Análisis de microfacies y datos micropaleontológicos de la transición Barremiano-Aptiano en la Sierra del Rosario, Durango, México
Por:
Barragán-Manzo R., Díaz-Otero C.
Publicada:
1 ene 2004
Resumen:
The detailed analysis of the microfacies succession on a stratigraphie sequence representative of the upper part of the Cupido Formation, cropping out in Durango State, provide additional data for the paleoecological and micropaleontological significance of the Barremian-Aptian transition in northeast Mexico. The stratigraphic section herein studied is composed of a series of deposits typical of a shallow carbonate platform, which was apparently exposed to different paleobathymetric changes of short duration and low magnitude through the Barremian-Aptian transition. The section is characterized by a rich micropaleontological association mainly composed by benthonic foraminifera of the families Ataxophragmiidae, Lituolidae, Textularidae, Orbitolinidae, Nezzazatidae (Subfamily Nezzazatinae) and Miliolidae. These foraminifera are commonly associated to calcareous algae, mollusk and ostracod fragments, pellets, and echinoid spines. The prevailing textural composition and allochemical content throughout the sedimentary facies succession are indicative of Standard Microfacies typical of different sites of deposition, which vary from lagoon or back-reef environments to sand bars or shoals, and into high energy environments in fore-reef positions. The limit of the Barremian Aptian transition in the area of study is defined by the first stratigraphic appearance of Palorbitolina cf. lenticularis (Blumenbach), and is coincident with an apparent short period of deepening of the deposition environment to a local extent.
Filiaciones:
Barragán-Manzo R.:
Instituto de Geología, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510 México, D. F., Mexico
Díaz-Otero C.:
Instituto de Geología y Paleontología, Vía Blanca y Carretera Central, 11000 La Habana, Cuba
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