The Barrier Volcanic Complex is made of four different volcanic centers. It runs east to west between Lake Turkana and Lake Logipi. Barrier is ~12.5 miles (20 km) long and ~9 miles (15 km) wide. These volcanoes form a natural dam that separates the two lakes. Tuff cones are very common on the north and south sides of the volcanic complex. These cones, marked with sediments left from lakes, show that Lake Turkana and Lake Logipi were very high at one time. Much geothermal energy can be found on and around these volcanoes. There are also many faults located on the Barrier Volcanic Complex. Barrier has erupted nine times. Its last eruption was in 1921.
Sources of Information:
Dunkley, P.N., et al, "The geothermal activity and geology of the northern sector of the Kenya Rift Valley," British Geological Survey, Research Report SC/93/1, 185 pp., 1993.