A large number of late-Pleistocene to Holocene basaltic cones, lava flows, and maars occur along a roughly 50-km-long NE-SW trend on the Segererua and Rusarus Plateaus and areas to the SW. This volcanic region is located well E of the East African Rift, S of the massive Marsabit shield volcano. The two plateaus host most of the vents and are bounded by the Milgis River to the N and the Merille River to the S. Other vents lie to the SW, east of the Kauro River, and another large area of basaltic lava flows lies to the W.