Particolari forme di deposito glaciale nell’area terminale del Ghiacciaio del Pisgana (Alpi Retiche, Gruppo dell’Adamello)

Particular landforms of glacial deposition on the terminal area of the Pisgana Glacier (Rhaetian Alps, Adamello Group)

Abstract

The author describes some landforms of glacial deposition he observed on the terminal area of the Pisgana Glacier in the Adamello Group. In the glacial drifts two different kinds of landforms can be seen: cone forms and ridge forms, which can be found both crosswise and lenghtwise on the tongue of the glacier. After describing their main morphological features, the author faces the problem of their origin. He thinks that these glacial drifts can be produced by the filling of a network of crevasses and by a selective ablation. As to the denomination, the author thinks that the terms esker and osar previously used for the landforms of the Pisgana Glacier, aren’t the proper words. In fact they point out the last stage of a morphological process of which the described landforms can be the earlier stage only. He suggested the terms complex of ridges and ice cones drifts.