Rovine of Bletterbach / Rio delle Foglie – Val Gardena Sandstones

Stream erosion in rocky formations by Rio delle Foglie/Bletterbach has generated a deep, locally meandering gorge, arranged approximately E-W. The width of the gorge varies from 20-30 metres in the volcanic rock (ignimbrite) at the basis of the stratigraphic series to 200-300 m at the roof. The riverbed is interrupted in at least four places by waterfalls tens of metres high. In its terminal part the gorge opens up into a basin 600-700 m in diameter, where it is possible to admire the spectacular multi-colour series of the Bellerophon and Werfen Formations, with prevailing light-coloured dolostone at the roof of Corno Bianco/Weisshorn. The area around Rio delle Foglie – Bletterbach Gorge is mainly characterised by glacial deposits and landslide bodies of large dolostone blocks ascribable to glacial transportation. From a morphotectonic viewpoint, there is no evidence of recent activity which might have caused particular landforms. Very likely, the deep cut of the Torrent Bletterbach is located in correspondence with a fracture which, in any case, does not displace the rock. From a morphoselective viewpoint, some small steps are formed in the fairly erodible rock types of the Valgardena Sandstone, Bellerophon and Werfen formations. A spectacular waterfall can be admired in correspondence with a bed made up of Valgardena Sandstones (with cephalopods). From a morphoclimatic viewpoint, the top area shows some remnants of glacial deposits, probably ascribable to the LGM. Some accumulations of large, allochthonous dolostone blocks are also found; they are related to mass movements with probable glacial transportation or reworking. An extrinsic morphological geodiversity of this small system is offered by a characteristic gorge, 8 km long and 400 m deep, dug into steep walls and at places interrupted by morphostructural steps and water falls.