Upper Permian Evaporites of Dolomite Mountains, Northern Italy: ABSTRACT

Abstract

The Bellerophon Formation (Upper Permian) of the Dolomite Mountains in Italy is composed of evaporite and carbonate facies. The former are both supratidal (sabkha) and shallow subaqueous in origin. The latter consists of limestone, evaporitic dolomites, and dolomitic arenites. The rocks are underlain by continental clastics of fluvial and overbank facies and are overlain by a predominantly open-marine, shallow-water carbonate sequence. The facies reflect climatic variation, sea-level fluctuation, and changing sedimentologic conditions. This area has undergone postdepositional tectonic deformation. The deformation is, in part, recorded in a variety of structures in the Bellerophon Formation. Tectonic stylolites, as a response to stress, are widespread in the carbonate facies. In the evaporite facies, deformational fabrics are more varied. Flow structures and mylonitic textures clearly reflect bedding-parallel shear, whereas in the layered dolomite-evaporite parts of the sequence folding is a more common response to tectonic deformation. Recognition of the extent and nature of these varied structures provides a greater understanding of the geologic history of this and adjacent regions. The deformation seen in the evaporites may provide clues to an understanding of fluid migration in other tectonically stressed areas in which evaporites are found. End_of_Article - Last_Page 628------------