The results of a comprehensive study of the Lower–Upper Ypresian boundary sediments at the Suvlu-Kaya Mountain section (Bakhchisarai region, Southwestern Crimea) are presented. The evolution of formation of the nummulitic bank in the study area is shown based on a detailed microfacies analysis. The sediments were formed on a deep shelf with depths at and below the storm wave base. It has been established that the Ypresian transgression was developed gradually, in three stages, with the maximum at the end of the Early Ypresian, and then was followed by a long-term regression. The data are confirmed by the results of the micropaleontological analysis of the morphogroups.

В 2022 и 2023 годах вблизи Беломорской биологической станции имени Н.А. Перцова в акватории Кандалакшского залива проведены детальные магнитометрические работы. Магнитометрическая съемка 2023 года выполнена с использованием нового отечественного магнитометра-градиентометра MariMag 300m, обеспечившего определение аномалий магнитного поля со среднеквадратической погрешностью ±1 нТл. Геологический анализ аномального магнитного поля, поддержанный количественными расчетами модели объемного распределения намагниченности, позволил выявить новые линеаменты, природа которых может быть связана с повышенной намагниченностью пород вдоль разломов северо-западного простирания; в Нильма-Чернореченской акватории скорректировать границу формаций фундамента, выделить неизвестные ранее габброидные массивы и связать высокочастотные аномалии магнитного поля с аллювиальными отложениями в подводных руслах рек Черная и Нильма. Detailed magnetic surveys were carried out near the White Sea Biological Station named by A.N. Pertsov in the waters of Kandalaksha Gulf in 2022 and 2023. The magnetic survey of 2023 was carried out by using a new Russian magnetometer-gradiometer «MariMag 300m» which provided the determination of magnetic field anomalies with a standard error of ±1 nT. The geological analysis of the anomalous magnetic field, supported by quantitative calculations of the 3D magnetization model, made it possible to identify new lineaments, the nature of which may be associated with increased magnetization of rocks along the faults of the northwestern stretch; to correct the boundary of the basement formations in the Nilma-Chernorechenskaya water area, to identify gabbroidal bodies which, were previously unknown, and to associate high-frequency magnetic field anomalies with alluvial deposits in the underwater riverbeds of the Chernaya and Nilma rivers.

Fracture modeling in the section of Suvlu-Kaya Mountain, South-West Crimea, was made. A three-dimensional geological model of the section was constructed, geomechanical modeling was performed, and stress fields in the three-dimensional geological structure were calculated. The modeling results were compared with real measurements of fracturing in the field.

The nature of Cretaceous-Eocene boundary is one of the outstanding questions of Crimea Geology. The new data are presented to show that the Cretaceous-Eocene boundary can be established in the Central Crimea very accurately by using the method of quantitative genetic analyses including the Isotope Geochemistry. Integrated lithostratigraphic investigations and Isotope composition of Carbon/Oxygen were conducted on the Cretaceous -Eocene section of the western slope of Ak-Kaya mount (Belogorsk, Crimea). Four layers of different types of rocks were investigated, where the layer 1 and 2 belong to the Maastrichtian, 3 and 4 to the Eocene.The top of the Maastrichtian layer is characterized by a differently oriented fracture system, including large paleoseismic dislocations or a seismogenic trench. The fracture networks are connected and filled with material similar to the Eocene basal horizon including fragments of various sizes of Maastrichtian rocks.Five microfacial types of the collected rock samples were distinguished as a result of microscopic examination. Also X-ray phase analysis, δ13С and δ18О isotopic analysis and X-ray fluorescence analysis were made to specify and compare the mineral composition of Maastrichtian and Eocene rocks. These analyzes allowed to specify paleogeographic conditions. In addition, measurements of fractures in the Cretaceous–Eocene boundary deposits were made to determine the stages of deformation of the whole structure.As a result of the research, it was obtained:1) throughout the entire studied geological interval, sedimentation occurred in a shallow sea of normal salinity. However, conditions were probably more humid in the Eocene, based on lower salinity values.2) Three major stages of deformation were identified: pre-Eocene, Eocene, and post-Eocene.3) The average temperature of the formation of Maastrichtian rocks is 19-22°C, and Eocene rocks is 24-27°C. The increase in temperature up to 38°C during the formation of the Eocene basal horizon may be associated with the global climatic event EECO (Early Eocene Climate Optimum). The synchronicity of the formation of steep submeridional fractures and the basal horizon of the Eocene has been proved. It is shown that the Eocene deformation stage corresponds to the formation of paleoseismic dislocations during the main phase of tectonic activity in the Pontids (Eastern Turkey).

Paleotemperature curves for water masses and average annual temperatures were constructed from our own and published data for Central and Eastern Tethys for the Jurassic-Quaternaryfor the first time.

The paleotemperature curves for water masses and average annual temperatures have been plotted for the first time on the basis of original and published data for the Central and Eastern Tethys for the Jurassic–Quaternary period.

В учебном пособии рассматриваются наиболее важные аспекты полевых методов геологических исследований на примере Бахчисарайского района Крыма. Для студентов геологического факультета МГУ им. М.В. Ломоносова, а также всех специалистов и студентов-геологов, использующих в работе полевые методы геологических исследований

Information on the structure features as well as new data on the distribution of calcareous nanoplankton (NP) from the Cretaceous-Paleogene boundary deposits of the Central Crimea is given. There is a rich complex of Cretaceous NP in both Maastrichtian and Danian rocks. Danian NP is sparse, poor preserved or absent. Lower Maastrichtian species Tranolithus orionatus (=Tranolithus phacelosus Stover) unknown in the Upper Maastricht of European sections and described only from the Upper Maastricht of the South-West of Tunisia is noted in Upper Maastrichtian rocks of studied area. Zones NP2–NP4 were determined in Danian rocks. The question of paleogeography is also concerned.

