Large amounts of basalt were deposited in the Rift valley on the north, east and south of the volcano through effusion and explosions during the early Holocene. A breached scoria cone that forms the summit of the mountain also erupted fluid olivine basalts, with some eruptions later than the period around 3,000 years ago when Lake Suguta dried out. Eruptions may have occurred around the same time as historical eruptions of the Barrier Volcano to the north.