Large-scale collapse of the Pacaya summit sometime between about 1,550 and 600 years ago created a large horseshoe-shaped scarp. Collapse was followed by a large explosive eruption that produced widespread pyroclastic surges. This roughly 150-m-high section of the NW scarp exposes light-colored lava flows overlying pyroclastic deposits of the pre-collapse edifice. Subsequent eruptions have constructed a new cone within the caldera. Lava flows from MacKenney cone (out of view to the right) are slowly filling in the caldera moat.

Photo by Lee Siebert, 1988 (Smithsonian Institution).

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

Keywords: landslide scarp | outcrop | stratigraphy | geology

Pacaya