Kilimanjaro is the largest of an E-W belt of about 20 volcanoes near the southern end of the East African Rift Valley. It is a triple stratovolcano with the youngest and central peak of Kibo being 7.5-8.7 miles (12-14 km) from Shira to the west and Mawenza to the east. Shira is topped by a broad plateau, perhaps a filled caldera, and erosion has cut deeply into a remnant rim. In contrast, Mawenzi's summit is a steep rocky peak surrounded by cliffs 1,600 ft.(0.5 km) to 4,900 ft.(1.5 km) high. Erosion has removed the original crater, and a great horseshoe shaped ridge opens to the northeast. Mile-deep gullies with 30-45 degree gradients make many places practically inaccessible. Massive series of radial and concentric dyke swarm make up more than 30-40 percent of the summit area of Mawenzi. Kibo's glacier-clad summit, the highest spot in Africa, is a 1.2 x 1.7 mile (1.9 x 2.7 km) caldera, with an inner crater nearly a mile (1.3 km) wide, and inside that a deep, 1,148 ft. (350 m) wide central pit. Nearly 250 satellitic cones occur on Kilimanjaro, most following SE and NW trends.
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