Creation of Geological 3D-Model of Komyshnianske Field Based on the Sequence Stratigraphy Principles

Currently, the sequence-stratigraphic section dismemberment is only being implemented in Ukraine, so this article is highly relevant. The authors created geological 3D model of Komyshnianske gas condensate field based on sequence-stratigraphic section dismemberment for the first time at this area. This approach is effective for the following conditions:-insufficient field geological study;-thickness of productive horizons does not reach the seismic resolution boundaries;-no significant difference in impedance values on reflection horizons. The selected technique includes the following stages:-field geological study, facies analysis (integration of well geophysical complexes, cores);-deduction and correlation of sequence boundaries;-construction of discrete log, which corresponds to specific sequences distribution;-conducting seismic interpretation of the 3D seismic survey study of research area;-construction of a structural framework with the involvement of correlated sequences boundaries;-comparison of volume seismic attributes with selected sequences distribution. A geological 3D model of Komyshnianske gas condensate field was created based on sequence-stratigraphic principles. During the research, a geological structure of field was analyzed, the separated conditions of sedimentation (sequences) were deducted and interpreted. During the seismic interpretation of 3D seismic survey of study area, local features of wave field were identified, their reflection in the core material was found and linked to the concept of changing sedimentation conditions. With a general understanding of the material transportation and accommodation direction, used method allows to qualitatively outline the distribution boundaries of sedimentation certain conditions and predict their development outside the study area. Construction of facies discrete log and their distribution in the seismic field allows grouping thin bed layers of collectors to reach the seismic resolution and use them to predict the distribution of facies associated with changes in the rocks reservoir properties (tracking beach facies of deltas/avandeltas, sloping sediments, etc.). The constructed model could be used as a trend for reservoir distribution at the stage of construction of static geological model. Involvement of sequence-stratigraphy technique is new approach to sedimentation conditions study within Dnipro-Donetsk depression (DDD) areas. The paper shows that provided methodology gives:-improved geological understanding of field through sedimentation analysis and facies logging;-trends for reservoir properties distribution with the involvement of construction facies volumes;-proposals for further field E&D. The general provisions under conditions of geological materials sufficient base can be applied to other DDD areas, especially in pre-border zones. Involvement of sequence-stratigraphy technique is new approach for sedimentation conditions study within Dnipro-Donetsk depression (DDD) area. On the example of Komyshnianske gas condensate field, the article shows that provided methodology gives:-improved geological understanding of field through sedimentation analysis and facies logging;-trends for reservoir properties propagation with the involvement of seismic volume studies;-propositions for further field Exploration & Development.

Soils of mountain floodplains in the zone of tectonic joints of Mongol-Okhotsk Orogenic Belt (Mongolia)

New data on the soils of mountain floodplains in the tectonic joints zone of the Mongol-Okhotsk Orogenic Belt on the example of the Upper Kerulen Basin are presented. Soil diversity is mostly determined by sedimentation conditions and drainage of the parent rocks. There are alluvial–humus (Fluvisol (Humic)), mucky–humus (Folic Fluvisol), dark–humus (Fluvisol (Mollic)), dark–humus gley (Gleyic Fluvisol) and dark–humus saline soils (Sodic Gleyic Fluvisol (Mollic)) were diagnosed. Tectonic movements of the earth’s crust lead to the appearance of shaftlike linear dams, blocking river flow through the valley. So, the Kerulen river changed the direction of the channel and go beyond the depression, embedding into its mountain frame. Current seismicity impact on soils appears locally at tectonically active positions of epigenetic areas, close to outputs of saline underground deep waters, in the form of surface soil salinity and hydrometamorphism.

A First Approach to a Quaternary Geomorphological Map of the German Seas

Our publication presents the first draft of a geomorphological map of the German North Sea and Baltic Sea. The inspiration for this map comes from the international collaboration of marine researchers within the European EMODnet Geology Project (https://www.emodnet-geology.eu/).The current climate change intensifies the natural processes of change in nature. Within the framework of various nature conservation projects, the importance of marine sediment structures on marine fauna and their reproductive cycles, sedimentation conditions, currents, etc. has been investigated. In order to be able to make statements for the German seas and document changes, the current state must first be recorded.

LITHOLOGICAL AND FACIAL FEATURES, COMPOSITION, AND SEDIMENTATION CONDITIONS OF TERRIGENOUS-CARBONATE ROCKS OF THE MOTY GROUP (SHAMAN CLIFF, IRKUTSK REGION)

