Caracterización geotécnica de las rocas volcánicas involucradas en la avalancha rocosa de Arteara (Gran Canaria, Islas Canarias)

Abstract

The Arteara rock avalanche was developed in the Fataga Group, which is related to the first volcanic stage in the Gran Canaria Island (8.6-13.3 Ma). The materials of the avalanche are mainly phonolitic ignimbrites and lava flows. We studied the geotechnical quality of the five lithotypes distinguished in the area: phonolitic lava, phonolitic agglomerate breccia, reddish non-welded ignimbrite, welded fiamme-bearing ignimbrite, and pumice tuff with lithics. The weak geotechnical parameters of the reddish non-welded ignimbrite, the pumice tuff with lithics and the agglomerate breccia, and their location at the middle of the slope, suggest that these three lithotypes can be regarded as potential sliding surfaces of the block which triggered the avalanche. The geomechanical parameters of the volcanic rocks found in this study are very useful for future studies concerning the modelling of the mechanism of failure and run out of the Arteara rock avalanche.