Control estructural en la generación de remociones en masa en el sector de Curarrehue en los Andes del Sur, Región de La Araucanía
Control estructural en la generación de remociones en masa en el sector de Curarrehue en los Andes del Sur, Región de La Araucanía
Authors
Prieto Santibáñez, Esteban
Authors
Date
2022
Datos de publicación:
Keywords
Litología - Geología - Mineralogía - Arcilla - Remociones en masa - Fallas activas - Hidrotermal - Salbanda - Deformation - Active faults - Faults - Lithology - Landslides - Hydrothermal - Stress - Clay - Gouge - Rainfall
Collections
Abstract
El presente trabajo se desarrolló en la comuna de Curarrehue, Región de la Araucanía, en donde se analizaron los procesos de remociones en masa del sector buscando dar una posible respuesta a los mecanismos de control y propagación de estos. Se analizó el vínculo y relación que existe entre las remociones en masa, la litología y las fallas activas del intra arco en el sector, realizando un mapeo y reclasificación de las remociones trabajadas, en conjunto con un análisis de la cinemática de las fallas activas dentro del área de estudio para obtener los campos de deformación y estrés que las gobiernan, en donde los resultados nos señalan que todas las remociones en masa del sector están relacionadas a fallas activas, las cuales además se intersectan dentro del sector estudiado, sugiriendo puntos de debilitad estructural. El control litológico fue enfocado en el análisis de la mineralogía hidrotermal y la mineralogía arcillosa en la salbanda de los planos de fallas activas asociados a las remociones seleccionadas, evidenciando una asociación hidrotermal Chl + Ep ± Cc ± Alb ± Ser y mineralogía arcillosa, la cual es importante de considerar debido a las variaciones de presión de los fluidos producto de las propiedades expansivas de las arcillas ante eventos de lluvias, particularmente considerable en eventos de lluvias extremas. Los resultados permitieron finalmente sugerir una relación entre el control litológico y estructural con el desarrollo y propagación de remociones en masa en el área de estudio, condicionado principalmente por las fallas activas, el grado de alteración y el contenido arcilloso del macizo rocoso.
The present work was developed in the commune of Curarrehue, Araucania Region, where the processes of landslides in the sector were analyzed looking for a possible answer to the control mechanism and propagation of those processes. We analyzed the link and relationship between the landslides, the lithology and the intra-arc active faults in the study area, making a mapping and reclassification of the landslides worked, in conjunction with an analysis of the kinematics of the active faults within the study area to obtain the deformation and stress fields that govern them, where the results indicate that all landslides in the area are related to active faults, which also are intersected within the studied location, suggesting structural weakness points. The lithological control was focused on the analysis of the hydrothermal mineralogy and clay mineralogy in the gouge of the active fault planes associated to the selected landslides, evidencing a hydrothermal association Chl + Ep ± Cc ± Alb ± Ser and clay mineralogy, which is important to consider due to the variations in fluid pressure resulting from the expansive properties of the clays in rainfall events, particularly considerable in extreme rainfall events. The results finally allowed to suggested a relationship between lithological and structural control with the development and propagation of landslides in the study area, mainly conditioned by active faults, the degree of alteration and the clay content of the rock mass. The results suggested a relationship between the lithological and structural control with the development and propagation of landslides in the study area, mainly conditioned by active faults, the degree of alteration and the clay content of the rock massif.
The present work was developed in the commune of Curarrehue, Araucania Region, where the processes of landslides in the sector were analyzed looking for a possible answer to the control mechanism and propagation of those processes. We analyzed the link and relationship between the landslides, the lithology and the intra-arc active faults in the study area, making a mapping and reclassification of the landslides worked, in conjunction with an analysis of the kinematics of the active faults within the study area to obtain the deformation and stress fields that govern them, where the results indicate that all landslides in the area are related to active faults, which also are intersected within the studied location, suggesting structural weakness points. The lithological control was focused on the analysis of the hydrothermal mineralogy and clay mineralogy in the gouge of the active fault planes associated to the selected landslides, evidencing a hydrothermal association Chl + Ep ± Cc ± Alb ± Ser and clay mineralogy, which is important to consider due to the variations in fluid pressure resulting from the expansive properties of the clays in rainfall events, particularly considerable in extreme rainfall events. The results finally allowed to suggested a relationship between lithological and structural control with the development and propagation of landslides in the study area, mainly conditioned by active faults, the degree of alteration and the clay content of the rock mass. The results suggested a relationship between the lithological and structural control with the development and propagation of landslides in the study area, mainly conditioned by active faults, the degree of alteration and the clay content of the rock massif.
Description
Trabajo financiado bajo el Proyecto FONDECYT 3200387
Trabajo de título para optar al título de Geólogo
Trabajo de título para optar al título de Geólogo