Vol 30 Iss. 2

The magmatic origin of the solutions from which the crystal-bearing quartz veins of the studied region were formed is recognized by most researchers. Of all the questions related to the genesis of crystal-bearing quartz veins, the main and decisive one is the question of the source of the substance and especially the source of silica in the hydrothermal solutions from which these deposits were formed. But it is precisely on this issue that there are the greatest and most fundamental disagreements between researchers of rock crystal deposits not only in the studied region, but throughout the world. Some researchers consider the magmatic chamber to be the main source of the substance in hydrothermal solutions, while others believe the host rocks. Since this dispute is based mainly on hypothetical reasoning rather than direct observations and data, this issue remains controversial to this day. Moreover, the dispute between researchers of rock crystal deposits has taken on such a long-lasting nature, apparently also because none of the researchers has attempted to approach the solution of this problem, dividing it into two components: the source of silica in quartz veins and the source of the substance, including silica in crystal nests. In this regard, the convincing arguments of the supporters of one theory were shattered by the no less convincing arguments of the supporters of opposing views. The correct solution to the question of the source of silica, and all other components of crystal-bearing quartz veins, is not a purely academic dispute, but undoubtedly has great practical significance.

The Taurida Formation of Crimea is a unique sandy shale formation dating back to the Upper Triassic - Lower Jurassic. It is usually called the "shale formation" or "Taurida shales", sometimes its flysch nature is mentioned, and a very complex folded structure is noted, but these features do not provide a sufficiently complete description. In 1937-1940, and then in 1946-1951, we studied the Taurida Formation in all the main areas of its distribution - on the northern slopes of the Crimean Mountains, to the southeast of the Simferopol-Bakhchisarai line (the environs of Simferopol and the upper reaches of the Alma, Bodrak, Kacha and Belbek rivers), and on the southern slopes of the Crimean Mountains, along the Black Sea coast - from Simeiz to Alushta and east of the latter. Everywhere, the Taurida Formation has a number of similar features in its material composition, alternation of rock varieties (rhythmicity) and the nature of the folded structure. All these features indicate that the Taurida strata are typical flysch strata. It should be emphasized that the layers of the Taurida strata are often inverted bedding. Therefore, it is necessary to be able to easily establish the true bedding of the layers in each outcrop based on their macroscopic features. The identification of such features of the Taurida strata is the main objective of this article.

In the row all the geological sciences, the science of prospecting and exploration of mineral deposits is one of the youngest. It is advisable to formulate the definition of the subject and method of science as follows: prospecting and exploration is the science of the methods of discovery, qualitative and quantitative characteristics and assessment of mineral deposits for the purpose of their industrial use. The method of this science consists in studying the dependence of the methods of discovery and establishment of the qualitative and quantitative characteristics of deposits on the geological patterns that determine the formation and all the features of mineral deposits. The main tasks facing the science of prospecting and exploration are as follows: on the basis of the analysis and generalization of the vast factual material and experience of prospecting and exploration accumulated to date, to develop new and improve the applied systems of geological exploration. In this case, special attention should be paid to the development of issues of rational spatial placement of workings and other observation points, as well as the development of prospecting and exploration techniques.

When developing coal deposits, seams and associated mine workings are depicted on plans and sections. A seam plan and a vertical cross-section across the strike of rocks through the opening workings are mandatory components of a set of basic mine surveying plans for any conditions of coal seam occurrence. In conditions of steep seam dip, in addition to the above, a vertical projection of the seam onto a vertical plane passing through a line parallel to the dominant strike of the seam is also necessarily drawn up. When developing a group of inclined and steeply dipping seams, a horizontal section ("horizon" plan) is also drawn up with an image of the seams, capital and main development workings on it. On the listed mine surveying plans and sections - the main technical documents of the mine - the conditions of seam occurrence, and consequently, fault dislocations (displacements) must be properly reflected. A number of mandatory requirements are imposed on the specified documentation, contained in the current instructions and symbols.

