POLSKIE TOWARZYSTWO MINERALOGICZNE – PRACE SPECJALNE MINERALOGICAL SOCIETY OF POLAND – SPECIAL PAPERS Zeszyt 24, 2004; Volume 24, 2004 Jan GOLONKA 1 , 2 , Michał KROBICKI 2 , Nestor OSZCZYPKO 2 , Ewa SŁABY 3 , Tadeusz SŁOMKA 2 , Igor POPADYUK 4 , Aleksandr NETCHEPURENKO 5 MESOZOIC VOLCANISM ASSOCIATED WITH TRIPLE-JUNCTION ZONE OF THE EASTERN CARPATHIANS (UKRAINE) Abstract: Jurassic volcanic rock series present sequence of tholeitic – calc-alkaline – alkaline composition. Very probably the rocks are cogenetic and related to subduction environment. The published data on their geochemistry comprises major element concentrations. The rough information on trace elements doesn’t allow concluding on the origin and evolution of the melts leading to the sequence formation. Keywords: volcanism, tholeitic – calc-alkaline – alkaline series, subduction, arc island, hot spot, major elements. INTRODUCTION The presumable triple-junction zone follows the Pieniny Klippen Belt-Magura basin (first arm), Silesian (second one) and its extension into the Rahiv-Sinaia zone (third one). Jurassic-Cretaceous volcanism is associated with the zone and might be related to major plate reorganization taking place during the Tithonian time (Golonka et al. 2003, Krobicki et al. 2004). The new Atlantic spreading entered the area between the New Foundland shelf and Iberia. The closure of the Meliata- Halstatt Ocean is related to the cessation of spreading in Atlantic Tethys. The Jurassic Alpine Tethys system was abandoned. The change was accompanied by the presumed origination of subduction zone along the margin of Pieniny Klippen Belt Basin. The age, character and polarity of the presumed subduction are not fully explained. We were assuming the southern dipping of the subduction and its location under the southern margin of the Pieniny Klippen Belt Basin. The northern dipping of the subduction and its location under the northern margin of the Pieniny Klippen Belt Basin is also possible. JURASSIC VOLCANISM – CURRENT STATE OF RECOGNITION AND INTERPRETATION 1 Jagiellonian University, Institute of Geological Sciences, 30-063 Kraków, ul. Oleandry 2a 2 University of Science and Technology, 30-059 Kraków, ul. Mickiewicza 30 3 Institute of Geochemistry, Mineralogy and Petrology, University of Warsaw, 02-089 Warszawa, Al. Żwirki i Wigury 93; E.Slaby@uw.edu.pl 4 Geological Institute of Ukraine, Lviv, Mickiewicza sq. 10 5 Transcarpathian Geological Expedition, Rahiv, Mira 236 45