Geological map of the eastern sector of the Gorgoglione Basin (southern Italy)

Abstract

In this paper we report new stratigraphic data related to a new geological map of the Miocene Gorgoglione Basin of southern Italy,\ud traditionally considered as a piggy-back or wedge-top basin filled by a turbidite-like succession. Well exposed outcrops in the study area (eastern sector of the basin) show four unconformities in the Castelmezzano-Pietrapertosa area. Two of these unconformities pass to paraconformities southeastward, in the Cirigliano-Gorgoglione area. Based on new stratigraphic data the “succession of the Gorgoglione Flysch” can be divided into different informal units: Val Miletta formation and Gorgoglione supersynthem. The latter can be subdivided into the Cirigliano and Castelmezzano synthems. The previously established Cirigliano synthem is here divided into three subsynthems. The lowermost sediments of the Gorgoglione Flysch on the eastern sectors correspond to a complex unit (Val Miletta formation) including Numidian-like quartzarenites, Gorgoglionelike sandstones, and, at the top of the formation, an olistostrome of varicoloured clays, belonging to the Argille Variegate Group. The stratigraphic analyses and the biostratigraphic results based on calcareous plankton assemblage, improve the reconstruction of the geometries of the sedimentary bodies and the time-space facies evolution of the synthems. Sedimentologic and petrographic characters of the upper part of the Castelmezzano synthem show a clear fining and thinning upward trend. Medium- and fine-grained arenites, varying in composition from quartz sandstones to siltstones and shales, are locally marked by abundant planktonic foraminifera and are interpreted as contourites. Moreover, the relationships between tectonics and sedimentation are analyzed. The data are used to propose a scheme of the Burdigalian to Tortonian tectono-stratigrafiphic evolution of the eastern sector of the basin

Multi‐scale analysis of a migrating submarine channel system in a tectonically‐confined basin: The Miocene Gorgoglione Flysch Formation, southern Italy

“…Thrust‐faults in the Apennine accretionary wedge typically show a slip rate variability on a timescale up to 500 kyr (Gunderson et al ., ), consistent with the time span during which CS2 evolved, according to biostratigraphic data reported by Giannandrea et al . (). In this scenario, the reconstructed migration pattern of CS2 might have been influenced by the variable rate of growth of the internal, out of sequence thrust, which competed during its development with the ongoing subsidence of the basin (Fig.…”

“…Due to their lateral extension, CS2A and CS2B represent important stratigraphic markers in the GF succession (Boiano, ). Previous workers interpreted them as two distinct systems, relating their formation to the combined effect of eustatic sea‐level fall and basin modifications associated with thrust tectonics (Loiacono, ; Boiano, ; Giannandrea et al ., ). However, the convergence of the two channel belts observed in the northern sector of the study area (Fig.…”

“…Basin physiography and evolution of its sedimentary fill were controlled by the contractional tectonics affecting the Southern Apennine accretionary wedge during the late Miocene (Pescatore, , ). The deep‐water succession was deposited from the late Burdigalian to the Tortonian (Maffione et al ., ; Giannandrea et al ., ), with variable degrees of lateral confinement, provided by the growing orogen to the west and by the incipient outer thrust structures of the thrust and fold belt to the east (Pescatore et al ., ; Butler & Tavarnelli, ). Provenance data show that the GF was sourced from a crystalline basement terrane located within the orogenic hinterland to the west (Critelli & Loiacono, ; Critelli et al ., ).…”

“…workers as large submarine slump deposits (Pescatore et al, 1980;Loiacono, 1993), produced by catastrophic avalanche processes induced by seismic shocks (Boiano, 1997;Giannandrea et al, 2016). However, the marked erosional character, the concave-up geometry of the sharp bases and the systematic internal facies distribution of these very coarse-grained sandbodies indicate deposition in submarine channels from multiple sediment gravity flows.…”

Integrating traditional field methods with emerging digital techniques for enhanced outcrop analysis of deep water channel-fill deposits

“…Thrust-top clastic successions of upper Eocene to Plio-Pleistocene age unconformably cover the whole thrust-pile (Patacca and Scandone, 2007). Among them, one of the better preserved units is the late Burdigalian -early Tortonian GFF (Selli, 1962;Giannandrea et al, 2016). This ~1,950 m thick siliciclastic turbidite succession consists of coarse sandy turbidites and mudstones with subordinate conglomerates, filling a narrow and NNW-SSE oriented wedge-top basin (Boiano, 1997).…”