VARIABILITY OF SHELL IN GASTROPODS OF THE GENUS BORYSTHENIA LINDHOLM, 1914: TESTING THE STATISTICAL APPROACH IN SEARCH OF TRAITS FOR THE RECENT AND FOSSIL SPECIES DELIMITATION

The gastropod mollusc genus Borysthenia Lindholm, 1914 comprises many species throughout Europe, Asia, North Africa and North America but species delimitation, based mainly on shell morphology (only possible concerning the fossil records) is often disputable. Statistical methods used to test if the shell measurements are reliable traits in delimitation of recent and fossil species in gastropod molluscs of the genus Borysthenia. Our analyses based on quantitative study of over 100 specimens of the Borysthenia species both modern and fossil. It is concluded that the dimensional characteristics of their shell are suitable for the differentiation of both recent and fossil (at least of Pontian age) species through the statistical processing of quantitative data. Through the morphological study of type material, taxonomic status of B. jalpuchense Gozhik, 2002 and B. vinogradovkaense Gozhik, 2002 described from the middle-pontian deposits of Ukraine revised. It is suggested that these taxa are considered two distinct though close relative extinct species. Stratigraphic range of B. jalpuchense is expanded up to the Lower Pontian. All the modern individuals of Borysthenia involved are attributed to B. menkeana (Jelski, 1863) due to their exact correspondence to the lectotype of this species.

ON THE POSITION OF THE BOUNDARY BETWEEN THE MOSCOVIAN AND KASIMOVIAN GLOBAL STAGES OF THE CARBONIFEROUS IN THE DONETS BASIN

Detailed new data on paleontology and stratigraphy were obtained in the process of fulfilling the tasks of the International Carboniferous Subcommission on definition of the scopes of the Moscovian and Kasimovian global stages and the precise position of the boundary between them. The analysis of these data has shown that the position of this boundary in the type area and in the other regions needs the revision. Recently the investigation of the conodonts from the Moscovian–Kasimovian boundary deposits in the Donets Basin revealed that the boundary between the Moscovian and Kasimovian stages in the official Ukrainian Carboniferous Stratigraphic Scheme does not correspond to this boundary in the type area of these stages in the Moscow Basin. To correct this situation the lower boundary of the Kasimovian in the Ukrainian Scheme must be downgraded by two conodont zones — Swadelina subexcelsa and Sw. makhlinae. To update this boundary in the type area to fulfill the task of the Carboniferous Subcommission four conodont species were proposed as potential index-species for the definition of the boundary between the Moscovian and Kasimovian global stages. These conodont species are as follows Sw. subexcelsa, Idiognathodus sagittalis, I. turbatus and I. heckeli. One of these species, which is selected, will be used as a marker of the studied boundary. None of these species is officially selected as a marker. If Sw. subexcelsa will be selected, the position of the Moscovian–Kasimovian boundary will remain at the present position. In this case this boundary in the Donets Basin has to be downgraded by two conodont zones. If one of three Idiognathodus will be selected, this boundary in the type area will be upgraded by one and a half regional substage. In the Donets Basin it will be upgraded by less than a cycle. Keywords: Carboniferous, stratigraphy, conodonts, extinction event, index-­species.

COOPERATION BETWEEN ACADEMICIAN OF NAS OF UKRAINE PETRO GOZHYK AND THE PROFESSIONAL PUBLIC

Academician of the National Academy of Sciences of Ukraine Petro Feodosiyovych Gozhyk, as the director of the Institute ofGeological Sciences of NAS of Ukraine, worked closely with professional public organizations, in particular with the PO «Unionof Drillers of Ukraine» and the PO «Union of Geologists of Ukraine». This paper highlights important activities initiated by publicorganizations, which were carried out with his active support and direct participation. Among such events: «Round Table todiscuss the Concept of efficient use of renewable deep hydrocarbon resources»; the Olevsk scientific and practical conferenceswere important for the geological community: «History of discovery and study of the Perga beryllium deposit as a world exclusive»,dedicated to the 60th anniversary of exploration works at the Perga ore field; «State and prospects of development of the Pergaore district». Each of these events has become a significant contribution not only to the development of the mineral resourcebase, but also to address legislative gaps in the extractive industry, promoting the development of public institutions.

MAIN STAGES OF DEVELOPMENT OF THE LATE CARBONIFEROUS FLORA AND VEGETATION IN THE DONETS BASIN AS THE BASIS OF JUSTIFICATION OF REGIONAL STRATIGRAPHIC UNITS AT THE PALAEOECOSYSTEM LEVEL

