Mária ŠIMURKOVÁ: Geochemical study of the metamorphosed acid volcanics and volcanoclastic of the Early Paleozoic of Gemericum: petrology, subsolidus alterations and geodynamic setting. Comenius University in Bratislava, Faculty of Natural Sciences, Department of Geochemistry. Supervisor: doc. RNDr. Peter Ivan, CSc. Dissertation, 2017, 130 pp., 55 pictures, 8 supplementary materials. Key words: Gemeric superunit, Early Palaeozoic, acid metavolcanites and metavolcaniclastics, Alaskan-type subduction–accretion orogen. The thesis represents a petrological and geochemical research of acid metavolcanites and metavolaniclastics from the Gelnica, Rakovec and Smrečinka Group (Gemeric Superunit, Western Carpathians). The main goal is to contribute to the compilation of a valid geodynamic model of the Western Carpathians. The emphasis was laid on the geochemical study of subsolid alteration, primary petrological character and geodynamic setting of studied rock complexes. Within the Gelnica Group they were affected by alkali hydrothermal-metasomatic alteration, linked with the variability in alkali and mobile elements content and with the formation of stratiform sulfide and oxide mineralizations, significant for the metallogeny of area. Metarhyolites and their metatuffs of varied granularity and alteration rate represent the Cambrian-Ordovician volcanogenic unit of Gelnica Group. Metavolcaniclastics could represent metaignimbrites. They were partially redeposited into the sedimentary flysch-like facies and they are present within the Bystrý potok formation as small bodies of geochemically distinct acid metavolcaniclastics with basic admixture. They resemble metadacites, which occur only at the northern margin of Gelnica Group. It is not excluded that they are a part of a separate sedimentary unit, probably devonian in age. Two different groups of sericitic phyllites are in accordance with this hypothesis as well. The sedimentary and volcanogenic units were in pre-alpine nappe contact. The observed variability within the acid metavolcanites is in accordance with spatial distribution of the geochemical types of metabasalts. Specific primary glassy metavolcanics distinct in geochemistry and petrography found in the northeastern part of Gelnica Group arised evidently from the E-MORB basalts fractionation. The general geodynamic setting of the study area could be explained using the Alaskan-type subduction-accretion orogen model. Together with the analogical rocks from Alps and from other areas (Sardinia, Sicily, Eastern Carpathians) they could represent a silicic large igneous province (LIP) occuring in the extensional geodynamic settings of a back-arc area with continental crust. The calc-alkaline acid metavolcanics of the Smrečinka Group remindes those from the Gelnica Group, as like as the part of the Rakovec Group in the vicinity of Žakarovce village. They were possibly generated in a rifted margin of the subduction-accretion orogen. The acid metavolcanics of the majority of Rakovec Group are considerably distinct, they are paralkaline (commendites, commenditic trachytes) and they represent an unambiguous indicator of the within-plate rifting. The Vrbno Group (Hrubý Jeseník Mts., Czech republic) is a likely continuation of the Rakovec and Smrečinka Group within the European Variscides. Key words: Gemeric superunit, Early Palaeozoic, acid metavolcanites and metavolcaniclastics, Alaskan-type subduction–accretion orogen