Relationships amongclimate, uplift and palaeo-landslides generation in the Melandro River basin, southern Apennines, Italy

Abstract

The Melandro River valley is a tectonically controlled and uplifted basin located in the Italian southern Apennines. The goal of this paper is to point out ages and geomorphic features of two palaeo-landslides and to relate them with uplift rates and climate conditions of the axial zone of the chain during the Pleistocene. Uplift rates have been estimated using geomorphic data related to erosional gently dipping land surfaces. Landscape development has been driven by an alternation of stages of uplift and slack periods. Stability of base level of the erosion favoured the planation of land surfaces whereas unsteady base level resulted in widespread reduction of erosional flatlands. The oldest palaeosurface cuts Pliocene deposits at the tops of the mountains whereas the youngest surface is late Pleistocene in age. In the southern area of the basin a wide palaeo-landslide, whose foot is cut by a fragment of the middle Pleistocene land surface, forms a morphological high separating different sectors of the basin in which lower Pleistocene sediments were confined. The landslide can be therefore ascribed to the upper part of the early Pleistocene. Another palaeo-landslide, recognized in the northern sector of the basin, can be referred to the beginning of the late Pleistocene. The correlation between the ages of the two landslides and the temporal trend of the uplift rates allowed to hypothesize that mass movements occurred in response to uplift peaks, when slopes were destabilized by rapid relief growth, and after stages of deep weathering probably caused by warm-humid climate.