limestone
basalts
  Pescados debris flow
    Vol.: 4 km 3
Distance: + 85 km
Pescados debris flow
40 ky
Los Pescados deposit consists of at least two different units that crop out along Los Pescados river valley forming a central terrace slightly dipping to the east. The deposit forms the lowermost channel-filling terrace deposit of Los Pescados River, and is therefore the youngest deposit in the area. It overlies a basaltic lava plateau, which has been dated at 0.26 +/- 0.03 Ma by the 40Ar/39Ar method.
Some blocks show jigsaw-fractures typical of debris avalanches, but there are no hummocks at the surface of this deposit. This deposit may have been originated from a catastrophic edifice collapse and rapidly transformed to a lahar that flowed to a distance of at least 50 km from the Cofre de Perote source.