A quarry wall on the lower NW flank of Cofre de Perote volcano exposes a cross-section through part of the Xáltipan Ignimbrite, which erupted about 460,000 years ago and resulted in the formation of Los Humeros caldera. This massive 230 km³ ignimbrite covers a 3,500 km² area and extends at least 50 km to the coastal plain. The mostly non-welded rhyolitic ignimbrite is overlain by co-ignimbrite airfall tuffs and eight airfall lapilli tuffs.

Photo by Lee Siebert, 1997 (Smithsonian Institution).

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

Keywords: stratigraphy | geology | ignimbrite | outcrop

Los Humeros