The article considers features of boundary Cretaceous–Eocene deposits in Belogorskiy district of Central Crimea. Structures interpreted as paleoseismic dislocations are described, their age, features of composition, history of formation are specified, magnitude and intensity of paleoearthquake are estimated. Steeply dipping fractures in Cretaceous rocks are regular and associated with dip and strike of the main regional structures. Their formation was caused by a transverse stretching during the main uplift of the structures at the beginning of the Eocene coinciding with the main phase of folding in Northern Turkey.

The peculiarities of the structure of Cretaceous–Eocene boundary deposits in the Belogorsk district, Central Crimea, are considered. Tectonic structures interpreted as paleoseismodislocations are revealed and described; their age, structures, and evolutionary history are characterized; the magnitude and intensity of the seismic paleoevent are estimated. The position of steeply dipping fractures in Cretaceous rocks is regular and related to the bedding along the dip and strike of the structure. Their formation was caused by transverse extension in the background of general uplift at the beginning of Eocene, coincided in time with the main folding phase in North Turkey.

The nummulitic limestones of Crimea and the southwestern Caucasus, often interpreted as "nummulite banks", formed carbonate platforms throughout most of the Ypresian-Lutetian. Such deposits were accumulated in shallow warm-water basins of Crimea and the Caucasus, which differed from each other by the structure of the basement and the hydrodynamic regime. The Crimean carbonate platform was relatively flat and was formed mainly within quiet hydrodynamic conditions below the fair-weather wave base (less than 50 m). The facies changes within it reflect variations in water depth. Facies distinguished there form the nummulite bank, its lee-side slope, the shelf plain in the rear of the bank (back-bank), and the relatively deep basin-ward slope with predominantly terrigenous sedimentation (fore-bank). Among larger benthic foraminifera (LBF), Nummulites, Operculina, and Assilina are the most typical. Discocyclina is less common; its increase in abundance is interpreted as deepening of the basin. Nummulitic limestones and marls reappear in the southwestern Caucasus within the shallow-marine deposits of the Georgian massif shelf basin. It was bordered with the Great Caucasus deep-water flysch basin in the north and the rift-related volcanic area of the Achara-Trialeti in the south. Nummulitic limestones of the Bzyp and Kodori river valleys and the Novy Afon district formed the "nummulite banks" upon the local basement uplifts within the Georgian massif shelf basin. The main components among the LBF are Discocyclina, Nummulites, and Operculina; Assilina is absent.

A representative assemblage of diatoms and silicoflagellates found in a excellent state of preservation is described from terrigenous cherty deposits of the Upper Cretaceous, which are exposed in a quarry near the Kologrivovka village in Saratov Region. The assemblage is correlative with diatoms of the Costopyxis antiqua Zone of the lower Campanian and with silicoflagellates of the Cornua trifurcata Zone, the upper one in the lower Campanian. According to the taxonomic composition, dominated by diatom genera Cortinocornus, Costopyxis, Hemiaulus, Paralia, Pseudopodosira , and Stephanopyxis , the assemblage was typical of a highly productive neritic zone with an active hydrological regime. A perceptible content of silicoflagellates among the diatoms suggests the normal salinity of the sedimentation basin. The comparable sedimentation settings in marginal parts of the Early Campanian epicontinental basin on the south of the East European platform can also be inferred based on the data from the lithological analysis.

Из терригенно-кремнистых отложений верхнего мела, вскрытых карьером в районе с. Кологривовка Саратовской области, выделен уникальный по сохранности и представительности комплекс диатомовых и силикофлагеллат. Он соответствует комплексу зоны Сostopyxis antiqua по диатомеям нижнего кампана и комплексу зоны Cornua trifurcata по силикофлагеллатам (верхняя часть нижнего кампана), установленным ранее для аркто-бореальной области. Структура изученных комплексов с доминированием диатомовых Cortinocornus, Costopyxis, Hemiaulus, Paralia, Pseudopodosira, Stephanopyxis типична для высокопродуктивной неритической зоны с активным гидрологическим режимом. Заметное присутствие силикофлагеллат говорит об условиях нормальной солености бассейна. Сходные условия седиментации в краевой части внутриконтинентального бассейна южной части Восточно-Европейской платформы в раннекампанское время реконструируются и по данным литологического анализа.

This work considers the structure and conditions of the formation of deposits of the Simferopolskoe regional stage of the Crimea. The deposits of this stage include planktonic foraminifera zones Morozovella aragonensis and Acarinina bullbrooki and nanoplaktonic zones Marthasterites tribrachiatus (the upper part), Discoaster lodoensis, Discoaster sublodoensis (lower part). The deposits of this interval throughout most of the Crimea represent a nummulitic bank, which formed in shallow warm-water basin and was isolated carbonate platform. The distribution of rocks of this regional stage, the facial change, and a number of interruptions are shown in the chronostratigraphic profile. The facial transitions within the carbonate platform point to variations in the basin’s depth, as well as periodical changes in the relative sea level, which were not only of a eustatic nature, but were determined by the periodic rise of the Simferopol Uplift.

The Danian deposits of the Crimea are described. Emphasis is placed on the characteristics of the rock of a well-exposed section in the Crimean piedmont. The depositional environment and paleogeography of different sections of the Crimea are reconstructed. The sequences and the system tracts that are distinguished in the Danian deposits fix the alternation of transgressive-regressive episodes. It is revealed that the stratigraphic completeness of Danian sections and variations in their thickness are determined not only by the sea-level fluctuations, but also by the tectonic events that manifested themselves in the growth of the Simferopol’skoe rise and the formation of trough-like structures in eastern Crimea.