DEEP WATER AGGLUTINATED FORAMINIFERA FROM THE JURASSIC/CRETACEOUS BOUNDARY AND PALEOENVIRONMENTAL SETTINGS OF THE MAIOLICA TYPE FACIES FROM THE CZORSTYN RIDGE (PIENINY KLIPPEN BELT, WESTERN CARPATHIANS)

摘要

Deep-water carbonates deposited on the Czorstyn elevated ridge of the Pieniny Klippen Belt paleogeographic domain record changes in agglutinated foraminifera morphogroups through the J/K boundary interval at the Erdutsky kostol section. Microfacies, abundance, taxonomic and morphogroup analyses of the agglutinated foraminifera show the response of the assemblages to the flux of organic matter. In the uppermost Tithonian C. brevis Zone a distinct high abundance assemblage is represented mostly by sessile epifaunal tubular agglutinated foraminifera such as Rhizammina and Tolypammina, pointing to an eutrophic setting. In the lowermost Berriasian C. alpina Zone the mobile epifaunal tubulothalamous taxa Ammodiscus and Glomospira and multilocular taxa Cribrostomoides and Trochammina increase while the epifaunal tubular agglutinated foraminifera decrease. The assemblage composition and the slender tubular foraminifera suggest oligotrophic settings. The infaunal foraminifera decrease and point to increasing oxygenation of the bottom and pore waters.