TROVANTS OF THE LENA RIVER: HYPOTHESIS AND FORMATION MODEL

Unusual nodule formations have long been known in the steep banks of the Lena River and its tributaries. Their belonging to the category of Trovants (trovantogenesis) has been established. It is shown that trovants formation (trovantogenesis) is a process of specific transformation of cemented sands to varying degrees in platform and sub-platform environments. The hypothesis expressed by Romanian geologists about the pseudo-concretionary nature of the trovants has been confirmed. The aqua-dissipative model of their genesis is proposed. The variant of genetic сlassification of small geological bodies wherein trovants are classified as a consistent type is discussed.

TO THE 40TH ANNIVERSARY OF IPREK SB RAS

The article is devoted to the 40th anniversary of IPREK SB RAS. The history of the institute’s creation and tasks set for it by the Presidium of the Siberian Branch of the USSR Academy of Sciences are briefly described. Modern research directions are reflected in reports of the anniversary conference held in August-September 2021. The most striking results of world significance are presented, as well as the geography of applied environmental works performed in the Trans-Baikal Territory. The list of advanced research directions included in the plans of the Institute is given.

CAPITALIZATION OF MINERAL RESOURCES AS AN INNOVATION ECOLOGICAL STRATEGY

The paper presents issues of evaluation objects of subsoil usage and reflecting information of mineral assets for oil and gas companies. Estimation of the objects in the mineral resources sector is regulated by IFRS 6 «Exploration for and Evaluation of Mineral Resources», Russian Financial Standard, US GAAP and other normative documents. The authors` idea is to capitalize costs connected with the stages of geological exploration process, what is considered as an innovative component. Concepts of natural and environmental capital are overviewed. Different classifications of reserves and mineral resources of various categories of oil and gas are analyzed. The results of the study show that capitalizing reserves as mineral assets in oil and gas companies is possible and economically profitable.

PROBLEMS OF AGE AND GENETIC DIAGNOSTICS OF QUATERNARY DEPOSITS IN THE VALLEY OF THE YENISEI RIVER MIDDLE COURSE (YENISEI – LOWER ANGARA STRATIGRAPHIC REGION AND THE MINUSINSK BASINS AREA)

The article is devoted to the state of stratigraphic exploration maturity of the Eopleistocene – Neo-Рleistocene Quaternary deposits on the boundary of mountain and plain territories in the non-glacial area. The material analysis shows an inadequate rationale of the existing stratigraphic schemes, according to which the ladder of alluvial terraces of these territories was formed sequentially during the Eopleistocene, Neo-Pleistocene and Holocene. The revising of representative sections was carried out, the provision of them with geochronological data, the accuracy of age and genetic diagnostics were evaluated.

NEURAL NETWORK-BASED APPROACH TO RESISTIVITY LOGS EXPRESS SIMULATION IN REALISTIC MODELS OF COMPLEX TERRIGENOUS SEDIMENTS

The article proposes a new algorithmic approach to resistivity logs simulation based on convolutional neural networks wich allows constructing algorithms for solving forward problems for specific logging tools in detailed models of near-wellbore space with thin layers, accounting for radial resistivity changes, borehole wall irregularities and drilling fluid displacement by the logging tool. Experimental algorithms for expressmodeling for three common Russian galvanic and induсtion logging methods in two-dimensional models of the near-wellbore space have been implemented based on the proposed approach. Logs simulation using the developed neural network algorithms is multi pletimes faster than using numerical solvers. The proposed solutions open up possibilities to use more sophisticated basic geoelectric models of the near-wellbore space. The use of models adequate in complexity to the actual target geological objects will increase the reliability of interpretation results of resistivity logs measured in complex geological conditions.

