Volume 4 Quaternary Chapter 8 Neogene https://doi.org/10.32685/pub.esp.38.2019.08 Holocene Lahar Deposits Associated with the Published online 27 November 2020 Eruptive Activity of Cerro Machín Volcano, Colombia: Impact on Landscape and Associated Paleogene Potential Hazards 1
[email protected] Gloria Patricia CORTÉS–JIMÉNEZ1* Servicio Geológico Colombiano Cretaceous Dirección de Geoamenazas Abstract Cerro Machín Volcano is an active volcano (4° 29’ N; 75° 23’ W) located in the Avenida 12 de octubre n.° 15–47 Manizales, Colombia central part of the Colombian Andes (Tolima Department, Colombia). Lahars are one * Corresponding author of the greatest hazards associated with Cerro Machín Volcano. Approximately 300 000 people live in lowlands around the volcano. This added to the explosive potential, Jurassic chemical composition, magnitude of its eruptions, and distribution of its deposits make Cerro Machín one of the most dangerous volcanoes in Colombia. Volcanic risk management of Cerro Machín requires a balance of science, education, risk reduction, and disaster management, which are all critical to the safety, well–being, and quality Triassic of life of the population living around the volcano. The highly explosive eruptions that have occurred in the last 10 000 years have generated thick sequences of pyroclastic fall and pyroclastic density current deposits, which have filled the valleys of rivers and streams within a 15 km radius of the volcano. The interaction of pyroclastic material with water generates large lahars that flow for Permian distances greater than 100 km along the Coello and Magdalena Rivers channels. The distribution and total extension of the lahar deposits allow us to identify three depo- sition areas: proximal, intermediate, and distal.