Pages: 23 - 40
Authors: LILIAN SVABENICKA
Abstract: A joint occurrence of high-latitude "boreal" and low-latitude "tethyan" calcareous nannofossil taxa has been observed in sediments of Late Campanian and Late Maastrichtian age, in the Outer (Menilite-Krosno) group of nappes (Waschberg Zone and Zdanice Unit) and Magura group of nappes (Raca and Bile Karpaty units) of the Outer Western Carpathians. The degree of influence of the "boreal" province was a function of the paleogeographical position of basins and geological time: the depositional area of the Outer (Menilite-Krosno) group of nappes was probably situated on the SE passive margin of the West European Platform. The calcareous nannofossils include both high-latitude species (Monomarginatus quaternarius, Neocrepidolithus watkinsii) and low-latitude ones (genera Ceratolithoides and Quadrum) in Late Campanian times. In Maastrichtian times the high-latitude phenomena dominates (common Psyktosphaera firthii, absence of Ceratolithoides kamptneri, Watznaueria: Micula ratio = 1:3). In the Magura group of nappes the depositional area of which is considered to be a high activity terrane of the Tethyan mobile Realm, the Late Campanian nannoflora is characterized by the presence of low-latitude species. The influx of high-latitude species is evident here especially in the Late Maastrichtian (higher numbers of Prediscosphaera stoveri and Nephrolithus frequens). A migration path can be supposed between the northern part of the Tethys and North European basins through the Peri-Tethyan basins (Polish Trough). In contrast, the Late Campanian section of the Münsterland Basin, which is included into the "boreal" province, yielded exclusively cosmopolitan and boreal nannofossils including Heteromarginatus bugensis.
Keywords: Outer Western Carpathians, Munsterland Basin, Campanian, Maastrichtian, calcareous nannofossils, biostratigraphy, bioprovincesDownload PDF document Show Text Version