Open AccessSVRCHNOKŘÍDOVÁ FAUNA (FORAMINIFERA, BIVALVIA) PODSLEZSKÉ JEDNOTKY Z POTOKA KOPYTNÁ V BYSTŘICI NAD OLŠÍ
Author(s) -
Miroslav Bubík
Publication year - 2016
Publication title -
geologické výzkumy na moravě a ve slezsku v roce .../geologické výzkumy na moravě a ve slezsku v roce ...
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.128
H-Index - 1
eISSN - 2336-4378
pISSN - 1212-6209
DOI - 10.5817/gvms2016-1-2-45
Subject(s) - cenomanian , foraminifera , geology , paleontology , benthic zone , biostratigraphy , marl , cretaceous , bathyal zone , oceanography , structural basin
Recently, Late Cretaceous strata ranging from the Cenomanian to the late Maastrichtian were found in the Subsilesian Unit of Moravian Carpathians. The stratigraphic assignment is based upon planktonic and benthic foraminifer biostratigraphy. Planktonic foraminifer markers: Marginotruncana pseudolinneiana Pess., Globotruncanella petaloidea (Gand.), Laeviheterohelix dentata (Sten.), Rugoglobigerina pennyi (Brön.) and benthic foraminifer markers: Plectorecurvoides irregularis Geroch, Bulbobaculites problematicus (Neagu), Uvigerinammina jankoi Majzon, Conotrochammina sp. etc. are briefly discussed and figured. In Campanian–Maastrichtian marls also articulated specimens of inoceramid bivalves Platyceramus sp. indeterminable to specific level were found. They are related to giant inoceramids known from the Coniacian–Campanian of the Euramerican biogeographical region and North Pacific Province. Folded inoceramid valves evidences slumping of sediment during the early diagenesis, prior to formation of carbonate concretions that include the shells. Both lithology and composition of foraminifer assemblages show trend from eutrophic black clays of the Cenomanian, through greenish silty clays of the Turonian–Coniacian, towards greygreen mottled and more oligotrophic variegated marls and clays of the Campanian–Maastrichtian. Cenomanian taphocoenosis consists of agglutinated taxa dominated by Rhizammina, Hyperammina, Kalamopsis and Adercotryma. Calcareous benthic foraminifers are extremely rare, planktonics are missing. Benthic foraminifer density (specimens per 1 g of rock) is about 9. Turonian–Coniacian taphocoenosis contains, besides agglutinated taxa, also some calcareous taxa including few planktonics. Campanian–Maastrichtian taphocoenoses comprise agglutinated and calcareous benthics indicating bathyal habitat (Marssonella, Spiroplectammina, Recurvoides, Gyroidinoides). Benthic foraminifer density reaches the value 643. At the same time the planktonic foraminifers represent 94 % of taphocoenosis.