Department of geochemistry of sedimentary series of oil- and gas-bearing provinces

The head of the department  - PhD in Geology Anatoliy R. Galamay The department was created in 1969 under the name "Department of salt structures of oil and gas-bearing regions". The Corresponding member of the National Academy of Sciences of Ukraine Vasyl I. Kityk was appointed the first head of the department. Doctor of Geological and Mineralogical Sciences, Professor Oleg Y. Petrychenko was headed the department from 1984 to 2007. The duties of the head of the unit from 2007 to 2015 were performed by the PhD in Geological and Mineralogical Sciences Igor V. Dudok, and since 2015 was the PhD in Geology Sergiy V. Vovnyuk. Since 2019, the department has been headed by the PhD in Geology Anatoliy R. Galamay. The main areas of research of the department: – geology and geochemistry of evaporite formations of Ukraine and the world and associated deposits of gypsum, rock salt, potash salt, native sulfur, celestine; – evolution of the chemical composition of sea water in the Phanerozoic based on the results of a complex thermobarogeochemical study of fluid inclusions in halite of marine evaporite formations; – development of measures to solve technogenic and ecological problems that arose as a result of the unplanned shutdown of former domestic potash productions, which will allow both to rehabilitate the territories and to attract the attention of domestic and foreign investors to the strategically important resource potential of Ukraine. The world-renowned scientific thermobarogeochemical school of evaporite studies, formed in previous years, is actively developing in the department, and world-class fundamental and applied achievements in the field of geochemistry and thermobarometry of mineral-forming solutions are being made. The chemical composition of brines of fluid inclusions in salts is determined by a unique ultramicrochemical (UMСA) method developed in the late 60s of the 20th century at the Institute of Geology and Geochemistry of Combustible Minerals of the National Academy of Sciences of Ukraine by Prof. Oleg Y. Petrichenko. Despite the fact that in the following decades, other methods of microanalysis of inclusion brines were invented in the world (Extraction-IC, Cryo-SEM-EDS, ЕСEM-EDS, LA-ICP-MS), due to the simplicity of methodological operations, good reproducibility of measurement results, with the possibility of microanalysis of brines with a volume of up to 0.00006 mm³, UMСA is currently leading among other methods for determining the quantitative chemical composition of inclusions brine in salts. Accumulation of significant actual material obtained from inclusions in halite allowed to distinguish global age fluctuations in the chemical composition of sea water (from sulfate to chlorcalcium type) during the last 545 million years. The limits of fluctuations in the chemical sea water composition are refined from year to year based on the results of the study of previously unexplored salt basins. Mineralogical and geochemical research is aimed at a comprehensive study of the salt formation problems, such as the physical and chemical parameters of the sedimentation environment and recrystallization of salts, questions of the evolution of the sea water composition, as components of the general historical development of the Earth. Using a complex of methods: thermobarogeochemical (ultramicrochemical, thermometric, barometric), mineralogical-petrographic, isotopic, electron-microscopic, chemical, X-ray spectral, X-ray diffractometric and other methods, criteria for searching for minerals associated with evaporites (primarily oil, gas, trace elements, valuable forms of complex sulfate potassium-magnesium salts for the production of fertilizers). Among the achievements of scientists of the department in recent years, the following should be mentioned: The chemical composition of Ordovician Sea water was established for the first time. Conducted ultramicrochemical studies and analysis of previously published actual material on evaporites of the Lower Paleozoic indicate a lower magnesium content in the brines of the Lower Paleozoic basins than in the corresponding concentration modern seawater, and a higher potassium content than in the basins brin of the later periods; Based on the results of the study of primary single-phase fluid inclusions in halite, the reconstruction of the Permian paleoclimate of the Perdural region, the Neogene of the Carpathian region at the Mi3b stage, the Messinian of the Mediterranean, as well as models of solerod basins were constructed, which resolves some controversial issues of the tectonic features of the structure of ancient continental margins as a whole and sedimentation in salt-bearing basins in particular; It was established that the distribution of high-magnesium clay minerals in Phanerozoic marine evaporites correlates with age-related changes in the sea water composition. Magnesium minerals are confined to the stages of its sulfate type, which is one of the confirmations of the interconnection of geological processes of the Earth's evolution; For the first time, fluid inclusions with microdroplets of hydrocarbons were established in the halite of various evaporite formations of the world. Thermobarogeochemical studies, in particular in the Carpathian region, established that low temperature at the stage of the post-sedimentation stage of salt formation, high mineralization and mainly Na–K–Mg–Cl–SO₄ type of pore brines did not contribute to thermolysis of dispersed organic matter in kerogen towards oil formation. Therefore, fluid inclusions with liquid explosives and cracks in halite, filled with oil, established in salts in a number of areas of the Carpathian oil and gas-bearing province, are geochemical halos of dispersion of explosive accumulations and indicators of the presence of hydrocarbon deposits or oil and gas shows in the underlying sediments; The identification of signs of oil and gas saturation of the subsurface (fields of abnormal hydrocarbon concentrations) in near-surface sediments made it possible to outline the priority areas of their potential accumulation. The nature of the distribution of hydrocarbon components is determined by the structural features of the structure of the sites, in particular the form of deposition of halogen deposits, and indicates the determining role of the tectonic factor in the formation of concentration fields of migrant gases. To solve the actual scientific and practical tasks of finding minerals related to salt-bearing formations, scientific and technical cooperation is currently being carried out with scientific research organizations, geological institutions of Ukraine and foreign countries: State Research and Design Institute of Basic Chemistry (Kharkov), scientists from Poland (Akademia Gόrniczo-Hutnicza, Krakόw), Turkey (Department of Geological Engineering, Engineering and Natural Sciences Faculty, Konya Technical University, Konya, Türkiye), China (Nanjing Institute of Geology and Paleontology, Chinese Academy of Sciences). The department has 11 employees, among them 5 candidates of sciences. The department operates two certified laboratories: X-ray analysis and analytical methods of analysis.