Il glacialismo “locale” Würmiano del massiccio del Grappa (provincie di Treviso e di Vicenza)

“Local” Würmian glaciation of the Grappa Massif (Provinces of Treviso and Vicenza)

Abstract

A map showing the distribution of glacial phenomena on the Massif, spatially unconnected with the general “Alpine” glaciation is presented. The modelling forms consist of cirques, “embryonic cirques”, and nivation hollow of various sizes and facing different directions. These are variously connected to deposits and their morphological expression. There are three clearly-defined major units, corresponding to three glacial bodies: the largest is on the Northern slope of the massif (Val delle Bocchette, Val dei Lebi, Val dei Pes); the intermediate is on the Western slope (Valli del Busetto, Val del Termine, Val Cesilla); the smallest is on the South-Western slope (Val delle Foglie). Alongside these three units, minor glacial traces have been recognised in Val di Poìse and Val delle Mure. Further down, the deposits and glacial forms appear to have been dissected by Post-glacial and Holocene strong erosive activity, which incidentally has brought about an array of impressive river captures, connected with the recent, powerful tectonic uplifting of the massif at the pre-Alps flexure that forms its SW boundary. The morphological and pedological features of these glacial remains indicate that they should be assigned to the maximum expansion phase (W3) of the last glaciation. Lastly, it is suggested that the pronounced swelling the glacial bodies must have displayed must be related to the relatively low permanent snowline, this in turn being associated with the specific orographic feature of the massif.