RICERCHE GEOLOGICHE SUL MESOZOICO DEL GRAN SASSO D'ITALIA (ABRUZZO). II. EVOLUZIONE TETTONICO-SEDIMENTARIA DAL TRIAS SUPERIORE AL CRETACEO INFERIORE DELL'AREA COMPRESA TRA IL CORNO GRANDE E S. STEFANO DI SESSANIO (F. 140 TERAMO)

Abstract

The sedimentary-tectonic evolution embracing the Upper Triassic-Lower Cretaceous of the western section of the Gran Sasso d'Italia (F. 140 Teramo of the Italian Geologica! Map) is described. The investigation is based onfacies analysis and the study of severa! stratigraphic sections. The first important event, i.e. the fragmentation of the Triassic-Liassic carbonate platform, occurred at the end of the Lo­wer Lias. It was related to intense distensive tectonics which altered the previous paleogeographic picture. This led to the formation of a marginai carbonate platform environment located in the southea­stern portion of the area under study. In additiqn a widespread pe­lagic environment prevailed in the north-central portion. Both envi­ronments were maintained throughout the period being considered. [...]