Physical weathering and regolith behaviour in a high erosion rate badland area at the Pyrenees: research design and first results

Abstract

The present work was started to characterize the physical weathering processes and rates in relationship with thermic and moisture conditions in the Vallcebre Basin, High Llobregat. The method used consists of the continuous monitoring of regolith temperatures at different conditions of aspect, depth and lithology (colour), and the periodical sampling of regolith moisture and bulk density, the last taken as an indicator of the weathering status. The changes of the surface of the regolith have been monitored with the help of photographic techniques. A laboratory experiment was also performed on undisturbed rock samples. The results obtained emphasize the role of frost action, especially during wet conditions. Aspect and lithologic differences introduce significant nuances in thermic regime and volumetric changes respectively. -from Authors