Neogene tectonostratigraphic evolution of allochthonous terranes in the eastern Calabrian foreland (southern Italy)

Along the Ionian side of the Calabrian Arc, Neogene-Quaternarysuccessions overlie the Hercynian basement made up of crystallinemetamorphictectonic units and their Mesozoic-Tertiary cover. TheNeogene successions rest unconformably along the eastern border ofthe Sila Massif and form the Neogene basin fills. In the external portionof basins, Oligocene-Lower to Middle Miocene clastic successions,overling the variegated clay of the Sicilide Complex, outcrop.The Miocene-Quaternary evolution of the northern Calabria wasmainly associated with the accrectionary processes creating Miocenewedge-top depozones onto the growing orogenic belt and flexedAdria passive margin. Middle Miocene deposits accumulated in longitudinalwedge-top depozones of the Calabrian foreland-basin system,partitioned into three depocentres: the Rossano, Cirò, and Crotonebasins. The surface, subsurface and aerial-photo analyses has providednew geological data, which better define the architecture anddevelopment of the allochthonous terranes outcropping in the northeasternwedge-top basins of the Calabrian Arc. The main onland outcropof allochthonous units is represented by the so-called CariatiNappe. Structural investigations allowed to characterize the surfaceand subsurface tectonic structures detailing the style and timing ofthe Cariati Nappe emplacement. This structure consists of a complexNW-SE oriented back-thrust (top to the west) propagated startingfrom the late Tortonian time. During Messinian-Pleistocene theallochthonous terranes were involved and reworked by left-lateralNW-SE oriented transpressive fault zones. Progressive propagationof these transpressive structures compartmentalised pre-Messinianformerly continuous basin, creating distinct asymmetric depocentresduring the Messinian and Pliocene. The entire Ionian Calabrianmargin experienced accretion during the Neogene in consequence ofwhich portion of Varicoulered Clays, overlain by Oligocene-Miocenesuccessions, were extruded and emplaced into the wedge-top basins.