Four stages of development of the late Carboniferous vegetation cover have been established that correspond to the time intervals of four regional subdivisions of the Donets Basin − the Toretsian and Kalynovian Regional Stages, the Luganskian and Vyskrivskian Horizons of the Myronivskian Regional Stage. The analysis of phytostratigraphic and paleophytocenological data showed that the stages of vegetation development are characterized by the dominant plant communities in rank of orders of widespread landscapes. Сhanges from one stage to another are considered as the paleophytocenotic events, which are expressed by the changes of dominant communities of certain landscape types. The levels of paleophytocenotic events coincid with the bases of regional subdivisions The bases of the Toretsian and Kalynovian correspond to the levels of paleophytocenotic events, which were manifested by the formation of new communities types as a result of the evolutionary renewal of composition of wetland calamitean-fern and fern-pteridosperm forests of coastal lowlands as well as lycopsid and calamitean-fern forests of deltaic plains. The base of the Myronivskian (Luganskian Horizon) corresponds to the level of the paleophytocenotic event that was expressed by, firstly, the appearance of new communities types of seasonally dry pteridosperm woodlands of river valleys as a result of the evolutionary renewal of their composition, secondly, the appearance of new communities types of wetland calamitean-fern woodlands of coastal lowlands and calamitean-fern and pteridosperm woodlands of deltaic plains, the formation of which were due to the reduction of species compositions and the changes of dominants. The lower boundary of the Vyskrivskian Horizon corresponds to the level of the paleophytocenotic event that was expressed by the appearance of new communities types of wetland calamitean-fern and fern-pteridosperm woodlands of coastal lowlands and seasonally dry fern-pteridosperm woodlands of lacustrine-lagoon plains, the formation of which were associated with plant migrations and the appearance of new dominants. The considered paleophytocenotic events are manifestations of phytocoenogenetic processes, which led to paleophytocenotic changes, and mark main palaeoecosystem transformations in view of vegetation development stages.

FEATURES OF THE DEPOSITS OF THE LOWER DEVONIAN RED-COLOUR-TERRIGENIOS FORMATION OF THE LVIV PALEOZOIC DEPRESSION

Sediments of the Lower Devonian continental red-terrigenous formation of the Dniester series of the Lviv Paleozoic troughwere formed in the alluvial facies environment mainly in the oxidizing medium (they have a red color), and some of them are inthe restorative (gray color of the sediments). In the process of formation and existence, sedimentary formations of the LowerDevonian continental red-terrigenous formation underwent a number of successive stages of lithogenesis: sedimentary, diaand catagenesis and were significantly influenced by glazing processes at the stage of diagenesis. The authors investigatedthe catagenetic transformations of sandstones, siltstones, argillites, rocks of mixed composition of different facies (channel,riparian and floodplain facies conditions) taking into account geochemical (both oxidative and reductive) conditions of formation.A high degree of catagenetic transformations (up to the stage of late catagenesis) of rocks has been established. It was foundthat the nature and intensity of catagenetic transformations not only of different petrotypes, but also of the same type of rocksof different facial affiliation differ significantly, even if they are at the same stratigraphic level. It is established that the degreeof catagenetic transformations of sediments depends on their structural and textural features, material composition and facialaffiliation

ANTARCTIC RESEARCH – THE STATE PROGRAM OF UKRAINE

The article is dedicated to the memory of Academician Pеtrо Feodosiyovych Gozhyk (1937–2020) – Director of the Institute of Geological Sciences of the National Academy of Sciences of Ukraine and the first head of the State Program of Ukraine for Antarctic Research on the basis of the Ukrainian Antarctic Station “Academician Vernadsky”. More than 10 institutes and organizations of Ukraine have been carrying out a wide range of research for over 20 years: marine and coastal geological and geophysical work, continuous observations of the atmosphere, the ozone layer, ultra-long-range propagation of short-wave radiation. Biological research is being carried out with the prospect of realizing the resistance of living organisms in the harsh conditions of Antarctica for our latitudes. All our activities in Antarctica are carried out within the framework of international programs. By entering into international cooperation, Ukraine has shown a decent level of work and, at the same time, has taken obligations to the International Community. It is this approach to activities in Antarctica from the part of Ukraine that Petr Feodosievich tried to provide. We, the staff of the institute headed by him, deeply grieve over his untimely death and are trying to continue the worthy level of research that Academician of NAS of Ukraine Petro Feodosiyovych Gozhyk laid down.

PETRO FEODOSIIOVYCH GOZHYK: OCEANIC, MARINE AND ANTARCTIC RESEARCH

The article provides a brief overview of the publications, as well as our own memories about the doctor of geological and mineral sciences, Academician Petro Feodosiiovych Gozhyk — scientist, researcher that had state- and strategic level thinking, about his contribution to the development of marine geological works in the Institute of Geological Sciences of the National Academy of Sciences of Ukraine, his role in the creation of the Ukrainian Antarctic Center (nowadays the National Antarctic Research Center of The National Academy of Sciences of Ukraine) and the importance of his personality for the formation of Ukraine as «Antarctic State». P.F. Gozhyk was not only one of the initiators of the Center for Antarctic Research of the National Academy of Sciences of Ukraine, but also its first director, the developer of long-term polar research programs at the station «Academician Vernadsky». His scientific interests were focused on a wide range of subjects, and marine geology was among his scientific priorities. Academician P. F. Gozhyk was an organizer and participant of many round-the-world sea and ocean expeditions to the Indian, Atlantic and Southern oceans, the Red and Black Seas. The main publications of P. F. Gozhyk on «geology of the seas and oceans» and «geological studies of Antarctica» are listed in the article.