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


Геология

The Precaspian Depression Geothermal Conditions and Heat and Fluid Flows

The Precaspian depression subsoil geothermal mode characteristics result not only from presence of the huge evaporite formations and salt dome tectonics, but also from the depth structure of its no granite crust and underlying lithospheric mantle. The current heat flow is primarily of mantle origin and correlates with the HC, helium and other mobile components deep fluid flow.

Internal Salt Tectonics within the Halogenic Series in the Gremyachinskoye Potassium Salt Field

Explorations of 1979–1982 and 2006–2009 have made the field ready for industrial development and have revealed peculiar manifestations of internal salt tectonics within the subhorizontal halogenic bodies. The degree and the character of intrasalt tectonics are estimated according to boudinage, i. e. the response of the rigid dolomite- anhydrite interlayers within the salts to arising tectonic stresses. Upon folding, the interlayers are torn into separate fragments and stretched along the bedding.

Synsedimentation Hydrothermal Processes as Event Indicators for Interregional Correlations of Triassic Sequences

Event stratification of the sections constitutes an investigation trend aimed at detailed interregional correlation of sedimentary sequences. Based on extensive factual material, the authors have revealed the most significant changes in the Middle Triassic sedimentary and volcanogenic-sedimentary bodies. The entire Middle Triassic is peculiar for manifestations of hydrothermal-metasomatic processes within terrigenous, biogenic, volcanogenic bodies and bodies of mixed origins.

Ecological and Geochemical Research on Soil and Estimate of Dusting in the City of Volsk (the JSC ?Volskcement? Affection Zone)

Considered the results of ecological and geochemical soil sampling and made the estimate of dusting in the ?Volskcement? cement producing plant affection zone (the city of Volsk, Saratov region), which is the city-forming company and also the main source of environmental impact

Earth’s Response to Orbital Excitation and Hierarchy of Climatic Events and Rock Cyclites Over the Recent Time

Analysis of the published material has made it possible to show the cyclic variations of the earth’s response to be practically coincident with the orbit parameter fluctuations, when the time lag of 5–6 thousand years is considered. In the earth’s response, however, periodicity changes are more complicated due to resonance phenomena and to numerous feedbacks in the system responsible for additional period occurrences.

Main Features of the Permian Halogenesis Hydrochemistry in the Caspian Region

In 1960–1980, the Elton and the Gremyachka deposits of potassium salts were discovered within the Permian halogen sequences in the Lower Volga Region, bischofite presence was recorded in the Privolzhskaya monocline, the conditions of halogen-bed formation were defined as those peculiar for typical evaporites. But in 1980-2010, halogenesis hypotheses emerged that denied the principal importance of climatic factor and the dominant role of oceanic waters in the brine composition of the salt-generating basin.

Magnetic Structures as Indicators Some Features of Formations of Tithonian-Berriasian Rocks in the Mountain Crimea

Anisotropy of magnetic susceptibility was measured in ~ 1,300 samples from 10 sections of the Tithonian-berriasian of the Central and Eastern Crimea. In consequence of the analysis of magnetic structures were found different degrees of tectonic deformation of rocks and corrected geological structure of explored area

Terrigenous-mineralogic Characteristics of the Bobrikovskian Horizon from the Saratov Trans-Volga Region: Paleogeographical Aspects

Terrigenous-mineralogic characteristics of the Bobrikovskian horizon within the Saratov Trans-Volga Region is provided in terms of the Berezovskaya group of rises. The quantitative and the qualitative composition changes of the heavy fraction minerals within the section have been determined. The lack of abrupt, intermittent changes of any material composition characteristics testifies to the section relative continuity.

The Use of Microbial Indicators in Environmental Soil Monitoring of the City Mednogorsk

A microbiological indication of anthropogenic disturbed soils from the city Mednogorsk was carried out based on the evaluation of the number of heterotrophic, iron- and manganese-oxidizing bacteria. This study states a relationship between high levels of magnetism in these soil samples and high content of iron-oxidizing bacteria, indicating the possible use of this group of microorganism for monitoring heavy metal contaminated soils.

Colonial Level of Modular Organization in the Late Cretaceous Hexactinellids (Porifera). Genuine Colonies

Tendencies of morphogenesis in the Late Cretaceous modular forms contributed to formations of complexly structured secondary (genuine) colonies. Skeletons of genuine colonial sponges differ not just in numerous and diversely arranged equivalent oscula-carrying modules, but in the presence of the module connecting elements – junctions, as well. Characteristic elements of genuine colony skeletons – ostia – have been recognized between the modules and the junctions.

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