Geology
A zonal ichthyofaunal stratigraphic scheme for different facies deposits from the Lower and Middle Triassic of European Russia is proposed for the first time. The scheme has been elaborated on ichthyofaunal complexes and groups with use of evolutionary trends among dipnoans, elasmobranchians and actinopterigians. Upper Permian zonal scheme on ichthyofauna is also clarified. Distribution of fishes in Triassic of Eastern-European platform is shown.
The joint Vendian-Riphean reservoir in the Yurubcheno-Tokhomskaya zone (YuTZ) of the Siberian Platform has resulted from hydrothermal activity. Prediction of the HC-prospective fields in the VendianRuphean deposits is based on revealing the zones of hydrothermal activity conductive to cavern and pore formation in the fractured carbonate series. Quartz-associated ankerites are indicator minerals for oil- and gas-saturated dolomites.
Manifestation of natural disasters during growth of cities in the Volga Region revealed amount of geoecological problems in the beginning of the 20th century. Increasing of these problems forced engineeringgeological research with elements of geoecological investigations in the Geological scientific Institute of Saratov University. This work provided a basis for geoecological, urboecological and agroecological research in the University.
This paper represents results of the complex research of the Senomanian deposits from right-bank of the Volga region. It is suggested to revise the stratigraphic position and the range of previously established Melovatka suite (1999) (Senomanian stage). It has been revealed that major part of the middle (silt-argillaceous packet) subsuite and the upper (sandy packet) sub-suite are missing from the stratotype section, but determined by the author within the Senomanian stage of the right-bank Volga region.
The paper represents an analysis of the vertical range of foraminifera in the Albian-Senomanian-Turonian interval from sections of rightbank of the Volga region (the south of the Penza, Saratov and the north of the Volgograd regions). It is suggested to establish two local biozones: Gavelenella cenomanica and Lingulogavelenella globosa within the Melovatkian suite (Senomanian stage).
The paper represents materials which evidently show small amplitude faults in the gravitational field, poorly seen in a wave field, and appearance of peak of instability among ∆g curves reflecting features of «thin structure» of the gravitational field which can be considered as objects potentially containing oil and gas. The purpose of this paper is an attraction of attention of users of subsoil resources on necessity to carry out precision gravimetric or even better to do gravimagnetic investigations along seismic profiles using combined scheme.
Based on geological survey data from previous years, it is safe to say that there is a possibility of oil and gas discovery in the Devonian terrigenous-carbonate deposits, similar to the findings in the regions known as the Ryazano-Saratovsky Basin and the Stepnovskaya Anticline, as well as its adjacent areas. Yet the geological structure and a potential for discovery of recoverable hydrocarbon deposits within the Svintsovskaya Depression are still unclear.
The Balantionella genus has been recognized by A. Schrammen (1902) from a single specimen and two skeleton fragments from a locality in the «quadrate» Cretaceous rocks in Germany. In the southeast of the Russian Plate, representatives of the genus have been determined within units from all the stages of the Upper Cretaceous. This has made it possible to provide characteristics and to trace the morphogenetic tendencies in the representatives of the group. Three subgenera and 12 species have been recognized.
The original method of correlative transformation of vibrograms, which takes into account the distortion of reference signals in environment with frequency-dependent attenuation on the energy of elastic vibrations. The experimental material shows that the proposed method of calculating correlograms allows to significantly improve the quality of vibroseis materials. The possibility of calculating the attenuation decrement, which carries a significant amount of additional information on the structure and properties of the geological section, is also discussed.
In this paper, we consider the technology of geological modeling of oil and gas reservoirs, based on the results of interpretation of the mud logging and well logging data. Informative geological and geophysical parameters for distinguishing marking horizons were determined. A technological scheme for opening productive reservoirs is proposed, based on the allocation of reference layers of different levels.
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