Geology

Conditions for the formation of deposits in the upper part of the Berriasian section near v. Alekseevka, Belogorsk region, Republic of Crimea

The results of the paleoecological analysis on ostracods of the upper part of Sultanovskaya Formation (Boissieri zone) in the section near v. Alekseevka are presented. Five ostracod assemblages reflecting changing conditions in the paleobasin are defined. It was established that the sedimentation in the Late Berriasian time occurred under conditions of a warm normally salty with a calm hydrodynamic regime of the basin, mainly in oxygen waters.

Pseudoderivations of Paracraticularia cylindrica (Michelin, 1840) (Porifera, Hexactinellida)

The morphological diversity of diosculumic sponges, known as Paracraticularia cylindrical, results from the fact that many fossils assigned to this species prove to be fragments of the apical segments of internodes (branches) from major colonies that are rarely encountered as totally preserved fossils. The structures of the branch apical segments and the oscula outlines reflect various manifestations of hexactinellida synchronous division conductive to morphological diversity of the descendants, the succeeding complicatedly structured colonial sponges.

Lithological and petrophysical characteristics of the deposits of the Vogulkinskaya strata within the maly Teterevsky shaft (Shaimsky oil and gas region)

Study results of the material composition and conditions of forming P Vogulkinskaya strata of the Tolumskoye field are presented. It is established that the formation of sediments occurred in coastal-marine conditions, in the transgressive stage of the sedimentation basin development. According to the composition of the allotigenic part, the studied sandstones and siltstones correspond to the quartz, grauwack and arkose groups.

Cygnus from the late pleistocene of Bingadi asphalt deposits of Azerbaijan

Two species of Cygnus from the Late Pleistocene deposits of Binagadi asphalt lake are described in this paper, which have not been previously known from this locality. Cygnus cygnus is represented by the left distal fragment of the radius; the right fragment of the proximal humerus and ulna belongs to Cygnus olor. Morphological analysis with recent and fossil species of the genus Cygnus makes it possible to establish taxonomic differences between species, based on certain diagnostic features that can serve as criteria for identifying species.

Current problems in the North Caspian depression geology and oil and gas prospects

The deep structure and formation of the North Caspian (Precaspian) depression have not been fully understood due to the scarcity of depth studies at 18–22 km. The existing concepts and hypotheses are clearly insufficient to interpret the unexplained facts. New approaches and research efforts are necessary to solve the old problems. The current state of the depression deep structure problems is reviewed, and the existing explanation flaws are demonstrated. The depression consolidated crust has oceanic and riftogenic origin as it has been suggested by the author before.

Physical and geological model of the Shalkar earthquake focal zone

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)

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

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

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

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.

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