The granite system near Betliar village (Gemeric Superunit, Western Carpathians): evolution of a composite silicic reservoir

Abstract

Boron-and fluorine-rich highly evolved granites in the Betliar area (Gemeric Unit, Western Carpathians) represent composite intrusion that formed probably during two distinct magmatic episodes. During the first stage, evolved granitic magma originating from an underlying volatile-rich reservoir intruded into an open fault system in the form of sill-like bodies and crystallized as equigranular or medium-to fine-grained rocks. The subsequent volatile flux enhanced postmagmatic alterations of the solidified granites and led to the formation of greisens with elevated amounts of tourmaline and Nb-Ta-W-Th phases. During the second stage, magma from a deeper magmatic reservoir intruded as a mush containing K-feldspar, albite, mica and quartz phenocrysts and gave rise to porphyritic granites. Partial dissolution and corrosion of the phenocrysts was enhanced by a pressure drop during emplacement of the porphyritic granites into middle-crustal level where the volatile-rich residual melt rapidly crystallized and is now preserved as quartz-albite-K-feldspar matrix with tourmaline and other accessories. Monazite and zircon geochronology indicates that the process occurred during Middle and Late Permian, and possibly extended to Early Triassic.

Compositional variations in tourmalines from peraluminous rocks of the Dipilto Granitic Batholith, Eastern Chortis Terrane, Nicaragua: tracers of magmatic to hydrothermal evolution

“…This evolutionary trend is different from other F-rich granite systems (Fig. 11a) previously published from many localities (Sinclair and Richardson 1992;Buriánek and Novák 2007;Kubiš and Broska 2010). 7.3. evolution of boron-rich melt in the Dipilto Batholith…”

Continuity and Episodicity in the Early Alpine Tectonic Evolution of the Western Carpathians: How Large‐Scale Processes Are Expressed by the Orogenic Architecture and Rock Record Data

“…The Lower Paleozoic complexes are intruded by Permian, postorogenic, tin-bearing S-type granites (Finger et al, 2003;Finger & Broska, 1999;Kubiš & Broska, 2010;Poller et al, 2002). The post-Variscan, Pennsylvanian-Permian-Triassic sedimentary cover of the Gemeric basement consists of terrestrial clastics and marine carbonates.…”

Fluorarrojadite-(BaNa), BaNa4CaFe13Al(PO4)11(PO3OH)F2, a new member of the arrojadite group from Gemerská Poloma, Slovakia

“…The granitic rocks of the Gemeric Unit represent a distinct type of specialized (Sn–W–F), highly evolved suite with S-type affinity, which differs from other granitoids occurring in the Veporic and Tatric Units of the Western Carpathian crystalline basement; they are enriched in phosphorus and rare lithophile elements, such as Li, Rb, Cs, B, Ga, Sn, W, Nb, Ta and U and depleted in rare-earth elements, Zr, Ti, Sr and Ba (e.g. Uher and Broska, 1996; Petrík and Kohút, 1997; Kubiš and Broska, 2005, 2010; Breiter et al , 2015). The Gemeric granitic rocks form several small plutons intruded into the intensively folded Lower Paleozoic (mainly Ordovician to Devonian) volcano-sedimentary complex of the Gelnica Group, metamorphosed in the greenschist metamorphic facies (Bajaník et al , 1984; Petrasová et al , 2007).…”