For specialists in coal geology, foredeeps acquired special interest after the connection of these structures with coal content became indisputable. Establishing this connection was complicated by the fact that some authors classified foredeeps as platforms, others as geosynclines, and finally, others, not without some justification, classified them in a new, special (third) category, equivalent to a geosyncline and a platform, calling it a transitional region. It was necessary to clarify this complex, purely tectonic issue, which contains a number of contradictions and misunderstandings caused in part by the inaccuracy of definitions and distinctions between various concepts. This article does not pretend to introduce any new tectonic concepts or provisions. It aims to analyze existing ideas about foredeeps from historical, geological and logical positions. In an effort to understand the issue of the position and development of foredeeps, the author tries not to lose sight of the verification abstract reasoning with a connection to coal-bearing capacity and practice. The article poses a number of elementary questions to tectonists in the hope that they will express their final point of view and bring to completion those thoughts that were expressed only preliminary.

Such minerals as muscovite, feldspars, ores of a number of valuable metals - lithium, beryllium, partly niobium, tantalum, elements of the rare earth group, etc., are mostly extracted from pegmatite deposits. The industrial significance of pegmatite bodies is constantly increasing. Pegmatites, in addition, are often receptacles of many rare minerals, and in some cases serve as natural museums of beautiful crystals, which attracts the special attention of mineralogists. The peculiarity of the genesis of pegmatites has long been of interest to petrologists and geochemists. In the phenomena of pegmatite formation, researchers encounter perhaps the most complex process of mineral formation, with which one can perhaps compare only the process of skarn formation. When studying pegmatites, the interests of petrologists and mineralogists are closely intertwined. In pegmatites, phenomena that indicate the general features of various processes of mineral formation and transformation the rocks that make up the veins are manifested with such exceptional clarity and on such, often, enormous scales that in other types of deposits they are generally unknown or are discovered in a much less clear form.

Study of the structure of the ore field of the Bazhenov asbestos region shows that when determining the possible location of "blind" deposits, one should primarily proceed from the tectonic elements of the structure. Lithological factors only narrow the area of ​​chrysotile asbestos deposit searches, limiting it to the peridotite part of the ultrabasic rock massif. The connection of asbestos formation with weakly mineralized hydrothermal solutions leads to the exclusion from the search area of ​​areas with intensive development of quartz-carbonate, talc-carbonate and talc rocks that arose under the influence of high-temperature, highly mineralized solutions of granite intrusion. Areas with predominant development of hydrothermal autometamorphism, the physical conditions of which usually do not correspond to the conditions for the formation of chrysotile asbestos, are also of little promise for exploration. After these exclusions, the area for searching for "blind" ore bodies still remains enormous. Specific localization points "blind" deposits can be identified only taking into account the presence of favorable and unfavorable combinations of tectonic faults and fault zones (see article). The main structural criteria for searching for "blind" deposits outlined in the article do not cover all the issues of the complex pattern of distribution of chrysotile asbestos deposits in the body of the Bazhenov massif of ultrabasic rocks, the knowledge of which can facilitate the search. Some of these issues are only touched upon in this work, while others can only be resolved after further accumulation of factual materials. These include issues of changes in the structure of the ore field with depth and searches for "blind" deposits of the second and subsequent tiers. It is necessary to study in detail the dependence of the localization of chrysotile asbestos deposits on the composition of primary rocks and changes in the physicochemical composition of hydrothermal solutions. The development of these issues is a necessary matter for the near future.

The study of inclusions in minerals is of great theoretical and practical importance. It allows us to more fully decipher the genesis of minerals, and consequently, to more correctly carry out an industrial assessment of their deposits. The study of inclusions in minerals that are raw materials for the optical industry, and, in particular, in Iceland spar, is especially important, since it reveals the nature of the main defects that prevent the use of crystals of these minerals for practical purposes. Iceland spar contains widespread solid, liquid and gas-liquid inclusions. This article highlights the results of the study of solid inclusions. The study of solid inclusions allows us to clarify a number of essential issues of the genesis of Iceland spar, as well as to explain the nature of defects in the optical material.

