Boletín de la Sociedad Geológica Mexicana Volumen 74, núm. 2, A110522, 2022 http://dx.doi.org/10.18268/BSGM2022v74n2a110522

Estratigrafía y evolución estructural del Bloque de Coahuila, noreste de México

Stratigraphy and structural evolution of the Coahuila Block, northeastern Mexico

Samuel Eguiluz y de Antuñano^1,*

¹ Rinconada Precolombina, Bonampak 103, 04700, CDMX, México.

* Autor para correspondencia: (S. Eguiluz y de Antuñano) This email address is being protected from spambots. You need JavaScript enabled to view it.

Cómo citar este artículo:

Eguiluz y de Antuñano, S., 2022, Estratigrafía y evolución estructural del Bloque de Coahuila, noreste de México: Boletín de la Sociedad Geológica Mexicana, 74 (2), A110522. http://dx.doi.org/10.18268/BSGM2022v74n2a110522

Manuscrito recibido: 28 de Junio de 2021; Manuscrito corregido: 11 de Febrero de 2022; Manuscrito aceptado: 6 de Mayo de 2022.

ABSTRACT

The Coahuila Block has marine and continental rocks from the Paleozoic to the Recent, which outcrop in a vast region of northeastern Mexico. This work provides surface and subsurface data from confirm the presence of Nazas arc on this block. Stratigraphic sections describ the transgressive process of marine flooding on this block during the Aptian and a thick deposit of limestone, dolostone and evaporitic during the Albian and lower Cenomanian. The stratigraphic succession from the Upper Cretaceous is composed of the gradual passage among the Indidura, Parras, Cerro del Pueblo and the Cerro Huerta formations and the Soledad beds, all of them as foreland facies, with ~1000 m thickness, these rocks show a stratigraphic condensation on this block compared to similar stratigraphic successions in neighboring the Sabinas, Central Mexico and Chihuahua basins, which has thickness than more 2000 m same age rocks. In this work structural data are confronted with previous ideas that considered a soft deformation affected by normal-type faults. In the Coahuila Block three structural styles are distinguished: one of them closely related to broad curvature folds, other style composes by narrow and long folds with reverse faults, this style is restricted at the austral border of the Coahuila Block, which are tectonically cover for the Parras nappe, this nappe covers pre-Aptian marginal sedimentary facies of this block, both structural groups are closely related to the orientation of the structures of the phase that deformed the mexican Orogen. The third style is composed by acute folds with a stepped geometry and associated by structural complexes with roughly oriented north-south axes, with opposite vergences and diverse faults. This last structural style has not a defined extension or shortening component and their deformation possibly is post-shortening to the deformation of the mexican Orogen. The data presented define the southwestern geographical border of the Coahuila Block.

Keywords: Coahuila platform, Nazas arc, stratigraphic condensed section.