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.
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.
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.
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.
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.
The article highlights the features of the diamond mining industry in Yakutia. The history of the discovery and study of impact diamonds Popigai deposit formed as a result of the penetration of the eponumous huge meteorite into the rock mass are traced. Some features of Popigai crystals and the prospects of their use in various sectors of the national economy of the country are characterized.
The results of rock-magnetic and paleomagnetic studies of two sections of the Lower Syzran subformation (Paleocene) of the Saratov Right Bank – the Syrt Mountain (Nizhnyaya Bannovka village) and Lysaya Gora (Saratov city) are presented. For the first time the possibility of obtaining paleomagnetic data on the Paleocene of the Volga region and their use for magnetostratigraphic purposes despite the partial remagnetization of rocks has been established.
This article describes the skeletal fragments of new species of ichthyosaurus Nannopterygius mikhailovi sp. nov. and Nannopterygius yakimenkae sp. nov. from the Upper Volga sublayer of the Upper Jurassic of the West Kazakhstan region of the Republic of Kazakhstan (Shchuchkino section). The species are assigned to the genus Nannopterygius.
An assemblage of chondrichthyans is described from the new locality near Serafimovich town (the western part of Volgograd region). More than 2500 fossils were collected from the basal gravel-pebble bed and phosphorite-bearing layer from the lower part of the Buzinovka formation (upper Paleocene). There are reworked Cretaceous and Paleocene chondrichthyans (6 species) and synchronous 21 species of sharks and 2 species of chimaeroids.
The structure of the actinopterygian fish genus and speciesToyemia tverdochlebovi Minich has been completed for the first time using a previously unknown complete skeleton and skeletal fragments from Late Permian localities of Eastern Europe. The structure of a head which so far remained unknown in the genus is described. The dorsal fin location far from the head near the caudal region was confirmed as expressed earlier by the taxon’s author.
Using a complex of remote and surface geophysical methods in the eastern part of the East European Platform, regional meridional heterogeneities were revealed; it is shown that these heterogeneities can be caused by low-density and magnetically active rocks in the crystalline crust and mantle. The totality of geological and geophysical data indicates the relationship of meridional heterogeneities with transcontinental deep faults.
The article presents the study results of the ammonite subfamily Cheloniceratinae Spath, 1923 representatives (genera Cheloniceras Hyatt, 1900 and Epicheloniceras Casey, 1954) fromthe Lower and Middle Aptian of Mangyshlak, Western and Southern Turkmenistan. The diversity and stratigraphic distribution of species is assessed, intraspecific variability is identified and typified. Representatives of the genus Cheloniceras are described.
The work is carried out approbation of the algorithm for the complex interpretation of geophysical data using data classification algorithm. Distributions by class are obtained and compared with petrophysical materials from published sources. This data is compared and geological composition of the studied area is obtained. The applicability of this approach for the integrated interpretation of geophysical data is shown, including low-level studied areas with a complex geological structure.
Based on the analysis of gravitational and magnetic anomalies of the eastern part of the East European Platform, it is concluded that inhomogeneities caused by serpentinization processes are present in the Earth’s crust. This conclusion is confirmed by conducting geological and geophysical studies on reference objects with serpentinite outcrops.
The paper analyzes the taxonomic composition and the habitat of the representatives of the Middle – Late Cenomanian and the Middle Turonian marine biota. The examined fossils have been isolated from the bulk sample obtained from the phosphorite horizon lying in the bottom of the Middle Turonian carbonate rocks in the Senomanskaya Stenka section (Volgograd Region, Zhirnovsk district).
The Paleogene quartz sandstones of the Sosnovka formation are widely occurred in the Uljanovsk-Syzran Volga region and are used as valuable building materials. The article comprises an improvement for the continental origin of the Sosnovka sandstones based on the results of a comprehensive study of the features of the mineral composition and microstructure of quartz sandstones of the Sosnovka formation obtained by using petrographic, XRD and electron-microscopic analyses.
The paper presents biostratinomical characteristics of the Cenomanian and the Turonian fossil complexes found in the Middle Turonian phosphorite horizon from the Senomanskaya Stenka section (Volgograd region, Zhirnovsk district) constituting the basis of the benthic colonies and nekton communities. Probable interpretations for the settings contributory to generation of the phosphorite inclusion clusters are provided.
Study of the skeletal morphology of a new representative of the Leptophragmidae family, with no suboscula in its structure, provides support for the earlier specified regularities in generation of Hexactinellida modular forms. Good preservation state of a major colony has made it possible to specify the aspects of paleoecology and taphonomy in the later representatives of the Middle Coniacian – Early Santonian succession of siliceous sponges.
The article considers method application results of correlation analysis of gravitational and magnetic field data, heat flux values, data of decoding satellite images measured in the regions of the Pre-Caspian and Scythian large concentric morphological structures of the central type. As a result, using the correlation method, a complex of various geophysical fields in these regions was analyzed. Local concentric morphological structures with high values of the gravitational field and heat flow promising for the search of new oil and gas fields were identified.