Southwestern New Mexico has scattered shelf deposits of Middle Cambrian, Ordovician, Lower and Middle Silurian, and Upper Devonian. During Mississippian time the Caballero, Pedregosa, and Orogrande basins began to develop. After an erosional period Pennsylvanian beds were deposited in these and the San Mateo and Lucero basins. Orogrande basin ended after deposition of Wolfcampian beds. During mid-Permian small local evaporite basins developed scattered in a shallow epicontinental sea which was periodically flooded by redbed detritus from the north. Some Triassic redbeds were deposited. In Early Cretaceous, sediments were deposited in the southwest with volcanics in the southwesternmost part. Upper Cretaceous strata covered most of the area. There is no petroleum production to date but shows are reported in Otero County.