The carbonate tectonic units of northern Calabria (Italy): a record of Apulian palaeomargin evolution and Miocene convergence, continental crust subduction, and exhumation of HP–LT rocks

Abstract

In northern Calabria (Italy), the metasedimentary succession of the Lungro–Verbicaro tectonic unit preserves mineral assemblages suggesting underthrusting to depths in excess of 40 km. Internal deformation of these rocks occurred continuously during the following decompression. Index mineral composition associated with progressively younger tectonic fabrics indicates that a substantial part of the structural evolution took place within the blueschist-facies P – T field. Despite their tectonic and metamorphic history, the rocks of the Lungro–Verbicaro Unit preserve significant sedimentary and palaeontological features allowing correlations with successions included in adjacent thrust sheets and the reconstruction of the Mesozoic continental margin architecture. The subduction–exhumation cycle recorded by the Lungro–Verbicaro Unit is entirely of Miocene age. This portion of the Apulia continental palaeomargin was involved in convergence-related deformation not earlier than the Aquitanian. The integration of our results with available constraints on the tectonic evolution of the Apennine–Calabrian Arc system suggests that subduction and most of the subsequent exhumation of the Lungro–Verbicaro Unit occurred, up to Langhian time, at maximum vertical rates in excess of 15 mm a −1 . The exhumation process was then completed, at much slower rates (<2 mm a −1 ) in Late Miocene time, as indicated by both apatite fission-track data and stratigraphic information.

Multi-Analytical Approach for Identifying Asbestos Minerals In Situ

“…This is a nappe pile, which can be described as the superposition of three major structural elements that represent different paleogeographic domains: (i) The Apennine Units Complex made up of Mesozoic sedimentary and metasedimentary successions (Trias-Miocene) [47]; (ii) The structurally intermediate allochthonous Alpine Liguride nappe (Tithonian-Neocomian) made up of a series of Alpine metamorphic units including a Cretaceous-Paleogene metapelitic-ophiolitic-carbonate assemblage [41,46]; (iii) The Calabride Complex formed by Hercynian and pre-Hercynian gneiss, granite and metapelite. The Liguride nappe consists of HP-LT ophiolitic sequences, in which a metabasic and metaultramafic association constitutes the basis of a complex metasedimentary cover, ranging from pelagic to flyschoid types of sediments [41].…”

The Crati River Basin: geomorphological and stratigraphical data for the Plio–Quaternary evolution of northern Calabria, South Apennines, Italy

“…The tectonic sketch map reporting the main tectonic features is shown in the inset on the bottom left. The study area (Crati Basin) is indicated by the inset on the bottom centre (modified after Robustelli et al 2014 (Van Dijk et al 2000;Bonardi et al 2001;Butler et al 2004;Iannace et al 2007).…”

Seismotectonics and landslides of the Crati Graben (Calabrian Arc, Southern Italy)

“…Tectonic units of the Chain Carbonate-Apennine Complex Prevalent Triassic dolostone and metalimestone (Monte Cocuzzo Unit), outcropping in 'tectonic windows' along the southern edge of the Coastal Chain horst, and Mesozoic to Langhian succession constituted by phyllites, metalimestone, dolostone and calcarenites and marls, with turbiditic strata (LungroVerbicaro Unit) (Iannace et al, 2007), outcropping in the north-western extremity of the study area.…”