オルドイニョ・エブルル

Eburru volcano is elongated E-W perpendicular to the Gregory Rift NW of Lake Naivasha. The main edifice is eroded, but young partly vegetated rhyolitic domes occur on the E flank and are probably of Holocene age (Thompson and Dodson, 1963). Pleistocene phonolitic and trachytic lava flows are overlain by rhyolitic obsidian lava flows forming much of the N and NE slopes of the main massif. A prominent late-Pleistocene rhyolitic lava flow from a SE-flank vent extends almost to Lake Naivasha. Extensive fumarolic activity occurs at cinder cones and craters constructed along dominantly N-S faults cutting the massif.