Transverse versus longitudinal extension in the foredeep-peripheral bulge system: Role of Cretaceous structural inheritances during early Miocene extensional faulting in inner central Apennines belt

Abstract

This study reports on the Rocca di Cave extensional fault system, which is located in the Prenestini Mountains (Central Italy) of the Apennines fold-and-thrust belt and presently represents the oldest exposure of early orogenic foreland fault system of the Apennines. This fault system was oriented perpendicular to the strike of the foredeep-peripheral bulge system, indicating that the onset of convergence was marked by a foredeep-parallel extension, instead of the commonly observed foredeep-perpendicular stretching associated with lithosphere flexuring. The studied fault system is formed by a 10 km long and 2 km wide E-W elongated area that includes two mutually orthogonal sets of faults oriented about E-W and N-S, respectively. E-W and, mainly, N-S striking faults developed during a preorogenic (Santonian to Campanian in age) E-W oriented extension kinematics, which caused first uplift and erosion and then drowning of the Cretaceous carbonate platform and the onset of a pelagic environment. Both fault sets were later reactivated in the early Miocene, when the area was forming part of the foreland region ahead of the eastward migrating Apennines fold-and-thrust belt and was undergoing local N-S oriented, i.e., foredeep-parallel, stretching. This extensional stage implied the sedimentation of hundreds of meters of synkinematic strata in the northern block of the Rocca di Cave Fault System, coevally with episodes of subaerial erosion in areas of the southern block. Further extensional and right-lateral reactivation of inherited faults occurred in the late Miocene, during the progressive incorporation of the area into the Apennines belt.

Structural, stratigraphic, and petrological clues for a Cretaceous–Paleogene abortive rift in the southern Adria domain (southern Apennines, Italy)

“…In detail, extension and crustal thinning impose the asthenospheric rise, which produces the bulging of the overlying lithosphere (e.g., Van Wees & Cloetingh, ) and a partial dismembering of the platform domains. Such an inference about the asthenosphere rise is fully supported by the evidence that Late Cretaceous extensional faulting was coeval with uplift and erosion (e.g., Shiner et al, ; Tavani et al, ). At the end of Cretaceous, the complete drowning of some sectors of the Adria–Hyblean domain (especially those of the Sicilian sector; Figure b) and the uplift of the eastern rift flank (most of the sectors of the Apulian and Apennine platforms) were almost completely achieved.…”

“…This third episode fits well with data from the Sabini Mts., close to the city of Rome. There, uplift, differential erosion, and subsequent drowning of this sector of Lazio–Abruzzo platform were caused by Santonian–Campanian movements of kilometer‐sized faults (Tavani et al, ).…”

“…During the Late Cretaceous-Eocene period, scattered manifestations of an anorogenic magmatism affected the Apennine-Apulian margin basin, the Sicilian Maghrebian platform basin, the Ligurian successions, and the Sicilian foreland (Lucido, Nuccio, Valenza, & Giunta, 1978;Bellia, Lucido, Nuccio, & Valenza, 1981;Di Girolamo, Morra, & Perrone, 1992;Di Girolamo, Morra, & Galdi, 1994;Bigazzi, Laurenzi, Principe, & Brocchini, 1996;Grasso, Pezzino, Reuther, Lanza, & Miletto, 1991;Groppelli & Pasquarè, 2004;Beccaluva et al, 2007;Bianchini, Beccaluva, & Siena, 2008;Avanzinelli, Sapienza, & Conticelli, 2012;Stoppa, Rukhlov, Bell, Schiazza, & Vichi, 2014). In addition, deformation structures related with an Albian-Late Cretaceous extension episode were described in the Apulian domain (e.g., Chilovi, De Feyter, & Pompucci, 2000;Festa, 2003;Korneva et al, 2014;Masse & Borgomano, 1987;and references therein) and in the southern (Carannante et al, 2009;Tavani et al, 2013) and central Apennines (Bigi & Costa Pisani, 2005;Capotorti, Fumanti, & Mariotti, 1997;Tavani, Vignaroli, & Parente, 2015).…”

Late Oligocene to Pliocene Extension in the Maltese Islands and Implications for Geodynamics of the Pantelleria Rift and Pelagian Platform

“…Pedley and Grasso () describe the presence of N‐S trending structures in the NW part of the Hyblean platform (NW Sicily) that should have been active in this period. Tavani, Vignaroli, and Parente () found evidences of an Early Burdigalian extension in the Penestrini Mountains (Central Apennines) followed by a tectonic quiescence up to the Tortonian. Belguith et al () have documented a minor Lower‐Middle Miocene extension in onshore Tunisia.…”

“…Fold and thrust belts developed along subduction zones are characterized by complex deformation patterns and their influence is felt in foreland areas well ahead the trench and/or the front of contractional tectonics. Flexure of the foreland due to the load imposed by the advancing convergent margin results in extensional tectonics, which can be interpreted also as the effect of slab pull (Bradley & Kidd, ; Doglioni, ; Forsyth & Uyeda, ; Langhi et al, ; Tavani, Storti, et al, ; Tavani, Vignaroli, & Parente, ; Tavani et al, ; Turcotte & Schubert, ). Hence, forelands are characterized by extensional faults, veins, and joints parallel to the trench axis (Beaudoin et al, ; Billi & Salvini, ; Mazzoli et al, ; Quintà & Tavani, ; Ranero et al, ; Scisciani et al, ; Tavani et al, ; Tavani, Storti, et al, ; Tavani, Vignaroli, & Parente, ) and from structures perpendicular to the fold and thrust belt, like cross joints and release faults (Bai et al, ; Gross, ; Tavani et al, ).…”