T342 Recent Advances in the Study of the Laramide Orogeny and Related Processes in Mexico and the Southern United States

Thursday, 9 October 2008
8:00 AM - 12:00 PM

Evidence of Basement Inversion during the Laramide Orogeny in the Sabinas Basin Area, Coahuila, Mexico

Paper number: T342-2
Program: Technical Sessions
Time: 8:20 AM – 8:35 AM

Authors

Abstract

Major basin inversion in the southwestern margin of North America during the end of Cretaceous and beginning of Paleogene time (80-40 My), is one of several features that have been used as evidence of the Laramide deformation. Nevertheless, the extension of this orogenic belt towards Mexico is controversial.

Since the middle part of the last century, multiple works have focused on structural and tectonic analyzes in northeastern Mexico, having documented that the Laramide Orogeny shows typical features of thin skinned and not major evidences of thick skinned deformation as it was characterized for the Laramide region in North America. Recently, more detailed structural analysis in the southern part of the Sabinas and La Popa basins, in the hinterland region of the Sierra Madre Oriental fold thrust belt (Galeana and Aramberri areas), and through the San Marcos fault in central Coahuila, show strong evidence that inversion of basement blocks occurred at the end of the Laramide orogeny in northeastern Mexico. The inversion of basement blocks through reactivation of ancient Triassic-Jurassic faults in central Sabinas basin, has been dated using syn to post-tectonic pluton ages. The ages (40Ar-39Ar) constrain the inversion event to have occurred between 46-41 My, and the orogenic deformation also ended for this region at the same time.