Biostratigraphy and microfacies of Middle-Late Triassic formations in the Rudabánya Mountains (NE Hungary)

This master thesis focuses on research areas in the Telekes Valley and around Szőlősardó (NE-Hungary), which are situated in the Rudanbánya Mountains as part of the Inner Western Carpathians of the ALCAPA Megaunit in the Circum Pannonian Region. In general, the following three tectonic units were studied: The Telekesvölgy Complex (TVC), the Telekesoldal Complex (TO) and the Szőlősardó Unit. The Telekesvölgy Complex and the Telekesoldal Complex are described in literature as Jurassic formations (e.g. shale, radiolarite, olistostromes, sandstone) of the Bódva Unit. Last one may display non-metamorphic Triassic rocks and Bódvalenke Limestone, a most-distal deep-water facies as a transition between Hallstatt facies and red radiolarite. The Szőlősardó Unit is treated as a platform-near, grey facies or subunit and consists of varicolored limestone (Pötschen and Nádaska Limestone). The observed area in the Telekes Valley comprises sections of the Telekesvölgy and Telekesoldal Complex, but generally reworked. Microfacies analysis and determination of conodont taxa including CAI (Conodont Alteration Index) provide insight into the attribution of samples to the low-metamorphosed Telekesoldal Complex (quarry by Szőlősardó with CAI=5,0-5,5) and the Telekesvölgy Complex (Telekes Valley 6 and 8 profiles and Telekes Valley breccia with CAI=5,5-6,0). The Szőlősardó Unit shows diverse conodont colors, CAI-values around CAI 1,0-2,0 and is therefore non-metamorphic. Properties of breccia sections in the Telekes and Szőlősardó area represent Mass Transport Deposits (olistostromes, debris flows) with different thermal overprint. The Telekesvölgy Complex above the Hallstatt Limestone sequence and Bódva Unit appears metamorphosed and comprises Jurassic components, shallow-water blocks and reworked Triassic Hallstatt material in the form of Mass Transport Deposits (olistostromes, debris flows). In sum, Jurassic imbricates (Telekesoldal and Telekesvölgy Complex) in the Telekes Valley and far travelled nappes/units (Szőlősardó Unit) support the argument of allochthonous concepts. The Bódvalenke Limestone is interpreted as a most distal Hallstatt Limestone type with less resedimented material, almost on the transition to the continental slope. The results lead to the tectonostratigraphic model as followed: The Telekesoldal Complex as the lowermost nappe and the Telekesvölgy Complex above overthrust during Middle-Late Jurassic obduction of the Neotethyan Ocean. The far-travelled Szőlősardó Unit and other non-metamorphic units were juxtaposed during Cretaceous Carpathian orogeny. The Perkupa Evaporite Formation may act as a shear horizon on the base of the Szőlősardó Unit. Miocene shear tectonics and nappe stacking dismembered units and led to the current arrangement of the nappes. The results obtained in this thesis support the argument for allochthonous concepts.