Vol 31

Even a cursory review of the geological map of the Crystal Belt of the Subpolar Urals leads to the conclusion that numerous deposits of piezo-optical quartz are localized in the metamorphic strata of the Proterozoic and Lower Silurian, and in the northeast are quite clearly delineated by outcrops of the third formation. It should be noted that the lower formation is composed predominantly of mica schists, the middle - of quartzites, and the upper - of limestones. Consequently, the partitioning of the metamorphic strata of the Subpolar Urals characterizes not only the relative age of the formations, but also the peculiarities of the chemical composition of the rocks. Therefore, within the crustal band stratigraphic search features are inseparably connected with lithologic ones. In addition, the dependence of the mineral composition of crystal nests on the chemistry of the host rocks is quite definitely outlined even on a regional scale: essentially quartz rocks - Proterozoic shales and quartzites of the Lower Silurian are saturated with nests with quartz crystals, while limestones of the Upper Formation do not contain crystal vaults.

Until recent years, the general geologic structure of the Arctic remained obscure because its entire central part is occupied by the waters of the polar seas, making the relationships of the structures of the surrounding continents appear quite uncertain. During a number of years (1945-1952) the author, on behalf of the Arctic Institute of GUSMP, conducted thematic work to decipher the geological structure of the Central Arctic. To solve this problem, a summary of new materials on the structures of the northern part of the surrounding continents and islands, as well as interpretation of geophysical and bathymetric data on the central part of the Arctic (gravimetry, magnetometry, seismometry) was performed. As a result of the review of the actual material on the geological structure of the coasts and islands of the Polar Basin, it is possible to outline the location of the geological structures of the Arctic, as well as to assume their continuation to the north. At the same time, new geophysical data are an important addition to the geological data, which makes it possible to trace the continuation of the main structures in the areas enclosed by the waters of the Polar Basin. Geophysical data are the basis for solving structural questions for three areas: 1) north of Spitsbergen and Severnaya Zemlya; 2) north of the Novosibirsk Islands and 3) on the meridian of Wrangel Island, at 77° N.

In 1947 in Central Dagestan in the base of the limestone strata of the Lower Cretaceous, in the vicinity of the village of. Zuri-Makhi (according to the map Puri-Makhi) of Sergokala district, the author of this article discovered a celestine deposit. Due to the end of the field season it was impossible to trace the distribution of celestine-bearing strata in other points of the southwestern wing of the Mugrinsky anticline. This opportunity presented itself in 1949, when it was possible to visit a number of points and get acquainted with the section of the limestone sequence of the southwestern wing of the Mugrinskaya anticline in the vicinity of the village of Khantskarki-Makhi. Khantskarki-Makhi, located to the west of the village of Nizhnie Mulebki. Nizhniye Mulebki. The study of the area of Mugrinskaya anticline allowed to find out that the celestine-bearing strata has a significant distribution over the area and is of interest as an object for staging prospecting and exploration works.

A set of magmatic formations associated with the Upper Paleozoic-Lower Mesozoic magmatic cycle, similar in geologic position, as well as in mineralogical and chemical composition, researchers refer to the Siberian Trappe Formation. This formation includes intrusive and effusive rocks of basic composition, pyroclastic formations of tuffogenic strata of the Angarsk series (Tunguska Formation), which were formed due to products of early phases of volcanic activity. These rocks within the northern and central parts of the Siberian Platform occupy a vast territory. For example, tuffogenic deposits of the late Paleozoic and early Mesozoic, as well as lava covers overlying them, are located in the basins of the Nizhnaya and Podkamennaya Tungusok, Kureika, Khatanga, upper and middle reaches of the Kotuy, Kheta and upper Olenek rivers. The area occupied by them is at least 700,000 km². At present, magmatic formations of this territory attract great attention of researchers in connection with the development of such important issues as stratigraphy and tectonics of volcanogenic formations and processes of volcanism. The study of these issues will help to reveal the industrial prospects of this vast territory.

The present article is devoted to the development of issues related to the search for sulfide ore bodies missed and lost by mine workings in copper mines of the Urals by means of electrical exploration methods. In it the technique of searching for sulfide ore bodies from mine workings by a complex of electrical prospecting methods (shadow and method of measuring the natural electric field) is given and the possibility of using them in the presence of interfering influence of underground mine power generation is shown. The prospecting works confirmed the success of the proposed method, good performance of the used equipment, accuracy and completeness of interpretation of the shadow method materials. In addition, the present work considers the possibility of application of DC methods for the purposes of prospecting and exploration of ore bodies from mine workings.

