 Ampato consists of three volcanic cones, which lie on top of an older eroded volcanic edifice.They were formed sequentially by extrusion of lava flows, but Ampato has also had explosive eruptions which have deposited ash, lapilli and pumice in the surrounding landscape.One young lava flow has been dated to 17,000 ± 6,000 years before present, but a summit lava dome is even younger, and Holocene ash layers in surrounding peat bogs may testify to the occurrence of recent eruptions.