Silali Volcano | John Seach



1.15 N, 36.23 E
summit elevation 1528 m
Shield volcano

Silali Volcano is located in the northern Kenyan rift valley. It contains a spectacular 8 x 5 km diameter summit caldera which formed 63,000 years ago. The steep caldera walls are up to 300 m high.

The summit of Silali volcano rises 800 m above the surrounding terrain. The floor of the surrounding plain slopes northward from an altitude of 800 m to 600 m towards Emuruangogolak.

Evolution of Silali Volcano
Early eruptions of Silali volcano formed a 500 m high lava shield. Construction of the shield was followed by eruption of Kapedo tuffs from pyroclastic cones on the western flanks. Eruption of Kapedo tuffs was followed by major eruption of summit trachytes which cover most of the western slopes. Lava was erupted from a fault, rather than from a cone.

Eruption of Katenmening basalts from fissures covered all of the western slopes. This stage was followed by development of three cones at the base of the east facing summit scarp. Lava flows from the cones extended northwards. The final stages of Silali volcano evolution involved the emplacement of Black Hills mounds on the upper eastern flanks of the mountain.

Geothermal activity is present in the caldera and upper eastern flanks. Some eruptions may have occurred a few hundred years ago.

Further reading
Macdonald, R., et al. "Petrogenesis of Silali volcano, Gregory Rift, Kenya." Journal of the Geological Society 152.4 (1995): 703-720.

Smith, M., et al. "Geochronology, stratigraphy and structural evolution of Silali volcano, Gregory Rift, Kenya." Journal of the Geological Society 152.2 (1995): 297-310.

McCall, G.J.H. and Hornung, G., 1972. A geochemical study of Silali volcano, Kenya, with special reference to the origin of the intermediate-acid eruptives of the Central Rift Valley. In Developments in Geotectonics (Vol. 7, pp. 97-113). Elsevier.

Silali Volcano Eruptions

5050 BC, 6050 BC, 7050 BC