Late Paleozoic Foreland Deformation in Northern Mexico: Paleogeographic and Tectonic Implications: ABSTRACT

Abstract

Deformation in north-central Mexico reflects the existence of an actively evolving foreland basin during the late Paleozoic. The Pedregosa and Orogrande basins formed the northern extensions of this north-northwest-trending foreland basin, which was flanked on the north and west by several large block uplifts. Deformation along the southeastern margin of the basin, in Coahuila, is postulated to represent part of a foreland fold-thrust belt, while structures in Chihuahua and adjacent parts of New Mexico and Texas are related to basement-involved block uplifts. The unconformities, sedimentation patterns and deformation styles of several localities in Chihuahua, southern New Mexico, and west Texas indicate similar, but not necessarily time-equivalent, deformational histories Uplift began in Late Mississippian and culminated between latest Pennsylvanian (in the north) and Late Permian (in the south). The geographic distribution and sequential timing of deformation are consistent with our knowledge of the Ouachita system in the U. S. The distribution of the fold-thrust belt and basement-involved uplifts of the Ouachita foreland in northern Mexico is not only similar to other parts of the Ouachita system but also to portions of the Laramide in the northern Rocky Mountains. These similarities and the distribution of late Paleozoic calc-alkaline igneous rocks in the region suggest that a subduction zone and associated magmatic arc were present in eastern Mexico during the late Paleozoic. End_of_Article - Last_Page 262------------