Tuzyak Y. Lower Cretaceous Foraminiferas and stratigraphy of the Crimea Plain.

The results of research of the systematic composition of Lower Cretaceous foraminifers from Plain Crimea are revealed in the thesis. There are 64 foraminifers species described monographically. They belong to 33 genera and 15 families. 24 species were recorded in the Ukraine and 54 species - in the Plain Crimea for the first time. Biostratigraphic subdivision of Lower Cretaceous of the Plain Crimea are realizated. Nine biostratons have been distinguished dy foraminifers (three zones and six layers with fauna). Each of them characterizes a separate stratigraphical range that permit to correlate them with other regions. An interregional correlative chart (the Atlantic, the Tethys and the Pacific regions) has been created. Global distribution stratons of Lower Cretaceous and changes fullness of stratigraphic succession, connections of sedimentation basins are traced, and local zonal scales are detailed. The operating chart of stratum division of Lower Cretaceous of Plain Crimea is improved. Description of paleogeography of Early Cretaceous basin is specified and time-histories are traced and for the areas of situations of sedimentation. It has been established that during the Early Cretaceous, accumulation of Lower Cretaceous sediments in the Plain Crimea occurred in the sublittoral zone of the sedimentation basin. It was characterized by constant changes of physical, chemical, biological and geographical factors that allowed us to distinguish two basins in its development - the Hauterivian-Early Aptian and the Middle Aptian-Albian. Key words: Foraminifers, Lower Cretaceous, Crimea Plain, stratigraphy, paleogeography, paleoecology.