Rhaetian/Hettangian palynomorphs of the Tatra Mountains (West Carpathians)

The uppermost Triassic and the lowermost Jurassic clastic-carbonate strata of the Sub-Tatric (Kriżna) unit of the Polish Tatra Mountains yield an important assemblage of microfossils - mostly foraminifers and also palynomorphs. The three representative Triassic/Jurassic boundary sections of the Kriżna unit (Lejowa Valley, Strążyska Valley and Mt. Mały Kopieniec) have been studied and sampled in order to establish a stratigraphical succession of microfossils. The palynomorph assemblage (spores, pollen grains and dinoflagellate cysts) were found in the transitional beds of the Fatra Formation (Rhaetian) and the basal clastics of the Kopieniec Formation [Hettangian-Sinemurian(?)] - Fig. 1. The assemblage contains 58 spore and pollen species and is dominated by pteridophyte spores (Dictyoniaceae and Matoniaceae). The biostratigraphically significant taxa: Concavisporites, Dictyophyllidites and Leptolepidites, indicate Rhaetian/Hettangian time interval (Fig. 1) - see Zavattieri, Batten (1996). The facies development and floral and faunal assemblages of the Triassic/Jurassic boundary sequence in the Kriżna unit are characteristic for the shallow-marine sedimentary environment (shoreface-offshore). The data presented support the earlier views (Goetel 1917; Gaździcki 2003) that the environmental conditions prevailing in the Tethys realm were quite similar to those in the epicontinental basin of the northwestern Europe during the Early Liassic times.