Kone

The Kone volcanic complex (also known as Gariboldi) is composed of a series of silicic calderas and young basaltic cinder cones and lava flows about 30 km SW of Fentale volcano in the Main Ethiopian Rift. As many as eight silicic calderas are accompanied by ignimbrite outflow sheets. Kone, the youngest caldera, is an elliptical 5 x 7.5 km structure trending E-W and oriented perpendicular to the rift. The rim rises about 100 m above the caldera floor; the eastern rim overlaps with a smaller elliptical caldera. Regional fissures trending roughly N-S cut across the caldera and its flanks. The youngest basalts were erupted during the first half of the 19th century from vents along a hinge line between the smaller eastern caldera (Korke) and the larger western one. A dark lava flow from a cone near the center of the southern caldera (Birenti), extended 12 km SW, where the caldera rim had been eroded, and surrounded older cones.