desolate rocky plateau of the Sahara, northwestern Libya. Located mostly in Tripolitania, it occupies an area measuring about 275 mi (440 km) by 190 mi. Its bare rock outcrops reach a height of about 2,700 ft (825 m). Wells are drilled for petroleum, which was discovered in the region in 1976. Some phosphates have also been discovered. The region's name is Arabic for “red stony plateau.”