Seasonal dynamic of weathering processes in badlands of the Central Spanish Pyrenees

Abstract

Badland morphologies are one of the most characteristic elements, due to abundance and hydro-sedimentological impact, in the Central Pyrenees. The genesis and development of badlands is favoured by bedrock lithology, topography and climate. The main purpose of this paper is to study geomorphological dynamics of these badlands and, particularly, the temporal and spatial relationships of the weathering processes. The study, performed in a small mountain catchment (45 ha) with a dense network of badlands (9 ha), is focused in the election and control of some physical variables that allow the temporal comparison of surface regolith development and that can be considered as weathering indicators of the marls. The results validate the methodology in use, favouring processes description, their chronological sequence and their relationship with climatic and topographic parameters. The development and dynamics of regolith on the north-facing slope is more active than on the south-facing slope. On the north-facing slope freezethawing are the main weathering processes, while on the south-facing slope prevails the crusting development associated to wetting-drying processes. On the other hand, the dissolution of carbonates is higher in the north exposition, and especially on the upper layers of the regolith, because to the washing effects and minor temperatures.