Slope dynamics in the central sector of Asturias (Villoria river-basin, Cantabrian Cordillera)

Abstract

The Quaternary evolution of the Villoria River Basin has been conditioned by fluvial and slope instability processes. The deposits linked to the later one are the more extensive in the area. The Instability types depend on litology, vegetation and climatic factors. Slope instability in calcareous cliffs in the South is due to rockfall and rock-avalanches processes. Carboniferous sandstone and siltstone alternations appearing in the rest of the area, show mass movements development and active creep evidences where there is an important vegetation cover. Not forested areas show rills as result of soil erosion. Mass movement types are varying from mudflows to debris-flows, with deposits that show the alternating action of both processes through the time. Rainfall is a triggering factor as shown by the development of instabilities during maximum rainfall events. One of these depositis has been dated by 14C method at 2.010 + - 70 BP.