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The paper deals with original stratigraphic, petrographic and structural data concerning the evolution of the southern Apennines chain (Italy). The main Langhian to Pliocene deposits cropping out in the northern sector of the southern Apennines foreland basin system (Sannio-Irpinia area) have been studied and correlated in order to document the effects of tectonic changes on the evolution of sandstone detrital modes and stratigraphic architecture. The studied sandstone units can be grouped in five key intervals: a) Numidian Flysch, mostly formed by Langhian mature quartzarenitic deposits and conformable Serravallian post-Numidian successions, formed by arkosic and calciclastic arenaceous-pelitic beds (foreland depozones); b) Langhian to Tortonian San Giorgio Fm., mostly composed of quartzofeldspatic sandstones (foredeep depozone); c) Tortonian to Early Messinian, quartz-feldspatic and partly sedimentary-carbonatoclastic petrofacies, thrust-top successions (Vallone Ponticello, Villanova del Battista and San Bartolomeo fms.); d) Late Messinian quartzolithic to quartzofeldspatic sandstones (Torrente Fiumarella, Anzano Molasse and Tufo-Altavilla unit), which can be referred to infilled thrust-top basins; e) unconformity-bounded Pliocene quartzofeldspatic sandstone strata (wedge-top depozones), characterized by synsedimentary tectonic activity. Detrital modes of the Serravallian through Middle Pliocene sandstones of the southern Apennines foreland basin system testify clear provenance relations from the accreted terranes forming the southern Apennine thrust-belt. The studied clastics show almost the same blended (quartz-feldspatic) composition; this condition could be related to the tectonic transport over thrust ramp of source rocks, as suggested by the tectonic evolutionary model. This study, dealing with sedimentary provenance analysis and tectonostratigraphic evolution, provides an example of the close relations between clastic compositions and foreland basin system development in southern Apennines. [ABSTRACT FROM AUTHOR]

Abstract: This study provides new data on the deformation and metamorphic evolution of the Jurassic to Upper Oligocene Frido Unit, an Ocean Continent Transition (OCT) Unit belonging to the Ligurian Accretionary Complex (LAC), by means of the integration of structural analysis, petrological investigations and a revision of the stratigraphical setting. The Frido Unit, representing the main metamorphic component of the Lower–Middle Miocene LAC in southern Italy, is characterized by a multistage tectonic evolution including: (i) two progressive deformation phases involving the development, under relatively high-pressure metamorphic conditions, of an early cleavage associated with isoclinal folds within the framework of a dominant SE-ward tectonic transport; (ii) a third deformation stage involving the growth of lower-pressure Na-amphibole along extensional shear surfaces (therefore probably marking the onset of tectonic exhumation); and (iii) two very low-temperature deformation phases characterized by the development of kink folds and associated thrusts, probably related to the late tectonic emplacement of the accretionary wedge onto the outer sectors of the Apennine domain (with a prevailing tectonic transport first toward the NE and then toward the NW). In order to clarify the metamorphic evolution of the Frido Unit, petrologic analyses were focused on its metasedimentary pelitic succession. Here, mineral parageneses including carpholite (well-documented for the first time in this study) and potassic white mica yielded peak pressure of ~1.2–1.4GPa and temperature around 350°C, thus indicating a high pressure/very low temperature metamorphism and a P–T–t path characterized by a rapid exhumation without any greenschist-facies overprint. In comparison with similar units cropping out in northern Calabria, Tuscany and Corsica, the Frido Unit experienced one of the coldest burial-exhumation histories. [Copyright &y& Elsevier]