FORAMINIFERA AND BIOSTRATIGRAPHY OF THE YPRESIAN STAGE (LOWER EOCENE) IN WESTERN SIBERIA

V. M. Podobina

The paper summarises the data on foraminifera of the Ypresian stage (Lower Eocene) in West Siberia. The Textularia sibirica, Anomalinoides ypresiensis ovatus assemblage identified by the author is widespread and consists of agglutinate and secretion calcareous species. The latter are similar to the analogous species of the Ypresian stage in Netherlands. The strata hosting the assemblage are designated one microfaunal zone within the upper Lower Lyulinvor Subformation (Lyulinvor Formation and Horizon). Within the stratotype zone (Kaymysovsky dome, middle meridional course of the Vasyugan River, Western party) the hosting rocks are gray or light gray often opoka-like clays. Three paleontological tables show figures of major species of the Ypresian stage in West Siberia.

Key words: foraminifera, Ypresian stage, West Siberia.

DOI 10.20403/2078-0575-2016-3-3-10