The abundance of 51 elements and petrovolumetric models of the calabria crust: Curinga - Stilo area (site 6)

8.1.1. GENERAL FEATURES SITE LOCATION IN GEOLOGIC SENSE: the site is located in the Serre (southern Calabria) where a near complete section of the continental crust as left by Hercynian orogeny crops out. SITE LOCATION IN TOPOGRAPHIC SENSE: the site was studied using geological sections from Curinga to Monterosso up to Stilo along N-S and NW-SE directions. LENGTH OF TRANSECT: about 45 km WIDTH OF TRANSECT: 4-5 km N° OF LITHOLOGIES CROSSED (REFERRING TO THE 1:100.000 GEOLOGICAL MAP): a recent geological map (scale 1:100.000) is lacking; a geological map (scale 1:25.000) has been published by Cassa per il Mezzogiorno; local geological maps have been published by italian and foreign researchers. The main lithologies are 12. LITHOLOGIES CROSSED: Metagabbros, felsic and mafic granulites, metapelites, leucosomes, metagreywackes, metabasites, tonalites, granodiorites, granodiorite with K-feldspar megacrysts, peraluminous granites, phyllites, paragneisses, metavolcanites, marbles. BRIEF DESCRIPTION OF THE STRUCTURAL SETTING: in the lower crust the main foliation is NE-SW directed, locally E-W, and it deeps southward. The granitoids are intruded between the lower and upper crustal segments. BRIEF DESCRIPTION OF THE LITHOSTRATIGRAPHIC SEQUENCES: the lower crustal section is about 7-8 km thick. Calc-alkaline layered metagabbros and felsic and mafic granulites with intercalations of metapelites and minor bodies of metaultramafites, about 2 km thick, underlie a migmatic metapelitic unit having a thickness of about 5-6 km, which consists of migmatites with concordant and discordant leucosomes having trondhjemitic and granitic compositions; minor metabasites and marbles are also present in the metapelitic portions. At the top of the metapelitic unit, towards the plutonites, a wide border zone consisting of metapelites, plutonites and leucosomes with strong deformation is distinguishable. Towards south foliated and massive tonalites, intruded in rock-types of the lower crust and K-feldspar megacryst granitoids and granodiorites intruded in lithologies of the upper crustal segments. AGE OF PROTOLITHS: the age of low-grade metasediments in the upper crust is Ordovician-Carboniferous, the granitoids have Hercynian age and the lower crustal rocks, probably, derived from pre-Cambrian sediments and include metaigneous rocks monitoring magmatic age of 550 Ma.(Schenk 1980). AGE OF METAMORPHISM: the lower and upper crustal rocks show hercynian metamorphism (300 Ma) and local alpine effects. MINIMUM NUMBER OF REPRESENTATIVE SAMPLES: 80 NUMBER OF PLANNED CHEMICAL ANALYSES: 55 NUMBER OF PLANNED GEOCHEMICAL ANALYSES: 55 NUMBER OF PLANNED ISOTOPIC ANALYSES: 13 NUMBER OF DESIRABLE PETROPHYSICAL MEASUREMENTS: - WHICH TYPE OF CRUST DOES THE SITE REPRESENT? Upper and lower hercynian continental crust