A new account on the Upper Jurassic stratigraphy and ammonites of the Czorsztyn succession, Pieniny Klippen Belt, Poland

Abstract

The Czorsztyn succession in the Pieniny Klippen Belt of Poland comprises, at the Rogoża klippes near Rogoźnik, the Rogoźnik Coquina Member (Lower Tithonian - Berriasian) and the Rogoża Coquina Member (Lower and Middle Tithonian) overlain by white micritic coquinas (? Upper Tithonian - Berriasian); and at the Stankowa-Skała klippe, the Czorsztyn Limestone Formation (Oxfordian - Klmmeridgian) and the Rogoźnik Member (Tithonian - Berriasian). It is suggested that the Rogoża Coquina ranges down to the Kimmeridgian (and Oxfordian ?), its lower part thus being coeval with the Czorsztyn Limestone of other sections. A new formal lithostratigraphic unit is suggested which should comprise the white micritic coquinas that form the upper part of the present Rogoźnik Member and overlie the Rogoża Member. The succession of Early and Middle Tithonian ammonites in both localities comprises i. a. the genera Semiforfmiceras, Taramelliceras, Sutneria and Simocosmoceras, the representatives of which are described and illustrated, and a new species, Semiformiceras birkenmajeri sp. n., is established. An analysis of the ammonite faunas of the classical section at Stankowa Skała allows to conclude that in the Czorsztyn Limestone there appears a stratigraphic gap which corresponds to the uppermost Callovian and Lower Oxfordian. The Mediterranean ammonite assemblages of the Late Jurassic Czorsztyn ridge show affinities with assemblages from platformic Europe and several units of the Alpine and Carpatho-Balcanic regions; this indicates migration of ammonites across bathyal basin. A special attention is paid to stratigraphic and biogeographic aspects of the genus Pseudovirgatites, and arguments are put forward in favour of approximate stratigraphic equivalence of the Middle/Upper Tithonian and Lower/Middle Volgian boundaries.