LA TETTONICA TRASVERSALE DELL'APPENNINO SETTENTRIONALE: IL CASO DELLA VAL MARECCHIA

Abstract

Structural, geological, sedimentological and geophysi­cal data support the existence of transversal tectonics in the Val Marecchia area. Such tectonics is related to the migra­tion of the deformational front and is expressed by dynamic and mobile activity. Until the Tortonian phase, the migra­tion of the foredeep-thrust belt front regularly occurred in­volving turbiditic closure pelites and transversely delimiting them by the tectonic lineament Arezzo-Badia Tedalda. Af­terwards, the counter-clockwise rotation of the Italian penin­sula leads, since Lower Messinian, to the formation of tec­tonic arcs. Among these arcs, the Romagnan and Adriatic ones come to separate in correspondence with the Val Marec­chia tectonic lineament via the formation of a depressed area bending inside of the Apenninic chain. Transversal tectonics is then related to different rates of migration of the defor­mational front, which in turn is probably linked to discon­tinuities and/or heterogeneities of the underlying basement.