Геология

In the right-bank part of the Saratov Region, a section of terrigenous and carbonate rocks has been determined to underlie the ?sponge? horizon conventionally dated back to the Santonian. The maximum thickness of the marls, constituting a substantial portion of the section, occurs in the western part of the region.

On the base of spectral Fourier analysis of magnetic susceptibility time series of nearly 10 000 measurements of rock samples in the turonian-maastrihtian sediments, exposed near Nizhnyaya Bannovka village (Volga River Right Bank, Southern Saratov Region) there were detected long and short eccentricity cycles. Petromagnetic variations, correlated with different variants of eustatic curves detected the presence of well known sequences.

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. Formation of the ?sponge?

This article is about geochemical characteristics of oil shales in the Volzhkaia oil shale formation. Tendency of changing of TOC, REE and biophile elements has been examined laterally and vertically based upon cross cuttings of Perelubskoe and Kotsebinskoe developments. Possible interrelation between concentration of molybdenum and rhenium in the Volzhskii basin has been discovered. Intervals of ash material and their potential genesis have been closely considered.

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.

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.

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.

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 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.

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.