Global Volcanism Program | Image GVP-07857
A geologist photographs an outcrop of the 84,000-year-old Los Chocoyos Ash near Patzún, about 10 km east of Lake Atitlán. Note the charred log above the photographer. This pyroclastic-flow member of the Los Chocoyos is up to 200 m thick and is exposed over an area of about 2000 sq km. Individual flow units of the voluminous 275 cu km ignimbrite are sometimes more than 100 m thick. The upper part of the deposit is characteristically salmon-pink in color as a result of oxidation of the cooling flow.
Photo by Bill Rose, 1980 (Michigan Technological University).