U–Pb zircon ages from Permian volcanites of the Čierna Hora Mts. (Western Carpathians, Slovakia): Regional tectonic implications

Abstract

U–Pb dating of magmatic zircons from the Permian meta-andesites of the Čierna Hora Mts. yielded the Concordia ages of 267.0±1.5 Ma, which correspond to the Guadalupian Epoch in the time span of the Wordian Stage. The sequence was correlated with the Northern Veporic Permian rocks from the Čierťaž Mts. From the geochemical point of view, the studied volcanic rocks belong to a peraluminous calc-alkaline magmatic suite, linked to the post-collisional lithospheric extension. Lithosphere extension and attenuation will promote upwelling of hot asthenosphere. In this context, the calc-alkaline affinity may result through extensive crustal contamination of basaltic magma. Continuous extensional setting, succeeded by overheating is indicated by the newly formed zircon rims of 252.2±3.2 Ma age at the edges of the Wordian zircon grains. The Neoproterozoic (618±8 Ma) and Paleoproterozoic (2080±13 Ma) ages were found within the xenocrystic cores in the studied magmatic zircon grains. The presented xenocrystic zircon ages indicate derivation from the Variscan basement rocks with reworked fragments of Cadomian crust.