Post-rift Aptian-Cenomanian extension in Adria, insight from the km-scale Positano-Vico Equense syn-sedimentary fault

摘要

? 2023 Elsevier LtdDuring the late Early Cretaceous, at the beginning of the Africa-Europe convergence, some portions of Adria experienced an enigmatic post-rift subsidence acceleration. According to many, this event is likely associated with extensional tectonics, which, however, hardly fits the Aptian-Cenomanian convergent framework of the central Mediterranean area and suffers from the apparent lack of coeval faults unquestionably linked to crustal stretching. Here we reconcile the tectonic and geodynamic records of Adria by introducing a syn-sedimentary extensional fault system exposed in the Lattari Mts. (southern Italy), currently forming the largest exposed Aptian-Cenomanian extensional system of Adria. Our structural reconstruction shows that the extensional displacement of the main fault is 2 km, at least 0.7 km of which was acquired during the Cretaceous. Radiometric dating indicates that reactivation and further growth of the fault occurred at 12.8 ± 0.5 Ma and 5.8 ± 3.4 Ma. To explain extensional tectonics in the framework of Africa-Europe convergence, we propose a slab pull mechanism, in which the traction exerted by the subducting Neotethys Ocean was responsible for the stretching of continental ribbons of Adria.