A geologist examines an outcrop of the 84,000-year-old Los Chocoyos Ash near Patzún, about 10 km E of Lake Atitlán. Note the charred log above his head. This pyroclastic flow unit of the Los Chocoyos deposit is up to 200 m thick and is exposed over an area of about 2,000 km². Individual flow units of the voluminous 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).

This image is made available under the Creative Commons BY-NC-ND 4.0 license terms.

Keywords: stratigraphy | geology | tephra | ignimbrite | stratigraphy | field work | outcrop | oxidation | volcanologist

Atitlán