FRACTURE ANALYSIS OF A FAULT-PROPAGATION FOLD RESTING IN THE FOOTWALL OF THE BELLUNO THRUST, NORTHEAST ITALY

Abstract

The Belluno Syncline, resting in the footwall of the Belluno Thrust, is located in the Venetian fold and thrust belt, in the Italian Southern Alps. This SSE-vergent mountain chain developed mainly during the Neogene as a back-thrust belt of the Alps in response to deformati on of the northern margin of the Adria pi ate. The Belluno syncline is asymmetòc in shape, with a steep bac­klimb, as the forelimb of the paired Monte Coppo lo Anticline, and results from fault-propagation folding during the development of the underlying Belluno thrust. In plan view, the Belluno thrust shows a prominent curvature interpreted as reactivation of inherit­ed Mesozoic extensional structures. The hinge of the Belluno syncline presents a similar curvature. Rocks outcropping in the syncline core are Upper Chattian to Langhian fine-grained molas­sic sediments, mainly siltstones and marls. [...]