New Mexico Geological Society Annual Spring Meeting — Abstracts

The Rio Grande Rift is a major Cenozoic continental rift zone that extends south from southern Colorado through Northern Mexico. North of central New Mexico the rift is a narrow feature at the edge of the southern Rocky Mountains. South of central New Mexico the rift widens significantly, forming multiple basins and ranges. The Albuquerque Basin is located in the narrow section of the rift. The Jornada del Muerto Basin and the Tularosa Basin, separated by the San Andres and Oscura Mountains, are located in wider region of the rift. Models of the Albuquerque and Jornada del Muerto Basins have been constructed using seismic and gravity constraints. New gravity data will be used to refine existing models to further constrain fault geometry in the basins. Significantly less modeling has been done on the Tularosa Basin. We present preliminary results for two and a half dimensional Talwani gravity models constructed across the southeast flank of the Oscura Mountains into the northern Tularosa Basin using Pan American Center for Earth and Environmental Studies (PACES) gravity data and density data from wells. These models are used to constrain the presence of a major normal fault and provide additional constraints on the subsurface geometry of the region. We hope these models will provide insight into the formation and relationship of narrow rift zones and “basin and range” style extensional provinces.