Características geológicas y morfologías singulares de la región del Alto Asón (Cantabria)

Resumen

Geological features and glacial and karst morphology in the Upper Asón region in the eastern Cantabrian Mountains are described. The Cretaceous materials were a'ected by the Alpine orogeny, which formed a slightly inclined monocline. They are characterised by an alternating sequence of detrital materials and reef limestones, known as the Urgonian complex. The alternating distribution of materials, together with the faulting in the area, has allowed the development of surface and subterranean karst morphology to form a genuine underground paradise. Glacial morphologies are well preserved and acquired considerable importance owing to the size of the icecap and its low altitude; till deposits are found at 350m above sea level, the lowest altitude in the Iberian Peninsula. The formation and later development of the &uvial network has been conditioned by cortical movements and the structure and lithology of the bedrock, resulting in sudden changes in the direction of the River Asón and the landforms associated with it (gorges, rock falls, scree slopes, etc.)