In the present work, on the basis of physiographic, permafrost conditions and geological and structural features, for the first time in the literature, a brief description of the hydrogeology of one of the areas of the southern part of the Yakut artesian basin - the vicinity of the town of Olekminsk - is given. The work utilizes materials of the thematic party of the All-Russian Geological Institute - YaSU, which was headed by the author in 1951 -1953, and some literature data on the geology and hydrogeology of the Olekminsky district of the YASSR. The area considered in this paper, occupying a small area of the left bank of the Lena River in the vicinity of Olekminsk, is located in the southern part of the Yakut artesian basin, discovered in 1939-1940 by a team of hydrogeologists and permafrost scientists (Prof. N. I. Tolstikhin, M. I. Sumgin, Associate Professor V. M. Maksimov, Prof. V. M. Maksimov, Prof. N. I. Tolstikhin, M. I. Sumgin, and Prof. V. M. Maksimov). V. M. Maksimov, Ph.D. in Geology and Mineral Sciences A. M. Efimov, P. I. Melnikov, and Ing. V. A. Obruchev. The town of Olekminsk is a district and cultural center. It is connected with other settlements of Yakutia by dirt roads, water and air routes. The Lena River serves as the main waterway for transportation of goods and passengers from Olekminsk downstream and upstream of the river. This old waterway continues well beyond the boundaries of the study area, linking Olekminsk with Yakutsk and the village of Ust-Kut, from which it passes. Ust-Kut, from which runs a highway and railroad to the village of Zayarsk (on the Angara), linking the area with the Siberian railroad.

In 1951 -1952 we studied hydrogeological conditions of Bayangolskoye coal deposit in south-western Transbaikalia in order to estimate expected groundwater inflows into mine workings. The materials of these studies are the basis of this article. Hydrogeological conditions of Bayangolskoye coal deposit area are characterized by a great variety of ground waters, complexity of conditions of their formation and interrelation, and at the same time they are rather typical for the whole south-western Transbaikalia. Bayangolskoe coal deposit is located in the basin of the Dzhida River in the Zakamensky District of the Buryat-Mongol ASSR (Fig. 1), in the southern piedmont part of the Khamar-Daban Range, on the watershed of the Myla-Burun-Mylykhey Rivers (right slope of the Bayangol Pad). The Khamar-Daban Range is one of the branches of the Eastern Sayan and represents the watershed between the systems of the Dzhida and Irkut rivers.

Among the developed coal deposits of the USSR, the Suchan deposit is one of the most complicated by geological features and mining and operational factors. It is characterized by the following main features. The deposit is strongly dislocated. Pliquefactive and disjunctive tectonics is sharply expressed. Coal seams (as horizons) are pronounced but variable in thickness and quality. The coal-bearing strata along the weakening planes are cut by eruptive rocks with manifestations of contact metamorphism. Due to the fact that anticlinal parts of the folds are denuded to a large extent, the developed coal seams are contained in synclinal parts of the folds. It is of undoubted interest to find out from the exploitation data the distribution of displacements and the forms in which they appear in these conditions.

Many works have been devoted to the geology of the Crimean Peninsula and the eruptive rocks developed here, most of which are based on personal observations of researchers. However, in a number of these works and in subsequent summaries of the Crimea to date, sometimes repeated incorrect conclusions of some researchers. Incorrect conclusions can be found both in specialized literature and in various reference books and guides for tourists and excursionists. Misconceptions include, in particular, the question of the formation of the chaos of Alupka Park, which is the subject of this article. In the light of these perceptions, the chaos is explained as the result of a grandiose collapse of eruptive rocks, moved a considerable distance down the slope from the place of its original occurrence.

Yakutsk artesian basin is one of the largest basins in the USSR in terms of area and thickness of sedimentary strata, different in composition, age and origin. The area of the basin is more than one million square kilometers. The thickness of sedimentary deposits is measured in kilometers. In terms of area, this basin exceeds the Dnieper-Donets, Moscow, Verkhnelensk, Kansk, Irkutsk, Khatanga, Nizhnezeisky artesian basins and the largest basin in Western Europe - the Paris basin. Thus, the Yakutsk artesian basin occupies a central position among the following hydrogeological areas of the USSR: the Khatanga basin in the north, the Tunguska basin and the Anabar hydrogeological massif in the west, the Verkhnelensk basin and the Aldan hydrogeological massif in the south, and the Verkhoyansk hydrogeological folded area in the east.

Hydrogeological observations of groundwater regime are of great importance in the development of fields located in complex hydrogeological conditions. Numerous examples from the practice of development of waterlogged fields show that the cause of groundwater breakthroughs in mine workings is often an insufficient study of hydrogeological conditions of the field and lack of control over the regime of groundwater. Groundwater breakthroughs often delay mining operations for a long time, and their elimination is associated with large expenditures of material and technical resources. But with well-organized hydrogeological observations of the regime of these waters and their correct interpretation usually manages to prevent the occurrence of breakthroughs, and if they occurred, to outline the fastest and most effective ways of their elimination. At the same time, it is essential to identify the source of the breakthrough, which, of course, facilitates the fight against groundwater.

The first works on hydrometallurgy of molybdenum were started by the Leningrad Mining Institute in 1932 and were carried out on poor raw materials of the Takhtarvumchorr deposit, extremely far from the usual conditions. During the next two years the results of these works were discussed and approved at the broad meetings held by Academician A.E. Fersman in Kirovsk and Leningrad, but they were used in practice later, in connection with the problem of extraction of molybdenum contained in the Balkhash copper ores. In October 1941, a shop was put into operation at the Balkhash plant for processing of substandard molybdenum products using a method developed at the Leningrad Mining Institute.