Dorotiak Y. Biostratigraphy of Upper Jurassic and Lower Cretaceous sediments (Oxfordian-Lower Berriasian) of the Mountain Crimea by foraminifera.

The dissertation on competition of a scientific degree of the candidate of geological sciences (doctor of philosophy) on a specialty 04.00.09 "Paleontology and stratigraphy" (103 Earth sciences).– Institute of Geological Sciences of the National Academy of Sciences of Ukraine, Kyiv, 2021. The dissertation is devoted to solving biostratigraphic problems based on the study of foraminifera from sections of the Upper Jurassic and Lower Cretaceous from different structural and facies zones of the Mountain Crimea, reproduction of their living conditions, as well as the study of boundary deposits of the Jurassic and Cretaceous systems. Based on the analysis of the systematic composition of foraminifera from the Upper Jurassic and Lower Cretaceous sediments, the stages of development of the microfauna of foraminifera have been established, and the features of foraminiferal groups have been determined. According to the results of microfaunistic studies of Upper Jurassic and Lower Cretaceous sediments, biostratigraphic subdivisions by foraminifera have been established and the paleontological characteristics of the Stratigraphic schemes of Mesozoic sediments of the Mountain Crimea have been supplemented. The similar age groups of foraminifera from the Upper Jurassic and Lower Cretaceous deposits of different structural-facies zones of the Mountain Crimea are compared. The biozonal correlation of local stratigraphic subdivisions was carried out:zones Lenticulina quenstedti Globuligerina oxfordiana (early Oxfordian), Lenticulina russiensis Epistomina uhligi (late Oxfordian), Anchispirocyclina lusitanica Melathrokerion spirialis (late Tithonian), Protopeneroplis ultragranulatus Siphoninella antique (early Berriasian) and layers of Epistomina praetatariensis Globu1igerina parva (early Kimmeridgrian) with the zones of the Pre-Carpathian and Pre-Dobrudzha depressions, the North Caucasus and the Eastern European platform.As a result, the Upper Jurassic and Lower Cretaceous deposits of the Mountain Crimea and adjacent regions were correlated: the Pre-Carpathian and Pre-Dobrudzha Depressions, the North Caucasus and the Eastern European Platform.