Vol 58 Iss. 2

On August 9, 1968, the Leningrad Mining Institute suffered a heavy loss: Vitaly I. Bodylevsky, Professor of the Department of Historical Geology, passed away. Vitaly Ivanovich gave fifty years of his life to the Mining Institute and during these long years trained and educated many hundreds of geologists, became a leading specialist in the field of paleontology and stratigraphy of the Mesozoic, a scientist of world renown.

The question of the Precambrian, its scope, the history of the development of the Earth's crust in Precambrian time and the similarities and differences between it and later geologic epochs is currently being extensively discussed.

The long domination in Soviet geotectonics of ideas about the sharp predominance of vertical movements over horizontal movements in the Earth's crust led to the fact that the doctrine of strike‑slip faults was almost not developed for many years. Strike‑slip faults have completely ceased to be identified in geological mapping, and geologists began increasingly to substitute the wide range of disjunctive dislocations in regional geological literature with the rather impersonal term fault...

According to the latest ideas, the Dnieper-Donets Depression is a transverse aulacogen that arose in the late stages of the Russian Platform development in the Middle Devonian, when not only the platform basement but also a significant part of the platform cover had already been formed...

Alkaline-ultrabasic magmatic manifestations in the north of Middle Siberia are known in the northern marginal part of the Siberian Platform and in the south of the Taimyr folded region. These manifestations of magmatism, confined to two different geostructural zones, are separated by the Yenisei-Khatanga trough. Alkaline-ultrabasic magmatism developed in parallel with trap magmatism during the formation of the Upper Paleozoic-Mesozoic structural stage.

The Tannuol intrusion, one of the largest Lower Paleozoic granitoid intrusions of Tuva, which has a very complex petrographic composition and multiphase character of formation, was long considered as a plate-shaped body confined to the boundary of two lithologically and structurally different Cambrian and Ordovician formations, or as a folded flat-shaped body with steeply dipping wings in some folds. Structural and microstructural analysis of this intrusion has forced a reconsideration of the above notions.

Widespread in the Dzungarian Alatau Hercynian granitoid intrusions are divided by many geologists into two complexes: the Central Dzungarian and the younger Lepsin, to which different metallogenic potential is attributed. However, the attribution of specific massifs to one or another complex in many cases causes discussion and remains unresolved due to the lack of clear age boundaries for most of the large massifs, ambiguity of determinations of absolute age and diversity of material composition...

In recent years, on the southern slopes of the Dzungarian Alatau , peculiar vein alkaline-basaltoid rocks have been discovered and studied, which in terms of the totality of geological and petrographic-mineralogical features correspond to camptonites. A characteristic feature of these rocks is the abundance of various clastic inclusions, mostly of deep origin. The study of these inclusions is of undoubted interest in connection with the problem of the genesis of lamprophyres and the structure of deep horizons of the Earth's crust and upper mantle.

The Daldyno‑Alakitsky area is located in the basin of the upper reaches of the Markha and Alakita rivers, in the northeastern marginal part of the Tunguska syneclise. Certain issues of the geological structure of the area have been considered in a number of works. The authors of these works make contradictory conclusions about the distribution patterns of kimberlite bodies and the time of formation of fold and fault structures due to different opinions about the nature of the relationship between kimberlites and traps, the conditions and sequence of their manifestation...

Within the Mamsko‑Chuyskaya pegmatite province , bodies of giganto‑migmatites are widely distributed, characterized by an exceptional variety of forms and complexity of internal structure.

The geological literature has long known examples of localization of dike complex rocks or hydrothermal veins in cracks of shear‑type discontinuities. Characteristically, all the examples of fracture formation associated with horizontal flexures described in the geologic literature necessarily reflect the conditions that arise during the development of large‑scale strike‑slip faults.

The position of the peninsula at the junction of the Mesozoic and Alpine folding zones and the presence of a rigid massif in the northwest caused a sharp difference in the geologic structure of its northwestern, central, and southeastern parts.

In recent years, an independent complex of dikes of diorite porphyrites, granite porphyries and granosyenite porphyries of Cretaceous age, confined to the zone of intense Mesozoic activation of the Precambrian platform, has been identified in the central part of the Stanovoy folded area. The dikes were described by E. P. Gurova and E. P. Gurov, who, unfortunately, did not take into account the works of the FESU, described in this article.

The deposit is located 300 m south of the operating Sarbaiskoye deposit on the western wing of the Sokolovsko Sarbaisky anticline in the sequence of sedimentary volcanogenic Paleozoic rocks overlain by young (Cr₁–Q) loose sediments 80 120 m thick. …

The reconstruction of the history of sedimentation processes is invariably based on the analysis of the composition, structure and relationships of rocks composing geological sections. For such an analysis, a convenient and currently accepted form of depiction is the construction of geological sections to the scale of bed thickness.

Conversion of geological sections from the thickness scale to the time scale opens up the possibility of applying harmonic analysis to reveal periods of the still large cyclicity of sedimentation processes. At the same time, such an analysis of geological sections is impossible without representing them in the form of periodic curves, i.e. without their formalization.

Most researchers of the Khabarovsk Krai are of the opinion that the structural forms of the basement of the Northern Sikhote Alin and the Lower Priamurye were formed on the site of the Sikhote Alin geosyncline. The folded structures recorded in the modern erosional cross section in the basins of the Urmi, Burey, the upper reaches of the Amgun, Nimelen and in the more northern areas of the South Western Priokhotye belong to the so called Mongolian Okhotsk geosyncline or geosynclinal system...

In the search for oil and gas deposits, the study of tectonic discontinuities in the rock continuity of sedimentary cover and the basement rocks is of great importance. The application of various methods of morphostructural and morphometric analysis in closed areas speeds up and reduces the cost of prospecting, as well as significantly improves the quality of geological exploration.