Le Permien Des Prealpes Lombardes Orientales

Abstract

On the basis of new geological and petrographical researches throughout the Palaeozoic cover between the Trompia Valley and Croce Domini Pass, the authors summarize the characteristics of the lithostratigraphical units. These are from bottom to top: “Basal Conglomerate”, “lower quartz-porphyries”, Collio Formation with some rhyolitic lavas interstratified, Dosso dei Galli Conglomerate, Auccia Volcanites and M. Mignòlo Sandstone (Lombardy Verrucano).

The succession above described is typical of eastern Lombardy, where it is chiefly noted for the fossils found in the Collio, including vegetables and vertebrate footprints from the Rotliegende.

This is followed by a synthesis concerning the principal stra tigraphical characteristics westwards, in the Camonica Valley, and eastwards, in the Caffaro Valley.

The investigations on the geographical limits and the frequent stratigraphical variations of the Collio basin has made it necessary to provide a general description of the Permian in the neighbouring localities. These are present in the western region of the Chiese and between this river and the Rendena Valley.

A chronostratigraphical classification of the Lombardy formations has been attempted on the basis of the recent palaeontological examinations of some German specialists (H. Haubold, W. Remy). We have also described briefly the principal events in the whole Collio basin.

L’étude sur le terrain a été effectuée par G. Cassinis grâce à l’aide financière du Conseil National des Recherches. En ce qui concerne la rédaction de la présente étude, G. Cassinis est responsable des observations de caractère litho- et chronostratigraphique et paléogéographique; quant aux données pétrographiques sur les roches volcaniques, nous les devons à Madame G.Peyronel-Pagliani