Geology of the El Teguachi area, State of Sonora, Mexico

Abstract

The study area is located in north-central Sonora, 150 km northeast of Hermosillo. Lower-Middle Proterozoic to Holocene rocks occur in the area.

The Precambrian rocks are among the southernmost ones of this age to crop out in Sonora. They include gneiss and schist (origin age of 1,800 Ma and metamorphism age of 1,650 Ma), granodiorite (1 ,700 Ma) and granite (1,100 Ma). The Paleozoic section is composed of a Cambrian (?) orthoquartzite. The Mesozoic consists of volcanic, volcano-sedimentary, and sedimentary rocks of Jurassic and Cretaceous age. The Tertiary comprises intrusive, volcanic, and sedimentary rocks.

Volcanic and volcano-sedimentary rocks of Lower-Middle Jurassic (?) and Oxfordian ages, respectively, may form the southeastern part of a magmatic arc. Synorogenic deposits of the El Tuli formation record the beginning of the Upper Cretaceous earliest tectonism (Cenomanian-Maastrichtian), which was accompanied by a penecontemporaneous magmatism of a kind that is widespread in Sonora... In order to continue, download full text in PDF.