Acta Geologica 44. (2001)

1. szám - M. Kovác - A. Nagymarosy - K. Holcová - N. Hudácková - A. Zlinská: Paleogeography, paleoecology and eustacy: Miocene 3rd order cycles of relative sea-level changes in the Western Carpathian - North Pannonian basins

MAGYAR rmíüMÁNYOS AKADÉMIA KÖNYVTÁRA 30220 Michal Kovác Department of Geology and Paleontology, Comenius University, Bratislava Katerina Holcová Dept, of Paleontology, Charles University, Prague Adriana Zlinská Geological survey SR, Bratislava Acta Geologica Hungarica, Vol. 44/1, pp. 1-45 (2001) Paleogeography, paleoecology and eustacy: Miocene 3rd order cycles of relative sea-level changes in the Western Carpathian - North Pannonian basins András Nagymarosy, Department of Geology, Eötvös Loránd University, Budapest Natalia Hudácková Department of Geology and Paleontology, Comenius University, Bratislava, Interaction of sea-level changes and tectonics had an important influence on the paleogeography and thereby also on the paleoenvironment of the Western Carpathian - North Pannonian Basins, which formed the northern bays of the Central Paratethys epicontinental sea in the Miocene. The depth and the shape of the basins were predominantly controlled by the main tectonic events. Relative eustatic changes reflected in coastal onlaps were followed mostly by the rise of water paleodepth in the offshore environment. The correlation of the constructed curves for the coastal onlap and estimated paleodepth with the global reference curves (Haq et al. 1988; Haq 1991) shows some discrepancies, predominantly caused by tectonics during the basin development. The Late Egerian-Early Eggenburgian isolation or erosion was followed by the Eggenburgian transgression (ca. 21 Ma; NN2 zone) and deepening of the sedimentary environment in the Western Carpathian - North Pannonian Basins. Later on, during the Ottnangian (NN3 zone), a brackish paleoenvironment developed in the Vienna and the Danube Basins (ТВ 2.1 global cycle;Haq et al. 1988). In the East Slovakian Basin the Ottnangian uplift was associated with hiatus, unlike the Novohrad Basin, where deposition of the continental coal-bearing formations passed upward into the regional highstand deposition characterized by lacustrine to brackish environment with the Late Ottnangian marine ingressions. The Early Karpatian (NN4 zone) transgression and highstand in the Western Carpathian - North Pannonian Basins can be correlated with transgression and global sea-level rise of the ТВ 2.2 global sea-level cycle (Haq et al. 1988). In the East Slovakian Basin the local sea-level fall at the late highstand led to salinity crisis. The following Late Karpatian-Early Badenian sea-level cycle (NN4 zone) is observable only in the East Slovakian and the Novohrad Basins and it can be correlated with the ТВ 2.3 global cycle (Haq et al. 1988). In the Vienna and Danube Basins the erosion of uplifted areas or terrestrial deposition in the depressions occurred. Addresses: M. Kovác, N. Hudácková: Mlynska dolina G, Bratislava, Slovakia 842 26 E-mail:Kovacm@fns.uniba.sk K. Holcová: Albertov 6, Praha, Czech Republik, 12 843, Holcova@prfdec.natur.cuni.cz A. Zlinská: Mlynska dolina 1, Bratislava, Slovakia 842 26, Zlinska@gssr.sk A. Nagymarosy: H-1088 Budapest, Múzeum krt. 4/a, Hungary, Gtorfo@ludens.elte.hu Received: 14 October, 1999 0236-5278/2001/$ 5.00 © 2001 Akadémiai Kiadó, Budapest

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