Facies and sedimentary environments of the Upper Scythian-Carnian succession from the Belanské Tatry Mts., Slovakia

Abstract

The Triassic Fatricum basin studied in the Belanské Tatry Mts. (Slovakia) was a relatively stable and restricted platform area influenced by eustatic and climatic fluctuations. During the early Triassic the platform was influenced by continental clastic sedimentation intermittent with shallow marine transgressions when carbonate sediments formed. Common occurrence of carbonized plat debris suggests relatively humid climatic conditions dominating during this interval (Werfenian facies). Significant climate aridisation was concurrent with the beginning of the Middle Triassic transgression as indicated by evaporitic fabrics common within the entire Middle Triassic carbonate succession. The Middle Triassic has been divided into several lithofacies complexes reflecting the interplays between the eustatic and climatic fluctuations. The lower Middle Triassic complex (lower-middle Anisian?) displays dominance of calcareous sediments indicating free communication with the open ocean. The subsequent intervals are rather uniform facies assemblage composed by dolomites and evaporites formed in a restricted and stagnant basin. The basin has been strongly influenced by subtropical storms, particularly common in the late Anisian. Transgression pulse in the early Ladinian involved growth of microbial colonies building thrombolitic biostromes. Final shallowing by the end of Ladinian led to replacement of carbonate sediments by continental clastics of the Carpathian Keuper. These sediments, mostly of alluvial nature, comprise plant debris what suggests climate pluvialisation in Carnian times.