We have studied terrigenous-carbonate rocks in the area near the Sayan mountains in the Irkutsk Region (Russia), specifically at the Shaman Cliff, being the stratotype area of rocks that belong to the Moty group. The cliff’s lower part is composed of sandstones, which fragments gradually decrease in size upward the cross-section. The middle and upper parts are composed of sandy dolomites and dolomites, respectively. In terms of material characteristics, the terrigenous rocks correspond to arkoses. According to the genetic typification, the arkoses are composed of destructed primary igneous rocks. The terrigenous-carbonate rocks contain a carbonate component that gradually increases in the upper part of the cross-section. In the Shaman Cliff cross-section, we distinguish 32 lithological units and eight lithologicalgenetic types of deposits. Paleogeodynamic conditions are reconstructed for the formation of the sedimentation basin. Our study of the Shaman formation reveals specific features of the lithological facies, which suggest that these rocks accumulated in a coastal environment affected by tides. In the study area, clastic materials were mainly removed from an orogen that formed due to the Vendian accretion-collision events in the southern folded frame of the Siberian platform. Dolomites composing the upper part of the cliff are attributed to the Irkutsk formation of the Moty group. Their lithological features give evidence of shallow-marine conditions of their formation, without any supply of clastic material, which contributed to mass dispersal of the Cambrian biota described in [Marusin et al., 2021]. It is our first initiative to draw a boundary between the Shaman and Irkutsk formations of the Moty Group along the base of the carbonate eluvial breccia unit that marks the stratigraphic break. In the cross-section, this boundary represents the border between the Upper Vendian and Lower Cambrian.Our conclusions are generally consistent with the ideas of most researchers about the Late Vendian evolution of the southern margin of the Siberian platform. The results of our study can be used in further investigation of this area and provide a basis for correlating the studied strata with the same-age reference cross-sections of other regions in Siberia.

Diatoms and aquatic palynomorphs in the Barents sea sediments: main distribution patterns and use in palaeoceanological studies

The Chapter deals with the uniqueness of the Barents Sea and adjacent sea areas from the viewpoint of the main groups of phytoplankton (diatom algae and dinoflagellate) development and their reflection in tanatocenoses of bottom sediments. Special attention is paid to the distribution of microfossils in surface waters as an indicator of the modern sea ice and hydrological signal. A distinctive feature of the Barents Sea tanatocenoses is the frequency of re-deposited Paleogene and Cretaceous forms of diatoms and dinocysts. Despite all the difficulties in finding microfossils in bottom sediments, data were obtained on characteristic associations mainly related to the redistribution of relatively warm North Atlantic waters. The issues of microfossils in cores and boreholes located on the Barents Sea shelf and continental slope are considered and the most extensive material on changes in sedimentation conditions in the Pleistocene and Holocene is generalized.

Practical Application of the Mineralogical Mapping Method for Stratigraphy of the Cretaceous Deposits of Southern Primorye (Russian Far East)

Highly ordered mixed-layer formations of chlorite–smectite (corrensite) and mica–smectite (rectorite) were found in the volcanogenic–sedimentary rocks of Southern Primorye. They have shown a rather narrow “living” time interval (Cretaceous–Paleogene). The associations of corrensite and rectorite with chlorite, mica, kaolinite, and laumontite have great value in labeling. Their study would determine the time and thickness parameters of sedimentation conditions, the nature of the transformation stages, the physicochemical and climatic parameters of the accumulation of the depositional material, and the geological history and stratigraphic construction of Mesozoic–Cenozoic volcanogenic–sedimentary rocks of the Primorye Region.

Kimmeridgian–Volgian ostracods of Samarskaya Luka: Paleoecological analysis and reflection of sedimentation conditions in rock magnetism

The analysis of the distribution of the Kimmeridgian–Volgian ostracods in the section near the village Valy made it possible to establish a sequence of eight communities, the change of which reflects changes in the ecological conditions in the basin. Changes in sea level fluctuations, the main physical and chemical parameters of the ostracod habitat – temperature, salinity of water, oxygen content in it, eutrophy and concentration of organic matter in sediment – are reconstructed. Information on the magnetic susceptibility and its increase after heating was obtained. Statistically significant relationships between the petromagnetic characteristics and some conditions of sedimentation were established. The conclusion about the relevance of continuing such studies at objects of different ages and genesis was made.

FEATURES OF THE FORMATION OF THE LOWER-MIDDLE CAMBRIAN DEPOSITS IN CONNECTION WITH THE ASSESSMENT OF OIL AND GAS POTENTIAL IN THE TERRITORY OF THE NORTH-TUNGUSKA OGA

The key features of the structure, lithology and sedimentation conditions of the Lower and Middle Cambrian of the North Tunguska OGO are considered. A seismogeological model of the section in the zone of its facies replacement was compiled. A description of two paleogeographic schemes of the Toyon and May centuries is given. The high prospects for the oil and gas content of this territory have been substantiated.

THE STRUCTURE, COMPOSITION AND DEPOSITIONAL ENVIRONMENTS OF KUONAMKA FORMATION IN THE EAST OF ANABAR OIL-AND-GAS REGION

The structural features, lithological composition and sedimentation conditions of the Kuonamka Formation were identified in the analysis of core material uncovered by wells in the east of Anabar oil-and-gas region in the basin of the Kyulenke River. It was established that the studied highly carbonaceous rocks accumulated in deep-water conditions of the open sea in reducing, mainly euxinic environments.