Cenozoic sedimentation and paleotectonics of north-central New Mexico: Implications for initiation and evolution of the Rio Grande rift

The Rio Grande rift is one of the major late Cenozoic continental rifts of the world, sharing most geophysical, geochemical, and geological characteristics with other rifts. Cenozoic evolution of the rift was synchronous with lithospheric plate interactions along and under the western North American margin: Paleocene-Eocene: Laramide primarily amagmatic compression related to flat-slab subduction; Oligocene: intermediate to silicic volcanism related to collapse of the slab; Miocene to present: rifting related to complex plate interactions overprinted on the previous history. Cenozoic paleogeographic and paleotectonic characteristics are consistent with a passive-mantle model of rifting. North-central New Mexico provides a unique opportunity to constrain models for rift initiation and evolution. It is one of the few locations within any rift where excellently exposed pre-rift and syn-rift basin fill has been studied thoroughly enough to allow detailed paleogeographic reconstruction for almost the entire Cenozoic. -from Authors