International Geological Journal - Official Journal of the Carpathian-Balkan Geological Association

Lithofacies and age data of Jurassic foreslope and basin sediments of Rudabanya Hills (NE Hungary) and their tectonic interpretation

Pages: 351 - 379

Authors: SZILVIA KOVER, JANOS HAAS, PETER OZSVART, AGNES GOROG, ANNETTE E. GOTZ, SANDOR JOZSA

Abstract: Jurassic sedimentary rocks of the Telekesvölgy Complex (Bódva Series), Telekesoldal Complex (Telekesoldal Nappe) and the Csipkes Hill olistostrome in Rudabanya Hills (NE Hungary) were sampled for microfacies studies and interpretation of the depositional environments. The Telekesvölgy Complex is made up of reddish to greenish marl, occasionally containing limestone olistoliths — gradually progresses from the Norian Hallstatt Limestone of the Bódva Series — then grey marl, which may correspond to the latest Triassic Zlambach Formation. This variegated marl progresses into grey marl and calcareous marl, containing crinoid fragments. It may be interpreted as a hemipelagic facies, relatively close to submarine highs. Bajocian to Lower Bathonian black shales, rich in radiolarians and sponge spicules representing typical deep pelagic facies, are also assigned to the Telekesvölgy Complex. The Telekesoldal Complex represents a melange-like subduction-related complex that consists of black shales, sandstone turbidites and olistostrome beds, and deposited by gravity mass flows. A relatively deep marine basin in the proximity of a submarine slope is likely to be the depositional environment of this unit. The clasts of the olistostromes are predominantly Middle to Upper Triassic pelagic limestones, rhyolite and basalt. Subduction related nappe stacking of the ocean margin during the Middle to Late Jurassic may have created suitable conditions for this sedimentation pattern. Bajocian–Callovian age of the complex was proved by the revision of the radiolarian fauna and new palynological data, the first from the Jurassic of the Aggtelek-Rudabanya Hills. The Csipkes Hill olistostrome consists of carbonate turbidite beds containing Jurassic platform derived foraminiferal and olistostrome horizons with Middle–Upper Triassic limestone clasts of red Hallstatt facies.

Keywords: Jurassic, Neotethys, subduction-related complex, mass-flows, microfacies, Foraminifera, Radiolaria, palynomorphs

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