 The dacitic Corinta deposits conversely were created during one large eruption which also left a crater on Ampato; it generated stratified thick tephra deposits which contain pumice embedded within ash-rich layers, and it is probably also the source of the pumice flow deposits on the south-southwestern flank.These contain dacitic pumice fragments in a matrix rich in ash and have thicknesses of more than in the few outcrops; much of this unit was likely eroded away by glacial activity.The central cone grew in the gap between the northern and southern edifice and consists of lava flows again of andesitic to dacitic composition.These flows are together maximally thick and one flow has been dated to 17,000 ± 6,000 years before present.