Geology

Physical and geological model of the Shalkar earthquake focal zone

Authors: Ogadzhanov V. A.

The Shalkar earthquake focal zone is characterized by the strongest earthquakes of all that occurred in the southeast of the East – European Platform. A physical and geological model has been developed, on the basis of which the parameters of the Shalkar earthquake focal zone have been determined, which can be used to assess the intensity of shaking from possible earthquakes. The relationship between earthquakes in the southeast of the East European platform and deformations in the mantle is shown.

Oil as the result of lithogenesis complicated by intensification of tectonic-hydrothermal activity (on the example of Western Siberia)

Authors: Korobov A. D., Korobova L. A.

The paper is meant to prove that structural reconstruction of riftogenic basins is accompanied by the intensification of tectonichydrothermal activity. It controls the mobility of gaseous-liquid hydrocarbons during their primary and lateral migration in the process of deposit formation. The intensity index of tectonic-hydrothermal activation is equal to the ratio of maximum paleotemperatures of gaseous-liquid inclusions to the paleotemperatures calculated from vitrinite reflectance values.

Magnetostratigraphy of Turonian – Santonian strata on the Samara Right Bank

Authors: Gujikova A. A., Grishchenko V. A., Fomin V. A., Baraboshkin E. Y., Shelepov D. A.

The paper presents the results of petro- and paleomagnetic studies of two sections of Turonian – Santonian on the Samara Right Bank – near Novodevichye, Podval’e villages and detailed geological description of the Novodevichye section. The magnetostratigraphic subdivision and detailed correlation of the sections were carried out. Unknown unconformity in the Podval’e section was recognized.

Assessment of the facial affiliation of local oil and gas objects based on geophysical data

Authors: Golovin B. A., Golovin K. B., Kalinnikova M. V., Rudnev S. A.

In the established practice of geological exploration for oil and gas conclusions about the facies belonging of the rocks of oil and gas basins and individual exploration areas were made mainly on the basis of the study of core material. Recently for this purpose the results of seismic exploration and well logging have been used. Geophysical methods despite their obvious progress are indirect and intermittent core sampling and incomplete coring make facies analysis difficult.

Seismic gravimetric modeling in geological problems of Saratov region sections

Authors: Volkova E. N.

Geological and geophysical modeling is a modern and classic method of processing and interpretation, which is relevant in the segment of geological exploration of any geophysical method. The article presents the material of two-dimensional modeling based on the results of gravity and seismic exploration in the licensed areas of the Saratov region.

The investigation of the porosity scale effect and elastic anisotropy in Bashkirian limestones

Authors: Khassanov D. I., Andrushkevich O. Y., Lonshakov M. A.

The article presents the methodology of the representative elementary volume definition for 1 m long whole core segments. Scientific articles focused on factors controlling elastic properties are analysed. Terms of additivity and nonadditivity for physical properties of rocks are discussed. The algorithm of core sampling including drilling out of three perpendicular core samples for estimation of elastic anisotropy was used.

New data about Upper Jurassic formations of the Ulyanovsk-Saratov through and the northern part of the Peri-Сaspian Syneclise

Authors: Rogov M. A.

A detailed description of the Upper Jurassic formations of the south of the European part of Russia, mainly restricted by the Kimmeridgian and Volgian stages, is given. The characteristic of the reference section is provided for the Vechkusy Formation, and the neostratotype is proposed for the Novikovka Formation. The criteria for drawing the boundaries of local stratigraphic units (formations) and the features of strata distribution are considered in detail.

Some regularities of change in density in the lithosphere of Northern Eurasia

Authors: Ogadzhanov V. A.

A method is proposed for calculating the normal compaction curve of rocks for the deep parts of the lithosphere. It is based on the analysis of petrophysical characteristics and interpretation of gravitational anomalies. The main regularities of density changes in the lithosphere of Northern Eurasia are investigated.

Ichthyofauna of the border sediments of the Severodvinsky and Vyatsky stages in the Late Permian localities in the west of the Orenburg region (Samara river basin)

Authors: Minikh A. V., Yankevich D. I., Andrushkevich S. O., Andrushkevich O. Y.

A detailed study of the section of the severodvinsky and vyatsky stages of the Upper Permian with layer-by-layer sampling of ichthyofauna in the western part of the Orenburg region (basin of the lower reaches of the Samara River) was carried out. Based on the fish complexes, a paleontological justification of the stratigraphic boundary between the severodvinsky and vyatsky stages was obtained in the region for the first time.

The investigation of the scale effect on porosity in Bashkirian limestones

Authors: Khassanov D. I., Lonshakov M. A.

The article presents the methodology of the representative elementary volume definition for two 1 m long whole core segments. Scientific articles focused on practical methods of representative volume calculations using various physical parameter fluctuations have been studied. Porosity values of every whole core fragment evaluated in two ways using the 7.3 cm diameter core samples in the first approach and the 3 cm diameter core samples in the second one have been compared.

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