GOSUDAREV LOG REFERENCE SECTION OF THE GELASIAN AND EOPLEISTOCENE

An integrated analysis of Quaternary deposits of the Gosudarev Log section near Krasnoyarsk was carried out. In the wall of the ancient ravine, deposits of the two highest river terraces of the Yenisei River embedded in accumulative formations of the so-called Batoisky uval [ridge] were uncovered. In the axial part of this ridge, lacustrine Eopleistocene formations overlie river gravel of the Gelasian and are overlain by subaerial cover loess-like formations. This section is proposed as a reference one for the Gelazian and Eopleistocene deposits of the extraglacial zone of the Pre-Yenisei Siberia.

RELIEF AND DEPOSITS OF THE LATE CENOZOIC PERIOD OF THE NORTHWESTERN PART OF THE CENTRAL YAKUT PLAIN AND ADJACENT TERRITORY OF THE EAST SIBERIAN PLATEAU (SHEET Q-51)

The so-called “watershed coarse gravels” of the Neogene were preserved within the development of heterochronous denudation peneplanation planes. Based on the comparison of paleontological data with the global eustatic Hague-Weil curve, a ladder of denudation levels is constructed. According to the latter, the age of alluvial are determined. Correlation of the deposits of erosion-accumulative terraces in the conditions of the Munsky neotectonic uplift with alluvium in the valley of the Lena is realised. For the latter, the Late Neo-Pleistocene-Holocene age is substantiated and separate geomorphological unit is proposed. The conclusion is made about the weak notion substantiation on the dammed origin of the Mavrinskaya Formation and its age range, the significant role of subaeral processes in its formation in the interval of the Samarovo-Muruktinskoye time is assumed.

ON THE STRATIGRAPHIC SIGNIFICANCE OF THE LOW TERRACES OF THE SUZUN STRATA OF THE UPPER OB RIVER REGION

Studies of the end of the 20th century showed that there are no sediments of the glacial-dammed lakesea, as well as sediments of periglacial alluvium in sections of low terraces of the Upper Ob River region, known as the Suzun Strata. The lower stage of terraces is composed of alluvial sediments, and the upper one is epresented by subaerial complex, which includes both deluvium and aeolian deposits. The height of areas varies significantly and is predetermined by thickness of the subaerial complex in each particular area. Сonsequently, the geomorphological principle does not work when differentiating the Suzun Strata into heterochronous geological bodies of accumulative terraces above the flood-plain.

PETROLEUM POTENTIAL QUANTITATIVE FORECAST OF DEEPLY-BURIED REGIONAL RESERVOIRS OF THE LOWER JURASSIC DEPOSITS WITHIN THE YENISEI-KHATANGA AND EASTERN GYDAN PETROLEUM REGIONS OF THE SIBERIAN SECTOR IN THE ARCTIC

The article presents the results of petroleum potential quantitative forecast of the Toarcian, Pliensbachian and Hettangian-Sinemurian regional reservoirs of Lower Jurassic deep-buried deposits within Yenisei-Khatanga and adjacent territories of the Gydan petroleum regions based on models of structure and reconstructed conditions of formation for each of the noted reservoirs and their components – permeable complexes and fluid seals, developed earlier by the authors of this article. Tectonic, lithological-facies and geochemical criteria for assessing the oil-and-gas bearing prospects of reservoirs are described. The methodology and the petroleum potential quantitative assessment results for regional reservoirs with attached maps of petroleum potential of each reservoir are considered. The structure of hydrocarbon resources (HC) is given: the distribution of initial total hydrocarbon resources by phase composition, regional reservoirs and oil and gas-bearing areas.

PROBLEMS OF THE QUATERNARY STRATIGRAPHY OF THE SIBERIAN REGION

This special issue of the journal is devoted to modern controversial subjects arising during the research of the Siberian Quaternary system. The initiative to discuss these problems and new factual material that requires rethinking outdated stratigraphic constructions belonged to the section of the Quaternary system of SIBRMSK and was supported by leading experts actively working in the region. It should be noted that this issue does not cover all the unresolved issues on the geology, stratigraphy and paleogeography of the Quaternary period of Siberia.