Geologic structure of the northern margin of the Chihuahua trough: Evidence for controlled deformation during Laramide Orogeny

Abstract

In this article we studied the northern part of the Laramide foreland of the Chihuahua Trough. The purpose of this work is twofold; fi rst we studied whether the deformation involves or not the basement along crustal faults (thin-or thick-skinned deformation), and second, we studied the nature of the principal shortening directions in the Chihuahua Trough. In this region, style of deformation changes from motion on moderate to low angle thrust and reverse faults within the interior of the basin to basement involved reverse faulting on the adjacent platform. Shortening directions estimated from the geometry of folds and faults and inversion of fault slip data indicate that both basement involved structures and faults within the basin record a similar Laramide deformation style. Map scale relationships indicate that motion on high angle basement involved thrusts post dates low angle thrusting. This is consistent with the two sets of faults forming during a single progressive deformation with in -sequence -thrusting migrating out of the basin onto the platform.