Geology

Auutygenic Dolomite High-сarbon Radials Bajenovskaya Switches – Indicator of the Regime Active Singenic Naptidogenesis

The article is devoted to the role of algal material of the Bazhenov suite in the the formation of authigenic dolomite. Authigenic dolomite could form in the environment of convergence of two processes: hydrothermal («wedging out» in the rear zones) and catagenetic (background) generated by conductive heat transfer. The development of the algal dolomite in situ shows that the source rocks experienced the stage of intensive (final) hydrocarbons generation.

First Magnetostratigraphic Data on the Maastrihtian of Mountain Crimea (Bakhchysarai Region)

The representative data about magnetic susceptibility, its anisotropy before and after heating up to 500°C and other petromagnetic characteristics were received on two sections of carbonate sediments of Maastrihtian – Chahmahly and Takma, located in Bakhchysarai region of the Republic of Crimea. In the studied sections there were established the magnetozones of normal and anomalous polarity, the comparison of determined zones with Geomagnetic Polarity Time Scale was conducted.

On the Stratigraphic Significance of Elasmobranchs (Chondrichtyes, Elasmobranchii)) in the Cenomanian of the Volga River Basin (Right Bank)

The paper analyzes the stratigraphic distribution of elasmobranchs in the deposits of the Melovatka Formation (Cenomanian) from the right bank of the Volga (part of the Penza, Saratov and Volgograd regions).

Secondary Terrigenous Screens of the Tyumen Switch – Reliable Factor of Preservation of Productivity Bazheno-аbalak Complex

Reliable isolation of the Bazhenov-Abalak complex of the Krasnoleninskoye field, ensuring its productivity, was provided by the appearance of secondary (hydrothermal) screens in underlying rocks of the Tyumen Suite. This was reflected in the sealing of the intergranular space of sandstones, silty sandstones and other rocks of the Tyumen suite with regenerative quartz, minerals of silica, and rarely sulphates and carbonates.

The Anomalous Lithosphere and the Oil and Gas Potential of the Precaspian Depression

The lithosphere of the Precaspian depression is characterized by abnormal ratios of the super-thick sedimentary cover and the thinlayered suboceanic crust, as well as anomalous structure of the decompacted upper mantle. The classic models of isostatic equilibrium for the Precaspian depression are insufficient and applicable only to a first approximation.

New Data on Magnetic Properties of Upper Paleozoic Deposits in the South of Precaspian Depression

The magnetic properties of igneous and sedimentary rocks of Lower Carboniferous and Upper Permian, were studied in the core samples from the boreholes, situated in the south of Precaspian depression. The volcanic rocks of Lower Carboniferous are characterized by low (first decades 10-5 SI units), and Upper Permian – by high (hundreds and first thousands 10-5 SI units) values of volume magnetic susceptibility.

The Petrophysical Survey of Radioactive Logging for Interpritation (in South-West Part of Pribortovaya Zone Prikaspiy)

In this article was studied clayiness of key bed of Aleksinskie depositsof Severo-Limanskaya region. It was executed 14 analyses of big collection of mineral aggregateusing X-ray analysis. It was received quantity relations clayiness and silty parts in key clayiness beds. It was calculated qualified significances of hydrogen index for examined key bed, using known valuesof hydrogen content of basic clayiness minerals.

What is the «Anthropocene»?

The unofficial term ≪Anthropocene≫ is used actively to refer of the era of the global role of mankind in changing of the environment. Its beginning was announced at the International Geological Congress in 2016. Earlier geologists abstained from this discussion, and representatives of other Earth and Life sciences prevailed among supporters of anthropocene’s idea. In the near future, the introduction of the anthropocene in the geochronological scale will be of current interest.

Integrated Bio and Magnetostratigraphic Study of the ≪Ozerki≫ Sections (Upper Cretaceous, Right Bank of the Volga in the Saratov Region). Paper 2. Oryctocoenosis Characteristics and Biostratigraphy

In the ≪Ozerki≫ sections, in the terrigenous and carbonate rocks, a faunal complex has been determined – unusually diversified and relatively abundant for the right-bank part of the Saratov Region. Examination of the specified groups of fossil invertebrates has allowed to propose variants for biostratigraphic division and correlation of the sections under consideration. The carbonate rocks are supposed to belong to the Turonian-Coniacian and the underlying terrigenouscarbonate rocks are regarded as the Lower Turonian ones.

Module Organization in the Late Cretaceous Hexactinellids (Hexactinellida, Porifera)

Knowledge on the regularities of vegetative propagation and comprehension of the osculum (oscula) and subosculum structural-functional positions and interrelations in the skeleton structure have made it possible to specify the organization levels in the Late Cretaceous hexactinellids: the unitary (solitary, perifrontal and autonomous forms), transitory (solitary, autonomous and colonial forms) and colonial (primary and true colonies) ones.

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