Геология

To improve the efficiency of geophysical prospecting, the Department of Geophysics of the Faculty of Geology of Saratov State University develops original complexation technology allowing to evaluate the possibilities of identifying promising oil and gas areas by circular thermal-magnetic anomalies, limited to the gradient zones of areas of gravimagnetic complex parameter or geopotential fields anomalies itself. The article presents the experience of applying non-seismic elements of the complex of this technology.

The paper deals with regularities of postsedimentation changes in rocks at the halogenesis final stages within the Gremyachinskoye potassium salt field. Relation ship has been revealed among the postsedimentation processes, brine composition peculiarities, structure and regularities of terrigenous material inflow. Substanti al role of partial metasomatic replace mentofsalting-out halite in carnallite rocks is specified, as well as the role of diagenetic processes in halogen series, frequently accompanied with initial phases of plicative deformations.

The matrix method for solving the problem of Seismoelectrical effect of the second kind is suggested. The excitement of this effect in a horizontally-layered medium by a point source of mechanical vibrations is considered. An analytical solution of the problem of the second kind Seismoelectrical effect for a homogeneous space is obtained.

In article modern geothermal conditions of the main oil-and-gas complexes are analysed, temperature and deep borders of change of a phase condition of deposits of hydrocarbons are revealed, сonclusions are drawn on a possibility of the separate forecast of deposits of fluids, various on structure, in the considered territory.

The earliest assemblage of Cretaceous sponges has been found in the Cenomanian terrigenous rocks (the Melovatka suite) from the south of the Volga right bank region. A noticeable element of the assemblage is composed of small-sized Camerospongia, newly recognized in the region and peculiar for forming monotype colonies as well.

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.

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.

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.

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.

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