Suchergebnisse

The report presents the results of comprehensive studies of loess-like formations that are common within drainage basins of Ay and Yuruzan rivers (South Urals). Loess complexes associated with the third fluvial terrace. The lithological composition, structural and textural features indicate that the loess were formed like the part of alluvial fans, planned under the third fluvial terrace. The obtained palynological data indicate the formation of deposits in the Middle Pleistocene during the Odintsovo interglacial and Moscow glaciation.

Within the Western slope of the Southern Urals, there are plenty of basite dyke complexes of Riphean to Vendian among Precambrian terrigenous-carbonate formations. In metamorphic formations of the Taratash complex (Archean to Early Proterozoic, the northern closure of the Bashkirian meganticlinorium) there was observed the andesitic dyke with isotopic age of 71±1 Ma (U-Pb SHRIMP II on zircons) and near Bakal two bodies of gabbroids with zircons of similar ages were found. These are the first evidence of possible Mezozoic magmatism in this region.

The article presents the new data concerning the bounding zones of the Archean - Early Proterozoic Taratash block. It breaks the longitude structure of the Urals, squeezing all structural zones at a latitude of the town Miass. There were studied the meso- and microstructures of the boundary zones, anisotropy of magnetic susceptibility of faulted rocks and distribution of seismic waves velocities in to blastomylonites. We suggest that kinematic history of the Taratash block consists of two phases: 1) Middle Riphean exhumation of Taratash rocks in tension environ- ment; 2) Late Paleozoic formation of Indenter due regional shortening setting.

In this work we reported the structural features and mechanism of the formation of the Simskaya low of the Uralian foreland basin, besides the Karatau-Suleyman block as a whole. This block has the shape of a wedge, so with a general latitudinal compression, it experienced lateral extrusion to the north along the conjugated shear zones. This factor determined the local situation of meridional compression and latitudinal tension. In the central part of the block, the latitudinal stretching was compensated for by gradual deflection, which led to the formation of the Simskaya low.

In this work we reported the structural characteristics of the late Paleozoic flysch formation in the central part of the Uralian foreland basin. Three types of structural associations specific for thrust zones are established there. These include: 1) asymmetrical to recumbent west-vergent folds; 2) re-structured tectonic melange; 3) local thrusts, zone of schystosity, flat tectonic mirrors. Generally structural elements strike approximately parallel to the regional Karantrav thrust; orientation of striking ranges from the northwest to the northeast, accordingly to tectonic heterogeneity of the allochtone.

The paper presents the results of micropaleontological studies of a series of stones found during the study of the pier of the ancient Greek city of Phanagoria. The samples contain Upper Turonian–Coniacian, Campanian, and Maastrichtian foraminifers characteristic of the Central Tethys zones. This makes it possible to exclude the Crimea and the North Caucasus from the possible regions of origin of the samples. It has been established that Upper Cretaceous carbonate strata similar in genesis and chronology are located on the site of the southern coast of the Black Sea near the ancient cities of Heraclea and Sinop.

The structural features of the Katavsko-Yuryuzan faults zone are considered. According to the analysis of mesostructures, paleopole stresses, where horizontal northwest compression prevailed, were determined. Data on earthquakes, that occurred in September 2018 near the town of Katav-Ivanovsk, has been analyzed. Contradictions in determining the coordinates of epicenters and mechanisms of earthquakes foci calculated by different geological services were revealed. It is shown, that the situation of right-sided transpression, in which the structure of the northwestern part of the Bashkir meganticlinorium was formed, continues up to the present moment.

This article presents the results of studies of the material constitution and physical properties of rocks of foundation of the West Siberian Plate. It is shown that anthraxolite and kerite groups are present in bitumen rocks. We assume that the bitumens create a Late Paleozoic paleo-deposit, transformed under the conditions of apocatagenesis. Impregnation with highly transformed organic matter leads to a significant decrease in electrical resistivity to values of 1–30 Ohm metre, which must be taken into consideration when interpreting low-resistivity zones on log data.