TTE148

Control estructural en la generación de caída de rocas…

ABSTRACT

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.

Key words: Landslides, lithology, faults, active faults, deformation, stress, hydrothermal,

gouge, clay, rainfall.

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