Vol 52 Iss. 2

All textbooks on the geology of mineral deposits provide only the geological and economic definition of a mineral deposit. This definition is usually formulated as follows: a mineral deposit is an area of the Earth's crust with a characteristic geological structure in which the mineral is concentrated in quantities sufficient for exploitation, and its quality meets the requirements of industry. This definition is correct, but it does not clearly reflect the economic side of the problem. The fact is that it is not always economically feasible to develop even such a deposit, in which the mineral is concentrated both in quantity and quality sufficient for exploitation. For example, chromite deposits in the Polar Urals are characterized by ores of high quality (magnoochromite metallurgical ores) and contain ore in quantities sufficient for exploitation. However, the development of these deposits is currently not economically feasible for the following main reasons: the nearest railroad station is 250 km away from the area of the deposits; carrying out a railroad or highway is associated with great difficulties due to swamps, sharply dissected relief and permafrost; there are no consumers of chromite ore in the Komi ASSR. Consequently, at present the chromite deposits of the Polar Urals cannot be considered industrial, although the ore here is of high quality and the quantity is sufficient for exploitation ...

Pegmatite fields confined to the zone of development of Hercynian granitoid intrusions on the eastern slope of the Urals have been studied, as is known, for a very long time. To a large extent, these pegmatites are among those natural objects on the example of which the classical theory of the genesis of pegmatite formations is built ...

As it is known, promising for crystal pegmatites are usually postorogenic, usually interformational, isometric in plan, shallowly eroded massifs of granites of essentially quartz-microcline composition with increased content of volatiles, formed in conditions of shallow depths. Our studies on more than thirty granitoid massifs allow us to refine some of these regional prospecting assumptions ...

The main task now facing quartz geologists is a thorough analysis of structural control The deposit, like most rock crystal deposits in adjacent areas, belongs to the northwestern strike-slip fault zone. The thickness of the zone reaches 500 m, its length - the first kilometers. The disturbance is characterized by lenticular-block structure, typical for similar formations in metamorphic rocks. The entire zone is composed of concordant lenses of quartz-mica schists and marbles of the Manya Formation (Pz, Cm) and lenses of Hercynian granodiorites ...

The ore field of the cobalt-copper deposit is confined to the zone of juxtaposition of large tectonic structures: the East-Tannuol anticlinorium and the West-Tannuol synclinorium. They intersect along the Ubsunur-Bayapkol deep fault, which can be traced from southwest to northeast for more than 100 km. The Ubsunur-Bayankol deep fault is adjoined to the east by the 80 km long-lived Ungesh fault zone. The intersection of these regional faults controls cobalt-nickel arsenide and cobalt-copper sulphoarsenide mineralization of the ore field under consideration ...

Apatite-nepheline bodies in the Khibiny are spatially confined to an arc-shaped intrusion of ijolite-urtite. They are gently inclined to the center of the massif and occur in its hanging flank at the contact with ricechorrites and medium-grained nepheline syenites. The shape of ore bodies is lenticular-platform, their thickness is from 10-30 to 100-150 m, and their dip to the center of the massif is 25-50°. The largest among them Kukisvumchorr-Yuksporr and Rasvumchorr ore bodies are located in the southwestern part of the arc-shaped band of ijolite-urtites and form the Southwestern ore field (S.M. Kirov, Yuksporr, Apatite Circus, Centralny mines). 15 km to the north of the ore field is the Kuelpor-Lavoyok deposit, 5 km to the east is the Koashva ...

The Vuoriyarvi massif belongs to the Paleozoic intrusive complex of ultrabasic alkaline rocks and carbonatites of the Kola Peninsula and Northern Karelia. Deposits and ore deposits of various ore and non-metallic minerals are confined to such massifs. Each type of minerals belongs to certain rocks composing a complex complex: ultrabasic rocks - titanium and phlogopite-vermiculite mineralization, carbonatites - rare elements. The issues of mineralogy, petrography and genesis of Vuorijärvi massif were paid much attention by many researchers. We have made an attempt on the basis of field studies to present the structure of the massif and the history of its formation ...

In the north-west of the RSFSR, the raw material base of the refractory industry is a group of refractory clay deposits in the Borovichi-Lubytinsky district of the Novgorod region. These deposits are exploited by the Borovichi Refractories Plant. In order to produce highly responsible fireclay refractories the plant needs dry, semi-dry and to a lesser extent plastic high refractory clays. Such clays are formed by large deposits at the deposits “Proletary”, “Bolshevik”, Ustye-Brynkino, im. Artema, etc. ...

