Izvestiya of Saratov University.
ISSN 1819-7663 (Print)
ISSN 2542-1921 (Online)


Геология

Earth’s Magnetic Field Evolution During Last 24 mln Years

The history of Earth’s magnetic field during the last 24mln years is considered in terms of our regional magnetostratigraphic Neogene scheme of the southern European Russia and Transcaucasian region. The scheme results from the author’s paleomagnetic studies of base sections in the Caucasian region and bore holes in the northern Cis-Caspian and Lower Volga regions. The revealed inversions of the geomagnetic field are referenced to the stratigraphic scale of the Eastern Para-Tethys. Peculiarities of the magnetic polarity changes in Neogene are analyzed.

Paleogeographic and Tectonic Environment in the Lower Permian Halogen Formation from the Southeastern Margin of the Russian Plate

The Lower Permian halogen formation within the southeastern margin of the Russian Plate is to be considered a large one in terms of its spatial extent, thickness and completeness of halogen sedimentation development. Examination of the halogen formation has made it possible to construct lithology-facies maps of individual salt-accumulation stages and to determine the spatial migration of the salt-generating basin in time.

Biogenic Migration of Cd, Pb, Ni, and As in the «Soil– Plant» System and Change in Soil Biological Activity

The role of agricultural plants in the migration of Cd, Pb, Ni, and As in the soil-plant system and their contribution to decreasing soil metal toxicosis were studied. The influence of heavy metals and arsenic on the enzyme activity of southern chernozem and the restoration of soil biological activity during the elimination of these elements from planted soil were investigated. 

Geological-Tectonic Interpretation of Gravity-Magnetic Information in Development of Regional Geophysical Profiles (for Example: the Profile «Uvarovo-Svobodniy»)

The article deals with the results of geological interpretation of geophysical data received during traversing («Uvarovo-Svobodny» line, the length is 376 km). Integrated gravitomagnetic installations alongside were applied during the process of interpretation. The new tectonic elements were found, and previously found tectonic elements were confirmed. More accurate information about location of the border separating the mentioned tectonic elements was obtained. 

A New Approach to the Derivation of Eikonal for Inhomogeneous Anisotropic Elastic Media

The proposed new approach to seismic radiation, is based on fixing the amplitude of the displacement vector, reduce them to a system of implicit functions. This allows you to find the functional dependence between the time of arrival of the waves and spatial coordinates. The system of vector equations. The eigenvalues of the matrix in the system are the equations of eikonal. It is shown that for arbitrarily anisotropic and heterogeneous elastic medium, the maximum number of equations eikonal equal to three.

Ichthyofauna from the Key Sections of the Middle and Upper Permian of Eastern Europe: Complexes and Zonal Scale. Paper 1: Basin of the Severnaya Dvina River

The paper presents new material on ichthyofauna from the key section of the Middle and Upper Permian of the Severnaya Dvina River. Stratigraphic distributions of fish taxa are traced back and significant changes to the fish complexes are proposed. A modified paleoichthyological zonal scheme of the region is proposed as a result.

Noble, Scattered and Colored Metals in the Combustible Schists of the Volzhsky Shale Basin

The Volga shale basin is located in the southeastern part of the East European Platform within the Volga-Urals anteclise and the instrumental zone of the Caspian depression. The sediments of the Volga tier of the Upper Jurassic are sedimentary in the basin. The geological reserves of the Volga shale basin are more than 40 billion tons. Investigations of oil shale revealed the presence in it of significant contents of dispersed and noble metals, rhenium and platinum group metals: palladium, rhodium, iridium, ruthenium.

Upper Cretaceous Deposits and Biostratigraphy of the «Novospasskoe» Section (South-West of the Ulyanovsk Region)

The section of campanian deposits of the south-west of the Ulyanovsk region characterized by a strata of “knotty” chalk is described. It was found relatively numerous faunal complex presented mostly by belemnites, bivalves and echinoids. The diversity of epibiontic organisms is described. The study of fauna has helped clarify stratigraphic position of the section within the scope of valid regional scheme.

Sanitary Condition of the Gully System and the Problem of the Organization of Runoff from the City Territory of Saratov in the Late XIX Century

At the end of the 19th century the urban sanitary commission was created for the solution of problems of improvement in the territory of Saratov. In 1890 this commission made the inspection of Glebuchev ravine as zones of sanitary and ecological trouble. By results of researches health officers prepared the analysis of a condition of the territory and the recommendation on the improvement of Saratov. The expressed opinions differed significantly, and reflected the different views on the mechanism of improvement of the sanitary and hygienic situation.

The Research Results of the Physical Properties of Soil in the Village Piterka and Their Ecological Importance

The results of the study of soil in the village Piterka Saratov region. It analyzed the particle size distribution and magnetic susceptibility of soils. The results of particle size analysis can form an idea of the sorption properties of soil, and the results of measurement of the magnetic susceptibility – the transformation of the soil and brings man-made magnetic material.

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