Dinoflagellate cysts from the Szlachtowa Formation (Jurassic) and adjacent deposits (Jurassic-Cretaceous) of the Grajcarek Unit at Szczawnica-Zabaniszcze (Pieniny Klippen Belt, Carpathians, Poland)

摘要

The Jurassic-Cretaceous fine-clastic dark deposits of the Grajcarek Unit (Pieniny Klippen Belt, Carpathians, Poland) show lithological similarities, which may lead to erroneous age correlations. Their well-exposed outcrop at Szczawnica--Zabaniszcze allows detailed sampling for their precise age determination. For this purpose, dinoflagellate cysts have been studied from a set of samples collected from the Szlachtowa, Opaleniec, Pieniny Limestone, Kapusnica and Wronine formations exposed at that site (additional sample from the Pieniny Limestone Formation was studied). The Szlachtowa Formation, a very characteristic lithostratigraphic unit, which consists of black shale and sandstones extremely rich in mica flakes, occasionally referred to literature as the so-called "black flysch", yielded rich and well-preserved assemblages. Their age is Middle Jurassic, spanning the Aalenian to Lower Bajocian. The exposures of the Szlachtowa Formation at Szczawnica-Zabaniszcze are located close to the outcrops of the Opaleniec Formation. The calcareous spotted shale from this lithostratigraphic unit yielded rich dinoflagellate cyst assemblage characteristic for Late Bathonian (Early Callovian?). The Opaleniec Formation tectonically contacts with very similar non-calcareous spotted shale of the Wronine Formation. Its age, based on infrequent dinoflagellate cysts is Aptian-Albian. Similar, Lower Aptian age was concluded for the Kapusnica Formation. Late Barremian-earliest Aptian dinoflagellate cysts have been found in the underlying topmost part of the Pieniny Limestone Formation.