Geology

Hydrothermal Processes in Basement Rocks of the West Siberian Oil and Gas Province

Using Palyanovskoye oil field of Krasnoleninsk arch we demonstrated that local cataclasis and pneumatolytic-hydrothermal metasomatism manifestations are widespread in the Paleozoic basement rocks. For the first time the earliest indications of deep fluid activity were detected – at the stage of granite deep fluid saturation and primary diffuse leaching of feldspars. During transition to the infiltration process, they comprise jet-stream fibroblast structures formed due to biotite and plagioclase resorption by amphibole and scapolite association.

Morphogeneses of the Late Cretaceous Guettardiscyphia (Porifera, Hexactinellida)

Guettardiscyphia skeletons are peculiar for thin walls and highly dense apo- and prosopores. Wall mobility was conductive to formation of conical lobate skeletons of various, occasionally geometrically regular outlines. Substantial number of fossil samples from variously composed rocks from all the Upper Cretaceous intervals has made it possible to trace skeleton transformations in sponge ontogenesis and depending on their environmental conditions.

Environmental Management – Combining Agricultural Technology and Geology

Most of the Volga phosphate deposits are categorized as hard to recover, therefore traditional mining can result in environmental problems. An experimental rig model was manufactured for the shaftless mineral production from the thin productive layers. The projected productive capacity of a single production unit is 20,000 tons per year.

Typomorphism of Clastogene Quartz from the «Melovatka-5» and «Melovatka-6» Sections (the Cenomanian from the Southeast of the Russian Plate)

The paper deals withthe methods forstudying typomorphic featuresof clastogene quartz grains from the Melovatka suite terrigenou srocks within the stratotype and parastratotype sections. Calculated and observable typomorphic features of quartz grains have been examined; statistic analyses of their sphericity and isometricity parameter values have been made. Criteria for determining petrogenic or lithogenic nature of clastogene quartz have been specified.

Peculiarities of Formation of Anthropogenic Hydrochemical Anomalies in Groundwater within the Oil and Gas Fields

During long-term operation of oil and gas fields in the groundwater on their territory are formed hydrogeochemical anomalies expressed primarily chlorellaman type chemical composition, typical of the zone of active water exchange. The formation of the chemical composition of groundwater is influenced by many factors, both natural and manmade.

Regenerative Capabilities in the Late Cretaceous Hexactinellids (Porifera, Hexactinellida)

Partial and complete regeneration phenomena, cases of skeleton habitus restoration have been recorded in representatives of the Late Cretaceous hexactinnelids. Regeneration incidences are in many ways associated with the ability of silicon-producing cells responsible for constructing skeleton-generating elements, spicules, to transform, to rearrange their functions in response to the changes of the organism position on the substrate surface and/or upon the changes of the aquatic environment parameters.

Permian and Triassic Fish Holotypes Kept in the Earth Sciences Museum at the Saratov State University. Article 1. Dipnoian and Elasmobranchian Fishes

The paper presents the first review of the Permian and Triassic fish holotypes belonging to two classes (Sarcopterygii and Chondrich Chondrichthyes), recognized by the authors upon collecting and examining ichthyofauna bone remains from the sections within the East European Platform and the adjacent regions. Starting from the 1960-ties, 3 genera and 26 species of those fishes have been defined and used alongside with actinopterygian fishes to compile stratigraphic charts of the Permian and Triassic from European Russia and to make paleogeographic reconstructions.

Petromagnetic Indicators of Layers with High Concentration of Cosmogenic Substance in Maastrichtian of Volga Region and Cis-Caspian Region

The level with anomalous high values of natural remanent magnetization and Koenigsberger ratios was identify in the Upper Maastrichtian of Vol’sk depression (Saratov Volga Region). The microprobe studies of samples from this layer registered elevated concentrations of microparticles of iron, nickel, intermetallics and magnetite spherules of cosmic genesis. Similar petromagnetic anomaly was detect in the uppermost of Maastrichtian in the South Cis-Caspian (Aktolagay Plateau, Kazakhstan).

Geochemical Conditions of the Development of Modern and Buried Soils of the Middle Volga Region

The article presents datas on the gross chemical composition of buried soils of Subatantic and Subboreal periods, that’s located on geosystems floodplain of the Middle Volga. Based on the evaluation of geochemical factors justified bioclimatic conditions of their development, as well as the peculiarities of the process of soil formation. The comparative geochemical characteristics of buried soils with their zonal analogues (leached chernozem).

The Early Carboniferous Volcanism in the Southeastern Precaspian Depression

The problem of Paleozoic volcanism in the southeastern Precaspian depression remains unsolved despite its relevance. Obtained by the authors results can be most adequately explained from the plate tectonics standpoint as the evidence of subduction and subsequent collision that created the Precaspian Basin southeastern framing.

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