Acid volcanism of Gemericum: comparison of the geochemistry of Ordovician and Permian volcanism

Our geochemical testing of Ordovician and Permian acid metavolcanics of Gemericum (Western Carpathians) showed some differences as well as similarities in geochemistry and geodynamic setting between them. Neither Ordovician nor Permian metavolcanics represent typical within-plate volcanism. Significant variability with at least two distinct types of metarhyolites was established within the litostratigraphic unit containing Ordovician volcanics. Our results indicate that the most of them are products of active continental margins volcanism. The Permian acid volcanics were divided by different Zr content into two distinct groups with high Zr and low Zr content, what possibly reflect the different way of their origin (fractionation vs. partial melting of continental crust). Our results are in concordance with the model of Permian volcanics origination in a post-collisional environment with the mantle source affected by the previous period of subduction. (authors)