The higher elevations of Coropuna consist of an ice cap and glaciated terrain but old lava flows with gentle slopes and blocky lava crop out from underneath the ice. Regions of hydrothermally altered rocks, lava flows, pyroclastic flows and areas covered by volcanic ash occur all around the mountain. Glacial activity has eroded these volcanic rocks, carving valleys into them or removing them altogether. This process created U-shaped valleys such as Buenavista, Cospanja and Tuilaqui on the southern flank, and glacial valleys such as Chaque, Mapa Mayo, Río Blanco, Torcom and Ullulo on the northern slopes. Glacial valleys of Coropuna are up to deep and long.