Tibesti Mountains - Geography

Geography

The mountains are the largest and highest range in the central Sahara, formed by a volcanic group. Most are inactive volcanoes, but the Smithsonian Institution lists four potentially active volcanos. The toponymy of the Tibesti massif is derived from the Arabic and Teda-daza languages of the Toubou people and is used throughout the region. The term ehi refers to peaks, rocky hills, emi to larger mountains or mountainous regions; ehra to calderas. The term Tarso designates a high plateau or gently-sloping mountainsides; for example the Ehi Mosgau is a 3,100 m (10,200 ft) Stratovolcano with a small summit area, near Tarso Voon. The Ehra Kohor is a caldera on the Emi Koussi summit.

The highest peak in the mountains is Emi Koussi, (3,415 m (11,204 ft)). Other summits include Kegueur Terbi (3,376 m (11,076 ft)), Tarso Taro (3,325 m (10,909 ft)), the potentially active volcano Tarso Toussidé (3,265 m (10,712 ft)) and Tarso Voon (3,100 m (10,200 ft)). The peak Bikku Bitti, located in northern area, is the highest mountain in Libya. While the high peaks themselves are all constituted of volcanic material, the mountains stand on broad uplifted area caused by a mantle plume. The intense activity of the volcanism began as early as the Oligocene, though the major products that mark its surface date from Lower Miocene to the Quaternary period. It shows as a key example of continental hot spot volcanism. In several areas of the mountains are hot springs and solfataras, most pronounced geothermal features are in the Soborom solfatara field on the north-western flank of Tarso Voon volcano.

The basement of the mountains is Precambrian schist, overlaid with Paleozoic sandstone, all capped by Paleogene and Pleistocene outpourings of basalt.