Global Volcanism Program | Image GVP-07843
Thick units of the 84,000-year-old Los Chocoyos Ash are exposed south of Guatemala City, more than 100 km from its source at Atitlán caldera. Three flow units are visible here. The pinkish layer at the center of the outcrop is the oxidized top of the pyroclastic-flow deposit and is one cooling unit. The bottom two layers are the top and bottom halves of the thick white layer of the pyroclastic-flow deposit. The two fall deposits above the Los Chocoyos Ash are unit E from Amatitlán caldera and the younger unit C from Agua volcano.
Photo by Bill Rose, 1978 (Michigan Technological University).