19.27 N, 97.47 W
summit elevation 3485 m
The volcanic region consists of scoria cones, tuff rings (Laguna Atexcac and Laguna Alchichica), tuff cones, lava domes (Derrumbadas, Cerro Pizarro), and lava flows of unknown age.
Several of the tuff rings, such as Laguna Atexcac and Laguna Alchichica, are filled with lakes. A major explosive eruption produced the Quetzalapa plinian pumice-fall deposit 20,000 years ago.
20,000 years ago.