Geology

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

Authors: Pervushov E. M., Seltzer V. B., Kalyakin E. A., Fomin V. A., Ryabov I. P., Ilinskiy E. I., Gujikova A. A., Biryukov A. В., Surinskiy A. M.

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)

Authors: Pervushov E. M.

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.

Geochemical Characteristics of Oil Shales in the Volzhskii Basin and Productive Forecast of Rhenium Commercial Concentrations

Authors: Ilyasov V. S., Staroverov V. N., Vorobieva E. V., Reshetnikov M. V.

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.

Experience of Cyclostratigraphic Analysis of Petromagnetic Data on the Turonian–Maastrihtian Section «Nizhnyaya Bannovka» (Volga River Right Bank, Southern Saratov Region)

Authors: Surinskiy A. M., Guzhikov A. Y.

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. The study includes the calculations of sedimentation rates, localization of sedimentation breaks and estimation of their duration.

Integrated bio and Magnetostratigraphic Study of the ≪Ozerki Sections≫ (Upper Cretaceous, Right Bank of the Volga in the Saratov Region). Paper 1. Section Characteristics, Results of Petromagnetic and Magnetic-mineralogical Examinations

Authors: Pervushov E. M., Seltzer V. B., Kalyakin E. A., Fomin V. A., Ryabov I. P., Ilinskiy E. I., Gujikova A. A., Biryukov A. В., Surinskiy A. M.

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. Field description is presented alongside with the correlation scheme of the recognized stratified intervals in the three joined Ozerki objects and the results of petromagnetic and magnetic-mineralogical examinations in the carbonate rock interval.

A New Species Actinopterygian from the Upper Permian of Moscow Syneclise

Authors: Minikh A. V., Andrushkevich S. O.

A new species actinopterygian fish Isadia opokiensis sp. nov. (Eurynotoidiidae, Eurynotoidiformes) of the Late Permian from Moscow syneclise are described.

Rhenium in the Volzhsky Stage Deposits of the Volga Shale Basin Central Part

Authors: Samoilov A. G., Zozyrev N. Y., Engalychev S. Y., Shelepov D. A., Ilyasov V. N.

Multibillion oil shale resources within the Volga shale basin central part (Privolzhsky Federal District: Samara, Saratov, Ulyanovsk, and Orenburg regions) are low-quality sulfurous mineral raw materials. The commercial rhenium content in oil shale was found in the randomly selected samples from the Kashpirsky, Orlovsky, Perelyubsky, and Kotsebinsky fields. Rhenium concentration varies from 0.013 to 0.22 g/t with the ore marginal commercial concentration (as a concomitant component) of 0.05 g/t.

Localization of the Anomalies of Geopotential Fields on the Basis of the Frequency and Correlation of Change

Authors: Ryskin M. I.

The considered methods of separation of gravity and magnetic anomalies in order to distinguish the local search objects. Shows the examples of practical application of these techniques.

Morphotypes of the Late Cretaceous Hexactinellids (Porifera, Hexactinellida)

Authors: Pervushov E. M.

Basic structure types have been specified in hexacinellids with soldered spicule lattice. The fossils of those occur as skeletal forms. Certain tendencies in Lychniscosa and Hexactinosa morphogenesis were identified as conductive to shaping the spectrum of skeleton archetypes. The increase of sponge morphological diversity was in many ways predetermined by thickness reduction of the skeleton-forming walls, associated with reduction of the irrigation system elements. That has brought about forms of complicated tubular labyrinth habits.

Features of Mineral Composition North Shchigry and Rogowski Diorite-granodiorite Arays of Kursk Block (Central Russia)

Authors: Kushcheva N. S.

North Shchigry and Rogowski diorite-granodiorite arrays are intrusive shtok bodies. As part of the intrusions of rocks studied potassium feldspar, plagioclase, hornblende magnesia, phlogopite, muscovite, quartz, and epidote.

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