At present, qualitative and quantitative spectral analysis are being introduced into geological exploration in the search for and exploration of various fossils in order to study the material composition of host rocks, mineralization zones, minerals and ores, to study the distribution of rare and trace elements in various types of igneous and sedimentary rocks, as well as to solve other analytical problems. Particular attention should be paid to complete spectral analysis, which can simultaneously determine several dozen chemical elements using a spectrogram obtained by evaporating a 30-40 mg sample of the test sample in an electric arc between carbon electrodes (the test substance is placed in the recess of the lower electrode). The versatility and value of this research method are determined by the speed and the possibility of determining a large number of chemical elements and their content without the use of complex auxiliary equipment. In this case, the method is based on simple and accessible techniques of spectral analysis. In spectral analysis, quantitative determination is associated with an assessment of the intensity of the spectral lines of the elements being studied. The method of weakening lines using a logarithmic sector or filter uses visual determination of the intensity of spectral lines. We have carried out a number of experiments that have allowed us to evaluate the capabilities of the above method and, using nickel and cobalt as an example, to show the higher accuracy of simplified and rapid quantitative determinations of elements in the same samples.

In the process of studying mineral deposits, sampling occupies a prominent place in terms of the volume of work and cost of funds. The study shows the enormous potential for reducing the number of samples and chemical analyses by using a rational sampling technique. The patterns established by the time of operational exploration and especially by the period of stope extraction, as a rule, make it possible to sharply reduce the number of samples and chemical analyses. The number of samples can be reduced by the thickness, strike and dip of ore bodies, while the sampling error remains virtually unchanged, and the cost of funds and the volume of work during sampling are sharply reduced. The proposed sampling technique, based on the structural patterns of ore deposits, leads to significant improvements in the geological mapping of ore deposits. The allocation of industrial grades and varieties of ores will facilitate and accelerate the study of mineral deposits and, in some cases, will provide the opportunity to use the most economically advantageous sampling technique - sampling by ore types.

The emergence of drop analysis as an independent analytical method dates back to 1920. This method, which allows working with a minimum expenditure of reagents and time, was first developed in the Soviet Union by N. A. Tananaev. Drop analysis is one of the methods of microchemical analysis. However, this method can achieve the accuracy inherent in colorimetry in general only in certain rare cases. When determining on a drop plate, colorimetric comparison is much more difficult. Particularly difficult is the analysis in small test tubes. The problem of determining small quantities of elements attracts the attention, as is known, of specialists in various fields of knowledge, including geologists. The proposed method of semi-quantitative determination of zinc based on the drop analysis method was developed by us at the end of 1952. It is aimed at obtaining more reliable indicators that provide a quantitative assessment of the element being studied.

"Mapping of limestones is the first stage of polymetallic exploration for deposits of the substitution type in limestones and skarn polymetallic ores of the Tetyukhin type. Geological mapping, as is known, does not encounter any particular difficulties in areas of good rock exposure. Where rocks are covered by modern deposits of even small thickness and vegetation is developed, geologists are forced to resort to mining. For mapping in closed areas, geophysical exploration methods are increasingly used, in particular, magnetic exploration, electrical exploration, T-survey and other methods. However, the use of these methods is often limited by the small difference in the physical properties of rocks. As a component of the complex in geophysical work for mapping limestones, the carbonate survey method is proposed. The carbonate survey method, as a quantitative method of rock analysis, can serve as a methodological basis for studying mechanical dispersion halos. Its use for this purpose will provide an opportunity to better understand the laws of dispersion and ore components.

Plumbometric survey is widely used in prospecting for lead deposits in Central Kazakhstan. Work carried out at several polymetallic deposits in Central Kazakhstan in 1951-1953 established the possibility of significantly simplifying the sampling and processing methods. A simplified method for sampling and processing metallometric samples is proposed for prospecting for lead deposits, which consists of selecting a class smaller than 0.1 mm by sieve analysis, which is directly sent for analysis. This method significantly speeds up, simplifies and reduces the cost of metallometric survey work. The applicability of the described method should be tested at other deposits, where, during the formation of eluvial-deluvial deposits, minerals containing a valuable component pass into eluvium and deluvium in the form of ocher and finely dispersed formations. In 1954, the author demonstrated the applicability of this method in the conditions of Central Kazakhstan when analyzing samples from eluvium-deluvium for zinc, copper and molybdenum.

