Naslov
The oldest Miocene volcaniclastics of the Carpathian–Pannonian Region based on U–Pb zircon LA-ICP-MS dating in the Mura Depression (Northwestern Croatia)

Autori
Matošević, Mario ; Šuica, Sanja ; Wall, Corey J. ; Mužina, Marina ; Vranjković, Alan ; Zopf, Dina ; Jović, Goran

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
36th International Meeting of Sedimentology Abstracts Book / Vlahović, Igor ; Matešić, Darko - : Hrvatsko geološko društvo, 2023, 318-318

ISBN
978-953-6907-79-3

Skup
36th International Meeting of Sedimentology

Mjesto i datum
Dubrovnik, Hrvatska, 12.06.2023. - 16.06.2023

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
vulkanoklastične stijene, miocen, geokronologija, Panonski bazenski sustav, Murska depresija
(Volcaniclastic rocks, Miocene, Geochronology, Pannonian Basin System, Mura Depression)

Sažetak
Volcaniclastic rocks are important markers in the stratigraphic correlation of deposits and interpretation of the evolution of sedimentary basins, especially when there are no reliable biostratigraphic data. These rocks have been drilled in more than 20 exploration wells in the Mura Depression (Hrvatsko Zagorje Basin) in Northwestern Croatia (SW part of the Pannonian Basin System). They cover more than 235 km2 of the exploration area and are of considerable thicknesses (>1500 m in successions in some wells). Several methods have been used to reveal characteristics of the rocks: petrographic analyses with macroscopic and microscopic (thin section) examinations using polarizing light microscopes, geochemical analyses of major and trace elements using ICP-MS and ICP-ES, geochronological analyses using U–Pb LA-ICP-MS on zircons, as well as rocks’ comparison and correlation using 2D and 3D seismic and well-log data. Volcaniclastic rocks are mostly crystaloclastic, lithoclastic, and vitroclastic tuffs, lapilli tuffs, and lapillistones, subordinately pyroclastic and tuff breccias, and tuffites. To a lesser extent, extrusive rocks are also present. The rocks are mainly classified as dacite, andesite, and, to a lesser degree, rhyolite, and belong to calc-alkaline and high-K calc-alkaline series. They are characterized by the enrichment of incompatible trace elements compared to compatible ones, with the ubiquitous negative Nb–Ta anomaly. Geochronological analyses yielded ages of eruptions and depositions of the volcanic material in the range of 23.45–20.98 Ma (23.19±0.26 to 21.23±0.25 Ma). The study covered large volumes of volcaniclastics which indicate significant and strong volcanic activities at the transition from the Paleogene (Oligocene – Chattian) to the Neogene (early Miocene – Aquitanian). Large thicknesses of the rocks indicate volcanic eruptions that continued during the Aquitanian, i.e., Egerian and Eggenburgian stages according to the Central Paratethys stratigraphic division. These rocks are the oldest volcaniclastics of the Miocene epoch in this part of Croatia and in the wider area of the Pannonian Basin System. It remains an open question whether they reflect volcanism related to the Periadriatic lineament of the Alps or one related to the initial opening of the Pannonian Basin System.

Izvorni jezik
Engleski

Znanstvena područja
Geologija

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