Middle Triassic evolution of the Tatricum sedimentary basin: an attempt of sequence stratigraphy to the Wierchowa Unit in the Polish Tatra Mountains

Abstract

Ewolucja i stratygrafia sekwencyjna środkowego triasu basenu tatricum na podstawie badań jednostki wierchowej Tatr Polskich The paper focuses on paleoenvironmental reconstruction and sequence stratigraphy of the Tatricum Basin for the late Scythian-Ladinian interval. The reconstruction is based on observations carried out in the Kominiarski Wierch section, situated in the Polish part of the Tatra Mts. Sedimentological and geochemical studies indicate that during middle Triassic time the Tatricum Basin was situated upon an isolated and restricted carbonate platform dominated by shallow water carbonate and evaporitic sedimentation. The basin was a tectonically stable area controlled by eustatic fluctuations. Incipient tectonic movements first occurred in late Ladinian time only. The studied sedimentary succession is composed of several stacked, shallowing-upward cycles that are interpreted as 3rd order depositional sequences. The constructed sedimentary sequence framework corresponds well with the sequence stratigraphic scheme of the Northern Alpine Triassic and enables a better chronostratigraphic resolution of the Triassic in the Tatra Mts.