Tracing widespread Early Miocene ignimbrite eruptions and petrogenesis at the onset of the Carpathian-Pannonian Region silicic volcanism

Autor: Mihovil Brlek, Simon Richard Tapster, Julie Schindlbeck-Belo, Sean P. Gaynor, Steffen Kutterolf, Folkmar Hauff, Svetoslav V. Georgiev, Nina Trinajstić, Sanja Šuica, Vlatko Brčić, Kuo-Lung Wang, Hao-Yang Lee, Christoph Beier, Adam B. Abersteiner, Ivan Mišur, Irena Peytcheva, Duje Kukoč, Bianka Németh, Mirka Trajanova, Dražen Balen, Marcel Guillong, Dawid Szymanowski, Réka Lukács
Rok vydání: 2023
Předmět:
Zdroj: Gondwana Research. 116:40-60
ISSN: 1342-937X
Popis: The Carpathian-Pannonian Region (CPR) hosted some of the largest silicic volcanic eruptions in Europe during the Early and Middle Miocene, contemporaneously with major lithospheric thinning of the Pannonian Basin. This was recorded as an ignimbrite flare-up event from approximately 18.1–14.4 Ma. To gain in-depth perspectives on the eruption chronology, tephrostratigraphy, and petrogenesis at the onset of CPR silicic volcanism, we applied a multi-proxy approach to Lower Miocene rhyolitic ignimbrites and pyroclastic fall deposits from the northern CPR to the Dinaride Lake System. High-precision zircon U-Pb geochronology distinguished two Lower Miocene groups of volcaniclastic rocks at ∼ 18.1 Ma and ∼ 17.3 Ma. Based on combined tephrostratigraphic signatures we propose that the ∼ 18.1 Ma Kalnik and ∼ 17.3 Ma Eger eruptions produced widespread (intermediate to) large caldera-forming massive rhyolitic ignimbrites, deposited across northern and southwestern regions of the CPR. Due to easterly winds that carried volcanic ash hundreds of kilometers to the southwest, Eger eruption products also reached distal intra-montane Dinaride lacustrine basins, recorded as pyroclastic fall deposits. Heterogeneous major and trace elemental compositions of ∼ 18.1 Ma volcanic glass shards suggest that the Kalnik eruption was sourced from complex silicic magmatic systems, with simultaneous tapping of two discrete melt bodies during the eruption. The homogeneous geochemical composition of ∼ 17.3 Ma glasses is distinct from the older glasses. Integrated zircon and bulk glass Nd-Hf isotope compositions have a positive correlation, defining a regional mantle array, and are more radiogenic in the younger phase of volcanism. The recorded systematic isotopic change, moving from older more crustal signatures to younger more juvenile compositions, imply that during the period of lithospheric thinning of the Pannonian Basin the region underwent more complex variations in the interaction between metasomatized lithospheric mantle-derived magmas and various crustal components than previously recognized.
Databáze: OpenAIRE