One of the diagnostic features by which the color of a mineral in powder is established is a scratch obtained on an unglazed porcelain plate (biscuit). The mineral scratch can also be used for chemical testing using the method of grinding with a solid chemical substance. It is also important to test the mineral scratch for decomposition in acids and alkalis. In the mineralogical practice of the Leningrad Mining Institute, the determination of minerals by the method of grinding a slcratch and chemical reactions on the mineral scratch is widely used. In macroscopic diagnostics of minerals, three methods are distinguished: 1) visual observation with the naked eye by the appearance of the mineral, i.e. the morphology and optical properties (color, luster, transparency and opacity of mineral individuals) are established; 2) visual determination with testing of the mechanical properties of minerals - hardness when scratched, brittleness when crushed, cleavage and fracture when splitting, the ability to be forged when flattened and obtaining a scratch on a porcelain plate; 3) chemical tests of the mineral or its scratch. Simultaneous use of these three methods allows for rapid diagnostics of minerals. The methods are applied in the specified sequence. Comparison of the color and luster of the scratch with the color and luster of the mineral helps in identifying the mineral. The proposed work provides a definition of those minerals that give a characteristic decomposition when dissolving or grinding the scratch, and minerals that are easily identified by film reactions. Diagnostics of minerals by scratch line and chemical reactions is given by classes, and within a class, minerals are arranged alphabetically.

Testing minerals with a blowpipe has its own history. When searching for ores, Russian mining engineers constantly used this method, developing and improving it. The most basic test with a blowpipe consists of heating a mineral fragment in order to study its behavior at high temperatures. Fusibility is the most important feature in determining minerals. The existing scale of mineral fusibility is satisfactory. However, it is better to take the following minerals as standards for the scale: No. 2 - halite (800°), No. 3 - grossular, fluorite, albite (1100°), No. 4 - nepheline or muscovite (1200-1250°), No. 5 - orthoclase, microcline or talc (1300-1350°), No. 6 - beryl (1410°) or serpentine (1450°). Determination of melting point is possible with an accuracy of up to +20° if it is carried out on rods prepared from dough converted into mineral powder. In this case, rods from the pyroscopes of the State Porcelain Factory prepared in the same way should be taken as standards. The melting point of the pyroscope scale numbers is given in the table. Clarification of the melting point is especially important for silicates. The melting points of many minerals are given in the first volume of the Reference Tables of Physical Quantities of the Technical Encyclopedia (1935).

When developing disturbed areas of coal deposits, it is often necessary to deal with the assignment of exploratory or opening mine workings on a displaced wing of the seam. When a fault device encounters mine workings driven along the seam, one wing of the seam, carrying these workings, is a known wing in the solution of the specified problem, and the other is a displaced wing relative to the known or displaced wing. The solution of this and other geometric problems when working on disturbed areas - before exploration or opening of the sought (displaced) wing - is based on the assumption that the displaced wing is parallel to the known wing. Before solving the problem, it is necessary to establish the type of displacement encountered and select the direction of the working opening the displaced wing. To do this, it is necessary to know the vector of the "true" relative displacement of the displaced wing or the amplitude of the displacement in a certain direction, established by exploration. Strokes, furrows, potholes and crush halos on the plane of the fault device, as well as wing turns near cracks can serve as signs indicating the direction of movement of the "lost" wing, and can be used to determine the type of displacement and select the direction that opens the desired wing of the working.

When drawing detailed geological maps with a hatched and, moreover, complex legend, difficulty usually arises in selecting symbols that ensure a sharp separation of individual geological horizons. Often, even in important publications, one can encounter unsuccessful so-called "blind maps". This reduces the quality of the book's design and interferes with the clear perception of the illustrations. The selection of the most successful symbols to a certain extent always remains a matter of art and experience for map compilers and draftsmen. But in this matter, knowledge of some basic, simple provisions that allow one to avoid at least elementary errors when drawing maps can also help. This article outlines a number of general principles for combining symbols that should not be overlooked in the interests of the greatest clarity of maps. Hatched symbols can be arranged in a row with increasing or decreasing density of dark coloring. For this, it is advisable to use a combination of two, three or four of the above-mentioned methods of contrasting - differences in thickness, distance and direction between lines (or icons). The greatest effect is achieved by using all four differences, in particular the proximity of black and white. These differences must be combined so that each new addition to a given designation acts in one direction. The use of dotted lines and figured signs is subject to the same laws, i.e. they must also combine differences in direction, distance, and thickness or boldness of the signs.