Maria Fold and Thrust Belt - Geology

Geology

The Maria fold-and-thrust-belt is defined as the region where the compression that helped create the North American Cordillera – abruptly changed directions. North of the Maria fold-and-thrust-belt, the mountain ranges trend north-south, with east-west compression due to the subduction of the Farallon slab beneath western North America. At the Maria fold-and-thrust-belt, compressional deformation shifts to being generally north-south, with the front of the mountain ranges being defined by a roughly east-west line. This line then shifts gently to the east-southeast, where the Cordilleran deformation diffuses into a broad shear zone in northeastern Mexico.

Another notable feature that differentiates it from the rest of the Cordillera is that the deformation involves the rocks of the North American craton. Deformation in the remainder of the Cordillera only involves rocks that were part of the near-shore and offshore, sedimentary sequences.