Dike magmatism in the Sila Grande (Calabria, southern Italy): Evidence of Pennsylvanian–Early Permian exhumation

Abstract

A dike network transecting a basement of intrusive and metamorphic rocks\ud related to the Hercynian orogeny is exposed in the Sila Grande (southern\ud Italy). Dike magmatism, similarly to other regions of the western\ud Mediterranean, such as Sardinia, Corsica, and Catalonia, is of\ud calc-alkaline to alkali-calcic affinity. Zircon U-Pb geochronology\ud indicates that dike magmatism took place between 295 +/- 1 to 277 +/- 1\ud Ma, after the main late Hercynian emplacement of granitoids (306 +/- 1\ud Ma). Barometry indicates that the basement underwent exhumation of 8 +/-\ud 3 km before dike injection. The dike network has a geometrical\ud arrangement consistent with a transtensional stress regime that resulted\ud in ductile thinning of the lower crust during the late stage of the\ud Hercynian orogeny and concurrent fracturing of the upper crust that made\ud possible magma ascent through dikes. The proposed tectonic evolution is\ud related to dismemberment of the southern Hercynian belt in the central\ud Mediterranean area as a result of dextral transtension of Gondwana in\ud relation to Laurasia during the Pennsylvanian-Early Permian

Time Constraints on the Building of the Serre Batholith: Consequences for the Thermal Evolution of the Hercynian Continental Crust Exposed in Calabria (Southern Italy)

“…Conversely, a peak at about 280 Ma, highly visible for the lower crust, apparently does not match with an important magmatic event. Indeed some dates in both tonalite and granodiorite from the Serre batholith cluster around 280 Ma, and felsic dikes in the Sila Massif provided ages from 281 to 277 Ma (Liotta et al 2008;Festa et al 2010). Similar dikes, ranging in composition from andesite to dacite-rhyodacite and showing a transitional affinity from medium-to high-K calcalkaline, were also described in the Serre Massif by Romano et al (2011).…”

“…was obtained by Lima et al (2012) for construction of the Hercynian Pavia Pluton (Ossa-Morena zone, Portugal). In addition, our geochronological data fall in the time window (314-293 Ma) regionally defined by the U-Pb method for the late-Hercynian plutonism in the CalabriaPeloritani terrane (ID-TIMS zircon, monazite, and xenotime ages: Schenk 1980Schenk , 1990Caggianelli et al 2000b;Graessner et al 2000; SHRIMP zircon ages: Fiannacca et al 2008; LA-ICP-MS zircon ages: Festa et al 2010).…”

Hercynian subduction‐related processes within the metamorphic continental crust in Calabria (southern Italy)

“…A late magmatic event occurred in the Serre Massif and was characterized by porphyritic, mafic and felsic dykes, that crosscut upper crustal rocks (Romano, Cirrincione, Fiannacca, Lustrino, & Tranchina, 2011). A middle Permian age was attributed to these dykes (Langone et al, 2014) based on the similar emplacement level and composition with the c. 280 Ma (U-Pb on zircons) rhyolitic to dacitic dykes of the Sila Massif (Festa, Langone, Caggianelli, & Rottura, 2010).…”

Poly-Orogenic Melting of Metasedimentary Crust From a Granite Geochemistry and Inherited Zircon Perspective (Southern Calabria-Peloritani Orogen, Italy)

“…After the thickening-related baric peak, scattered small late Carboniferous (∼314-300 Ma) early post-collisional plutons of weakly to strongly peraluminous leucotonalite to leucogranite were emplaced (Rottura et al, 1993;Graessner et al, 2000;Fiannacca et al, 2005Fiannacca et al, , 2008Fiannacca et al, , 2019. These were followed by batholith-scale magmatism at 300-290 Ma (Rottura et al, 1990;Del Moro et al, 2000b;Langone et al, 2014;Fiannacca et al, 2015Fiannacca et al, , 2017 and finally by late-to post-orogenic rhyolitic to andesitic dykes (Festa et al, 2010;Romano et al, 2011Romano et al, , 2012, heralding the early breakup of Pangea (Barca et al, 2010;Cirrincione et al, 2014Cirrincione et al, , 2016.…”