The Permian Basin is a sedimentary basin largely contained in the western part of the U.S. state of Texas and the southeastern part of the state of New Mexico. It reaches from just south of Lubbock, Texas, to just south of Midland and Odessa, extending westward into the southeastern part of the adjacent state of New Mexico. It is so named because it has one of the world's thickest deposits of rocks from the Permiangeologic period. The greater Permian Basin comprises several component basins: of these, Midland Basin is the largest, Delaware Basin is the second largest, and Marfa Basin is the smallest. The Permian Basin extends beneath an area approximately 250 miles (400 km) wide and 300 miles (480 km) long.