Геология

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 representatives ofthe genusEpicheloniceras Casey, 1954fromthe Middle Aptian of Mangyshlak, Western and Southern Turkmenistan are described.

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). 

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 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.

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.

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 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.

Within the skeletal structure of the medium- and the thick-walled Hexactinellids, the active filtration surface area was increased at expense of the elements of the irrigation system. The ostia and the transversal canal structures, the densities of their occurrences correlate with the values of the wall thickness, the skeleton habitus, the level of modular organization; they are in many ways determined by the parameters of the sponge habitats.

The character of kaolinite hydromicatization within the Donetsk Basin tonsteins in the course of metamorphism depends on the types of enclosing coals: either normal or salty ones. Alongside with terrigenous minerals within the coal-bearing masses and the fossil sea waters, indicator authigenous minerals from salty coals – halite and glauberite – should be specified as the sources of sodium and potassium for kaolinite hydromicatization.