On the axial zone of the Southern Apennines the major tectonic boundary between the inner platform (Western platform unit) and the pelagic (Lagonegro units) domains is represented by a thick level of highly deformed rock-assemblage. Structural analysis reveals that this tectonic unit represents an intracontinental melange complex characterized by a block-in-matrix fabric that contains blocks from both hangingwall platform and footwall basin units. This unit comprises different sets of structures that, caused by shearing processes, developed at depths ranging from about 8–9 km to the surface. These tectonites represent the product of a crustal shear zone developed at the major boundary between platform-basin domains of Adria during the thick-skinned tectonic processes controlling the Southern Apennines mountain building.