Геология

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.

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.

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.

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. Formation of the ?sponge?