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Reconstruction of the 13.1 Ma large volume caldera-forming SAU eruption in the northeast Pannonian Basin: a case of silicic volcanism at the latest stage of subduction.

János Szepesi1,2 Péter Gál2, Dorka Gombos3, Samuel Rybar4,5, Katarína Šarinová6, Viktória Subová4, Marcel Guillong7, Maxim Portnyagin8, Maurizio Petrelli9, Dawid Szymanowski7, Olivier Bachmann7 László Fodor,10,11 Szabolcs Harangi2,3, Réka Lukács2

  • Affiliations:  1HUN-REN Institute for Nuclear Research, Debrecen, Hungary; 2MTA--HUN-REN CSFK Lendület "Momentum" PannonianVolcano Research Group, Institute for Geological and Geochemical Research, HUN-REN Research Centre for Astronomy and Earth Sciences, Budapest, Hungary; 3Eötvös Loránd University, Department of Petrology and Geochemistry, Budapest, Hungary; 4Department of Geology and Paleontology, Faculty of Natural Sciences, Comenius University Bratislava, Bratislava, Slovakia; 5Department of Geodesy and Mine Surveying, Faculty of Mining and Geology, Technical University of Ostrava, Ostrava Poruba, Czech Republic 6 Department of Mineralogy, Petrology and Economic Geology, Faculty of Natural Sciences, Comenius University, Bratislava, Slovakia 7ETH Zürich, Zürich, Switzerland; 8 GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany; 9 Department of Physics and Geology, University of Perugia, Perugia, Italy; 10 HUN-REN Institute of Earth Physics and Space Science, Csatkai E. u. 6-8 9400, Sopron, Hungary 11 ELTE Eötvös Loránd University, Institute of Geography and Earth Sciences, Department of Geology, Pázmány P. s. 1/C 1117, Budapest, Hungary 

  • Presentation type: Poster

  • Presentation time: Thursday 16:30 - 18:30, Room Poster Hall

  • Poster Board Number: 64

  • Programme No: 3.11.24

  • Theme 3 > Session 11

Abstract

The late stage of Miocene silicic volcanism occurred in the easternmost part of the Pannonian Basin (eastern-central Europe), following the syn-extensional ignimbrite flare-up event (18.1--14.4 Ma). The formation of andesite-dacite-rhyolite volcanic field in the Tokaj Mts. took place close to the presumed retreating subduction zone which contributed to the back-arc extension of the Pannonian Basin. Four silicic explosive events were recognized here, the largest one was the rhyolitic, SAU (13.1 Ma) eruption. A >500 m thick volcaniclastic succession on the eastern margin of the Tokaj Mts fills the proximal part of the caldera and contains abundant basement-derived lithics. The boreholes also revealed a preserved section of the collapsed caldera-wall. Thorough hydrothermal activity (silicification, zeolitic, and argillic alteration) modified significantly the associated deposits. However, detailed zircon geochronology and trace element geochemistry integrated with glass major and trace element geochemistry of rare fresh samples revealed the unique fingerprint of this eruption. Many sporadic pyroclastic deposits measuring several tens of meters in thickness have been identified up to 100 km from the eruption center (e.g. East Slovakian Basin). Distal tuffs in Romania were also correlated to this eruption. This implies a large, caldera-forming eruption with a VEI=7 size. The remarkably heterogeneous and evolved trace element composition suggests evacuation of several silicic melt lenses from a large silicic magma reservoir. Acknowledgements. Funds: National Research, Development and Innovation Office (No. 145905); MTA--HUN-REN CSFK Lendület "Momentum" PannonianVolcano Research Group; The Ministry of Education, Science, Research and Sport of the Slovak Republic: VEGA-1/0526/21, and APVV-23-0227