The Acatlán Ignimbrite covers 150 km². It is compositionally zoned, grading from a white-or-pink colored basal rhyolitic tuff to a black upper andesitic tuff. The upper andesitic tuff is welded in the western part of the deposit, with the degree of welding increasing towards the top.

Photo by Jim Luhr, 1983 (Smithsonian Institution).

This image is made available under the Public Domain Dedication CC0 license, but proper attribution is appreciated.

Acatlán Volcanic Field