Facies and paleoenvironmental analyses of two stratigraphic sections in the El Azogue, region, Sonora, Mexico

This paper presents the analysis of facies and paleoenvironments of two stratigraphic sections at the El Azogue locality the Plutarco Elías Calles dam (approximately 2 km to the east of San Pedro de la Cueva, Sonora, Mexico). The facies analysis consisted of the identification of allochemicals present in both sections describing the textural and compositional features in the analyzed samples. Both sections show a certain compositional homogeneity; however, systematic changes occur throughout the sections. The Cerro El Azogue section exhibits greater lithological variation toward its upper part. The Arroyo El Azogue section shows marked variations in the lower and middle strata, with progressive increases in the abundance of brachiopods, cortoids, and intraclasts. The facies correspond to supratidal, intertidal, and subtidal sedimentary environments.