Estudio granulométrico y componentes juveniles de los depósitos de lahares primarios en el flanco N del volcán Cotopaxi: trabajo de integración curricular presentado como requisito para la obtención del título de Ingeniera en Geología.

Abstract

Cotopaxi is characterized as one of the most dangerous volcanoes in Ecuador due to its eruptive history, which is currently in a new eruptive phase with the emission of ash and gases. It is known that its last major eruptive event was on June 26, 1877, which, as a result, presented ash rain, pyroclastic flows, and lahars, whose deposits are in the drainage of the N flank of the volcano. The present study work focuses on the characterization of these primary lahar deposits. The methodology used is based on the granulometric study and analysis of juvenile components. Granulometric analysis shows that the deposit is classified as a non-cohesive debris flow, which implies a very bad draw in its sediments. In the analysis of juvenile components, the percentages observed were from 23 to 48% in a fraction of 500-1000um. Juvenile fragments were defined from a pyroclastic flow sample corresponding to the same eruption. Also, an increasing trend of juvenile components is observed that goes from N to NE of the flank of the volcano within the lahar deposits. With the results obtained, they contribute to an advance in the characterization of the lahar compared to previous studies. In addition, they would help with the more specific characterization of the lahar and modeling of future lahars.