MASS MOVEMENTS RELATED TO TECTONICS IN THE ASPROMONTE MASSIF (SOUTHERN ITALY)

Geomorphic and structural studies have been carried out on the headwat ers of Vallone Colella Torrent, in an area intensely affected by mass- movement phenomena on the Aspromonte massif of southern Italy. Rock ty pes outcropping in the area are mostly gneiss and granitoids, with sub ordinate presence of metarenites, phyllites, and biotite schists; all lithologies experienced low-grade metamorphism, as indicated by petrog raphic analysis. Structural surveys, performed at macroscopic and meso scopic scale, allowed recognition of several sets of discontinuities r elated to different deformation events. The upper reaches of Vallone C olella Torrent present a large, active landslide zone, the debris mate rials of which feed the debris flows along the drainage system towards the main valley. Mass-movement phenomena are both shallow and deep-se ated; the latter are limited to a sector of the study area, while shal low processes are present throughout the landslide zone. Some consider ations of the relationship between tectonics and mass movement are pre sented, with particular reference to the presence of a large-scale dow nthrown wedge (bounded by structural surfaces on both sides of the val ley), located in the same area affected by deep-seated phenomena.