Global Volcanism Program | Image GVP-03932
This roadcut provides a spectacular section through a debris avalanche deposit hummock of the Fuego-Acatenango complex in Guatemala. The pronounced color mottling is a common texture of debris-avalanche deposits and distinguishes them from deposits produced by other volcanic processes such as mudflows or pyroclastic flows. This texture results from the transport of coherent chunks of the volcano over long distances with only partial disaggregation. Individual lava flow blocks and pyroclastic units can be traced across small offsetting faults.
Photo by Lee Siebert, 1988 (Smithsonian Institution).