There are many works devoted to the internal structure of pyrite, mainly related to the deposits. This article is devoted to the structure of pyrite, formed by metasomatic way in magnetite ores and skarns of Sarbaisky contact-metasomatic iron deposit. The internal structure of pyrite was studied by means of electrolytic etching using 10-20% NH40H solution as an electrolyte. The allotriomorphic and hypidiomorphic grain structure of aggregates and the shape of individual grains were revealed. Outside the ore deposit, the cube shape dominates, whereas the ores are most characterized by pentagondodecahedrons and octahedrons often in combination with the cube. Therefore, the shape of pentagonal and hexagonal, various trapezoids, less often squares, is quite characteristic for random slices of pyrite ...

In the domestic literature the classification of coal-bearing formations was discussed more than once and in different variants. In 1959 we published a new, more detailed, genetic classification of coal-bearing formations. Е. О. Pogrebitsky, critically estimating it, classifies coal-bearing formations differently ...

Exploration of deposits of asbestos is more and more often conducted by drilling works. Almost all known deposits of chrysotile-asbestos of the USSR are explored by wells of core drilling.As the long-term practice of exploration of these deposits shows, at sampling of a core of the wells drilled on asbestos-bearing rocks, the definition of the content of fiber in ores is somewhat distorted. It is connected with relatively big abrasion of rocks on separate intervals of a core, with grinding of asbestos fiber at drilling. The nature of the process of abrasion of cores from asbestos-bearing rocks and the degree of distortion of determination of asbestos content during core sampling have not been studied sufficiently ...

Geological and industrial classification of dolomite deposits, reflecting both the peculiarities of their geological structure and the peculiarities of their exploration and exploitation, plays an important role in the selection of the system of exploration and evaluation of deposits. However, the existing classifications of carbonate rock deposits do not fully solve these problems ...

Geological and industrial types of copper deposits are widely covered in the press, but usually consider only the most important geological factors that determine these types and very weakly (more often only indirectly) affecting the economic efficiency of copper deposits.As is known, as a basis for the classification of geological and industrial types of mineral deposits even geological factors different researchers take different ...

Conditions - a set of requirements set by the industry to the quality of mineral raw materials and mining and geological parameters of the deposit during delineation and calculation of reserves in the subsoil, compliance with which is achieved the correct division of reserves into balance and off-balance reserves. Under balance reserves according to the Classification are understood such reserves, the use of which is economically feasible, and under off-balance reserves - reserves, the use of which at present is not economically feasible, but which in the future may become the object of industrial development....

The conditions of prospecting and exploration of deposits, as rightly noted by V. I. Smirnov, are becoming more and more complicated every year, as most of the work is carried out in hard-to-reach areas and in an increasingly complex geological environment. In modern conditions, when the economic factor in the exploration of mineral deposits is given decisive importance, the problem of identifying such deposits and ore bodies, which contain the main industrial reserves of this type of mineral raw materials comes first...

Among the numerous problems arising for researchers of the geological structure of the southwestern Prionezhye region are questions about the presence and nature of tectonic disturbances in the field of development of the Iotian deposits of the Upper Proterozoic. The researcher's approach to the study of stratigraphy and tectonics of the Precambrian and prospects of mineral prospecting depends on the solution of these questions. If the presence of tectonic faults most researchers consider undoubted, there is no consensus on the nature of the faults ...

The most important fossils for the deposits of the Permian system are ammonoids and microfauna.The stratigraphy of the Permian deposits of the southern biogeographic areas (Tethys), which occupy a huge area on the globe, is developed mainly on the basis of microfauna. In the Urals, the longitudinal scale of the Permian sediments is based on the ammonoid fauna. Therefore, it is obvious that the Pamir area, where both divisions of the Permian system are fully represented by marine sediments containing a rich ammonoid fauna together with microfauna, is best suited for correlating the stratigraphic schemes of these areas ...

In the present article the results of granulometric analysis of gravel and pebble and conglomerate deposits developed in the territory of southwestern Kyzylkum and belonging to the Tashakyr and Sadyvar formations of Pliocene-Quaternary age are considered and compared ...

The exposition Magnetost in the Mining Museum is a part of the section Properties of Minerals of the General Mineralogy Department. In this section the concept of minerals is given, then the constitution of minerals is characterized, and then the properties of minerals as a function of their constitution are discussed. The task of the new exposition is to provide an extended volume of information about this property of minerals and its dependence on the peculiarities of mineral constitution. The exposition is realized according to the basic principle of a museum, which should be a stone book on mineralogy. It consists of mineral specimens and explanatory texts, diagrams and other exhibits, allowing to familiarize with the question completely in the museum ...