Abstract

The mountainous block of the south edge of the river basin of the Maipo river is analyzed that is part of the coastal range, separated of the andean block by the narrow valley of the Angostura river. It corresponds to a sector of media and low mountain of igneus and folded cretacic rocks. Although the seasonal nival effect is made feel in summits of the order of the 2,000 m.s.n.m., predominates the mountain environment with soils and vegetation. It was considered to analyze the slopes geodynamics in the consideration of his structural character. Two systems are analyzed, the one of Aculeo and the Poca Pena mountain, that has been classified like a residual erosion surface. The modern geodynamics has been analyzed according to the deposits of cone and glacís, its state and present operation. The more dynamic process corresponds to seasonal debris flows.