Geology

New data on the Late Permian actinopterygian fish Toyemia Minich, a zonal genus of the Permian biostratigraphic scheme based on ichthyofauna from the Eastern Europe

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

The structure of the actinopterygian fish genus and speciesToyemia tverdochlebovi Minich has been completed for the first time using a previously unknown complete skeleton and skeletal fragments from Late Permian localities of Eastern Europe. The structure of a head which so far remained unknown in the genus is described. The dorsal fin location far from the head near the caudal region was confirmed as expressed earlier by the taxon’s author.

A new locality of chondrichthyan fishes from the Upper Paleocene on the right bank of the Don river (Volgograd region)

Authors: Lopyrev V. A., Popov E. V.

An assemblage of chondrichthyans is described from the new locality near Serafimovich town (the western part of Volgograd region). More than 2500 fossils were collected from the basal gravel-pebble bed and phosphorite-bearing layer from the lower part of the Buzinovka formation (upper Paleocene). There are reworked Cretaceous and Paleocene chondrichthyans (6 species) and synchronous 21 species of sharks and 2 species of chimaeroids.

Nannopterygius finds in the West Kazakhstan region of the Republic of Kazakhstan

Authors: Yakupova J. B., Akhmedenov K. M.

This article describes the skeletal fragments of new species of ichthyosaurus Nannopterygius mikhailovi sp. nov. and Nannopterygius yakimenkae sp. nov. from the Upper Volga sublayer of the Upper Jurassic of the West Kazakhstan region of the Republic of Kazakhstan (Shchuchkino section). The species are assigned to the genus Nannopterygius.

Results of the reconnaissance magnetostratigraphic studies of Paleocene in the southern part of the Saratov right bank

Authors: Shelepov D. A., Guzhikov A. Y.

The results of rock-magnetic and paleomagnetic studies of two sections of the Lower Syzran subformation (Paleocene) of the Saratov Right Bank – the Syrt Mountain (Nizhnyaya Bannovka village) and Lysaya Gora (Saratov city) are presented. For the first time the possibility of obtaining paleomagnetic data on the Paleocene of the Volga region and their use for magnetostratigraphic purposes despite the partial remagnetization of rocks has been established.

Natural conditions of the Popigai diamond deposit (North-West Yakutia)

Authors: Zheleznyak M. N., Shatz M. M., Misaylov I. E.

The article highlights the features of the diamond mining industry in Yakutia. The history of the discovery and study of impact diamonds Popigai deposit formed as a result of the penetration of the eponumous huge meteorite into the rock mass are traced. Some features of Popigai crystals and the prospects of their use in various sectors of the national economy of the country are characterized.

Conditions for the formation of deposits in the upper part of the Berriasian section near v. Alekseevka, Belogorsk region, Republic of Crimea

Authors: Savelieva Y. N.

The results of the paleoecological analysis on ostracods of the upper part of Sultanovskaya Formation (Boissieri zone) in the section near v. Alekseevka are presented. Five ostracod assemblages reflecting changing conditions in the paleobasin are defined. It was established that the sedimentation in the Late Berriasian time occurred under conditions of a warm normally salty with a calm hydrodynamic regime of the basin, mainly in oxygen waters.

Pseudoderivations of Paracraticularia cylindrica (Michelin, 1840) (Porifera, Hexactinellida)

Authors: Pervushov E. M.

The morphological diversity of diosculumic sponges, known as Paracraticularia cylindrical, results from the fact that many fossils assigned to this species prove to be fragments of the apical segments of internodes (branches) from major colonies that are rarely encountered as totally preserved fossils. The structures of the branch apical segments and the oscula outlines reflect various manifestations of hexactinellida synchronous division conductive to morphological diversity of the descendants, the succeeding complicatedly structured colonial sponges.

Lithological and petrophysical characteristics of the deposits of the Vogulkinskaya strata within the maly Teterevsky shaft (Shaimsky oil and gas region)

Authors: Pavlenko K. V., Titov Y. V., Galimova G. M., Kuklin E. A.

Study results of the material composition and conditions of forming P Vogulkinskaya strata of the Tolumskoye field are presented. It is established that the formation of sediments occurred in coastal-marine conditions, in the transgressive stage of the sedimentation basin development. According to the composition of the allotigenic part, the studied sandstones and siltstones correspond to the quartz, grauwack and arkose groups.

Cygnus from the late pleistocene of Bingadi asphalt deposits of Azerbaijan

Authors: Mustafayev I. M.

Two species of Cygnus from the Late Pleistocene deposits of Binagadi asphalt lake are described in this paper, which have not been previously known from this locality. Cygnus cygnus is represented by the left distal fragment of the radius; the right fragment of the proximal humerus and ulna belongs to Cygnus olor. Morphological analysis with recent and fossil species of the genus Cygnus makes it possible to establish taxonomic differences between species, based on certain diagnostic features that can serve as criteria for identifying species.

Current problems in the North Caspian depression geology and oil and gas prospects

Authors: Richter Y. A.

The deep structure and formation of the North Caspian (Precaspian) depression have not been fully understood due to the scarcity of depth studies at 18–22 km. The existing concepts and hypotheses are clearly insufficient to interpret the unexplained facts. New approaches and research efforts are necessary to solve the old problems. The current state of the depression deep structure problems is reviewed, and the existing explanation flaws are demonstrated. The depression consolidated crust has oceanic and riftogenic origin as it has been suggested by the author before.

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