Tectonically- and gravity-driven faults in the slope to basinal carbonates of Gargano Promontory, Italy

Carbonate platforms’ slopes are generally characterized by coarse-grained, mass-flow deposits forming major hydrocarbon reservoirs. As a consequence, a good understanding of their depositional and structural architectures is key to better produce from these deposits. The platform margin and associated slope deposits of the Apulian carbonates nicely crop out in the Gargano Promontory, Southern Italy. There, these carbonates show the results of several depositional, gravitational and syn-sedimentary tectonic processes, which, in turn, may have controlled the evolution, and its subsequent deformation, of the ancient slope. Both syn-sedimentary tectonic and gravity-driven faults, as well as post-sedimentary ones, are present along the coastal outcrops displayed from Mattinata to Vieste. Syn-sedimentary normal faults can be recognized based upon several features displayed in the field, such as bed thickness variation across them, synfaulting rotation of bed-parallel stylolites and plastic deformationof chert layers. We associate the syn-sedimentary faults to the gravitational processes, such as slumps and debris flow, widely documented in literature within the Lower Cretaceous Mattinata and Maiolica Formations. The attitude measured along the synsedimentary faults is consistent with a NE-SW oriented platform margin in the southern part of the study area (from Mattinata to Testa del Gargano) and a NW-SE oriented margin in the northern part (from Testa del Gargano to Vieste). Moreover, tectonicdriven, syn-sedimentary low- and high-angle normal faults are also present in the study area, which crosscut debris flow and slumps sediments and are usually characterized by segmented fault plane, not well-developed or just tip damage zone and displacement from several centimeters to meter. Gravitycontrolled faults have typically no fault core, displacement of centimeters to tens of centimeters and fault plane with changing inclination up to bed-parallel orientation. Distinguishing between syn-sedimentary faults tectonic and gravity-driven faults in the slope-to-basin carbonates of the Apulian platform and their relationship with the orientation of the paleo-margin, we aim at improving the prediction of both type and distribution of the deposit hosting hydrocarbon reservoirs.