Present-day volcanic activity in Africa is centered in and around the East African rift valley. Volcanos are found in Tanzania at Oldoinyo Lengai and in the Virunga range on the Zaire-Uganda border at Nyamlagira and Nyiragongo. But there is also volcanism in West Africa. Mount Cameroon (13,350 ft; 4,005 m) along with smaller volcanos in its vicinity, stand on the bend of Africa's West Coast in the Gulf of Guinea, and are the exception. They are the only active volcanos on the African mainland not in the rift valley.
However, extinct volcanos and evidence of their activity are widespread on the continent. The Ahaggar Mountains in the central Sahara contain more than 300 volcanic necks that rise above their surroundings in vertical columns of 1,000 ft or more. Also in the central Sahara, several hundred miles to the east in the Tibesti Mountains, there exist huge volcanic craters or calderas. The Trou au Natron is 5 mi (8 km) wide and over 3,000 ft (900 m) deep. In the rift valley, the Ngorongoro Crater in Tanzania, surrounded by teeming wildlife and spectacular scenery, is a popular tourist attraction. Volcanism formed the diamonds found in South Africa and Zaire. The Kimberley diamond mine in South Africa is actually an ancient volcanic neck.
Science EncyclopediaScience & Philosophy: Adrenoceptor (adrenoreceptor; adrenergic receptor) to AmbientAfrica - Origin Of Africa, Continental Drift, General Features, East African Rift System, Human Evolution