozoic history of the region. The fossiliferous El Antimonio Group in the Sierra del Álamo includes the upper Permian-Triassic An - timonio, and Río Asunción formations and the Hettangian-Sinemurian Sierra de Santa Rosa Formation. These formations consist of upward-fining sequences from I to XIV that represent fluvial to shallow and deep marine environments of depo - sition. The Triassic/Jurassic boundary in this region is a hiatus represented by a dis - conformity between sequence IX of the Río Asunción formations and sequence X of the Sierra de Santa Rosa Formation. The shallow to deep marine succession of the Sierra de Santa Rosa composes the upper part of the Sierra de Santa Rosa Formation that ranges in age from late Sinemurian to early Pliensbachian. Ages of the Permian to Triassic plutonic rocks of northwesternmost Sonora, the Mojave Desert and the Jurassic continental mar - gin Nazas arc that crossed through north - ern Sonora, are also well recorded by igneous clasts and detrital zircon grains that have been dated from the El Antimo - nio Group and other Jurassic formations of this region. The upper Oxfordian-low - er Tithonian Cucurpe Formation in north-central Sonora recorded the onset of continental extension and incursion of marine waters from the Gulf of Mexico into northwestern Mexico, once activity of the Jurassic magmatic arc ended. |
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