Geology

Cribricyaths of the Lower Cambrian Oldynda Suite (Western Transbaikalia)

A large number of cribricyaths previously considered as archaeocyathan larvae was found in the carbonate deposits of Oldynda suite. Described by A. G. Vologdin in 1932 cribricyaths are characteristic of the lower Cambrian deposits of Ural-Mongolian belt and are rarely found outside of it. They are known from the Tommotian of Altai-Sayan folded area and their further development took place on the periphery of the Siberian platform.

The Reversal Polarity Zone in Turonian-Coniacian of the Northern End of DonoMedvediza Dislocations

The Gubkino Horizon (Turonian-Coniacian) in the Bolshoy Kamenny ovrag section (Zhirnovsk town, Volgograd Region) has not been purposefully studied so far. As a result of biostratigraphic and magnetostratigraphic researches the carbonate rocks of the Gubkino Horizon were first divided into zones based on benthic foraminifera complexes and characterized by geomagnetic polarity and rock-magnetism data. The most part of the Bolshoy Kamenny ovrag section is covered by the reverse polarity zone.

The Santonian Stage in Volsk-Khvalynsk Structural Zone. Paper 2. Biostratigraphy and the Modern Structural Position

The fossil assemblage taxonomical composition analysis of upper Coniacianlower Santonian, upper Santonian and lower Campanian deposits is demonstrated. The upper Coniacian and lower Santonian deposits planoconformity has been recorded, the thin upper Santonian deposits presence has been proved and the lower Campanian subface position has been defined. Fractional biostratigraphy subdivision of the Coniacian – lower Campanian interval was carried out. The distinguished strata were traced within Volsk-Khvalynsky district.

The Santonian Stage in Volsk-Khvalynsk Structural Zone. Paper 1. The Research History and the Composition of Sections

The horizon enriched in glauconite and phosphorite was revealed at the carbonatic outcrops near Volsk in the Coniacian and Campanian stage deposits. The short descriptions of studying sections are presented. The spread of synchronous deposits within Khvalynsky district was traced. The Lower and Upper Santonian and the Campanian age deposits are proved by the presence of the inoceramids, belemnites and echinoides. Its vertical distribution was traced.

Upper Cretaceous Calcareous Sponges of the Southeast of East European Platform

The features of areal distribution and stratigraphic confinement of calcareous spicular sponge forms in the southeast of East European Platform are considered. The skeletons of calcareous sponges essentially representatives of the genus Porosphaera are found in the carbonates of Turonian, Coniacian, Campanian and Maastrichtian, as well as at the base of siliceous formations of the Paleocene. The Maastrichtian calcareous sponges are characterized by the highest species diversity and a wide lateral extension.

Bio-, Magneto and Cyclostratigraphy of Upper Berriasian near V. Alexeevka (Belogorskiy Region, Republic of Crimea). Article 2. Foraminifers, Ostracods, Сalpionellids, Organic-Walled Dinoflagellate Cysts

The paper presents the results of the micropaleontological study of the upper part of Sultanovka formation and Zelenogorsk formation (Berriasian) near Alekseevka village (Belogorsk area, Central Crimea). The representative assemblages of foraminifers and ostracods, as well as calpionellids and palynomorphs, are found in the Sultanovka formation.

Equivalent Geoelectric Sections in the Transient Electromagnetic Method

A criterion for the equivalence of geoelectric sections in the transient electromagnetic method is formulated. It is shown that the equivalence of geoelectric sections is closely related to the simplification of multilayer conductive geoelectric media by replacing them with a small number of macroanisotropic conductive layers. An algorithm for constructing equivalent sections is proposed. Various examples of equivalent sections for various models of multilayer horizontally layered conducting media are given.

The Relation between the Stages of Organic Matter Transformation in Coals and Mineral Components of Inter-Coalarkosesandstones (an the Example of Lena and Irkutsk Basins)

The research has first revealed the direct relation between the secondary changes in the coalinclosing rocks and the metamorphosis degrees of the coals themselves. Geochemical balance has been proved to develop within the “coal organic matter – sandstone mineral matter” system in tectonic environments providing combination of low-temperature propylitization in arkose sandstones and caustobiolith coalification ranks of G and F.

Reliability Increase in Oil and Gas Perspective Objects Forecast on the Basis of Polarizing Filtration

This article focuses on the problem of improving seismic data reliability of seismic data during oil and gas exploration. As one of the most effective ways to solve this problem, the authors consider the application of polarization filtering. For its practical implementation it is offered to use new adaptive technology. It is characterized by high technological effectiveness, advanced capabilities to allow peculiarities of reflectors polarization and interference waves in specific seismogeological conditions.

Ichthyofauna from the Key Sections of the Middle and Upper Permian of Eastern Europe. Complexes and Zonal Scale. Paper 2: Basin of the Volga and the Ural Rivers

Material on ichthyofauna from the Middle and Upper Permian of Eastern Europe was revised. New fish taxa from the Permian key sections of the basin of the Volga and the Ural Rivers significantly expanded composition of the complexes. the stratigraphic and geographical distribution of fish has been traced. A more precise zonal scale of the Middle and Upper Permian of the Eastern Europe based on ichthyofauna has been proposed. 

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