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Facies development and sedimentary environments of the Carpathian Keuper deposits from the Tatra Mountains, Poland and Slovakia

100%

Rychliński T.

tom Vol. 78, No 1

1-18

The lower-middle Upper Triassic succession of the Fatricum domain from the Tatra Mts is commonly called the Carpathian Keuper. During Late Triassic, the Fatricum Basin was a proximal part of the central Inner Carpathian Basin. In early Carnian times, carbonate sedimentation stopped. Emersion of the Middle Triassic carbonate platform resulted in development of palaeokarst and pedogenic fabrics and deposition of conglomerates. Typical Carpathian Keuper sediments – variegated shales with intercalations of sandstones and dolomites represent mixed continental/shallow marine environments. Variegated mudstones with pedogenic carbonate concretions and intercalations of thin sandstone beds originated in mudflat environment under the semi-arid climate condition. Thick-bedded, cross-stratified sandstones with common plant debris represent fluvial deposits. They were deposited during the periods of climate pluvialisation. According to ?13C and ?18O data, thick, continuous dolomitic sediments containing local cherts represent marine sediments of perilittoral environments, which were commonly emerged as evidenced by common palaeokarst and palaeosols featuring these complexes. Cyclicity in the lower part of the Carpathian Keuper resulted from climatic changes, whereas dolomite-clastic cycles from the upper part of the succession were generated probably by sea level fluctuations. Moreover, deposition of the Keuper succession was controlled by synsedimentary tectonic which resulted in big facies variability.

Uwagi do nomenklatury skał węglanowych triasu tatrzańskiego

63%

Jaglarz P. , Rychliński T.

tom Vol. 58, nr 4

327-334

The Upper Olenekian and Middle Triassic shallow water carbonates from Tatra Mts. were hitherto described using old, descriptive nomenclature only. Moreover, some sedimentological features were also misinterpreted, for example, fenestral structures were described mostly as organic ones. Authors carried out genetic reinterpretation of these sediments and selected sedimentological structures, which allow to apply modern terminology for the mentioned carbonate rocks. Generally, dolomites with fenestral structures are interpreted as early diagenetic sabkha dolomites with pseudomorphs after sulfates (gipsum, anhydrite). Fenestral structures in dedolomites are also interpreted as evaporite pseudomorphs while those developed in mudstones are interpreted as pseudomorphs after celestite. Dolosparites, earlier described as "sugar dolomites", are actually dolomitized calcarenites (grainstones and packstones).