Lithotectonic regularities in distribution of Cenomanian phosphorites in the Dnieper-Donets Depression

Peculiarities in the distribution of nodular phosphorites in two largest phosphorite-bearing deposits (Polpino and Shchigry) of the Voronezh anteclise are considered. Section structure, phosphorites occurrence mode, conditions and succession of authigenic mineral formation in Cenomanian sands are analyzed. Various phosphate phyto-and zoomorphs are described.The second part of the paper is dedicated to lithotectonic regularities in the distribution of Cenomanian nodular phosphorite deposits. History of the origination and development of the science of structural-facies analysis is considered. Close relations of local tectonic structures with the distribution of coal, oil, salt, and other mineral resources are demonstrated. The distribution of nodular phosphorite deposits in the Dnieper-Donets Depression depends on local synsedimentary uplifts of two types.     

Influence of a change in the underlying surface roughness on the formation of a pattern from radioactive contamination

The influence of a change in the surface roughness z₀ on the air flow speed over this surface is considered. It is shown that a twofold change in the parameter (from 0.01 to 0.02) results in a disturbed speed of the air flow, which attenuates both with height and distance. The maximal disturbance can amount to 30% at a height of 5 m, it is already 3–5% at a height of 40 m, and it totally disappears at a height of 100 m. In the horizontal, the disturbance can spread for 1.5–2 km. The estimates of radioactive contamination of the underlying surface, under conditions of a nuclear power enterprise accident, demonstrated that the disturbance can lead to no less than a twofold error of the area of radioactive contamination.     

Sedimentary basins: Regularities in their formation and classification principles. Communication 2. Sedimentary rock basins

The article is dedicated to sedimentary rock basins. It is postulated that sedimentary rock basins represent an element of the Earth’s sedimentary shell characterized by the general thermobaric regime, type of fluidodynamics, and combination of epigenetic mineral resources. Fluidodynamic regimes of three types are recognized in the upper part of the crust: infiltration, elision, and exfiltration. The dominant type of fluidodynamics is reflected in the most widespread mineralogical-geochemical zonality and association of epigenetic mineral deposits. These properties allow us to define the infiltration and elision types of rock basin in the sedimentary shell. The structural features of different-type rock basins are characterized with the emphasis on their relations with geotectonics.     

Evolution of lithology at the Geological Institute,Russian Academy of Sciences

Based on the comparison of early and late works by academician N.M. Strakhov, typification of lithogenesis, which covers the entire recent sedimentation on continents and in the oceanic segment of the Earth, is proposed. It is shown that early stages of sedimentogenesis play a decisive role in the formation of the facies-formation structure of the lithosphere. Attempts to oppose exogenic factor with endogenic one in the formation of sedimentary rocks are criticized.     

Phase differentiation of matter in the sedimentary process

The paper is dedicated to the problem of material differentiation in the sedimentation zone, in mud sediments at the diagenesis stage, and at deep levels of the sedimentary cover during catagenesis. The role of academician N.M. Strakhov in substantiating the recent concept of phase differentiation and its significance for understanding ore genesis is emphasized.     

Elision systems of the Dnieper-Donets aulacogen: Communication 1. Geological structure of the aulacogen and catagenetic processes in the Ciscaucasus and greater Donbas

The geological structure of the Dnieper-Donets aulacogen is characterized. It includes two elision systems, which are compared with the previously investigated system of the Ciscaucasus region (hereafter, Ciscaucasia). Particular attention is paid to the elision system of the Donets basin, development of which is related to the accumulation of peat and the coalification of Carbonaceous sequences. It is emphasized that this process should be considered an important geological factor responsible for folding.     

Geochemical problems of the behavior of phosphorus: A basis for the biogenic hypothesis of phosphorite formation

The most important problems of the phosphorite formation are considered. It is shown that phosphorus is a typical biogenic component, which is concentrated in the course of biogenic sulfate reduction at the mud stage of transformation of rocks highly enriched in organic matter due to acidification of solutions, while precipitation is stimulated by alkalinization of the interstitial and rock solutions by carbonates. The role of terrestrial source in the formation of phosphorite deposits is emphasized.