Vol 51 Iss. 2

The compilation of geochemical maps should be preceded by a clear formulation of the concept of geochemical map. As it is known, there are different points of view and different understandings of map construction and practically there is no experience in making polyelemental geochemical maps.Under geochemical the authors understand a map that reflects the content, character of distribution and form of finding a wide range of chemical elements in the bedrock. Such a map should be one of the main in the creation of metallogenic and prognostic-geological maps ...

The study of distribution patterns of element concentrations in rocks, ores and minerals is one of the main problems of geochemistry. In recent years, more and more works appear, where to the elucidation of distribution patterns are approached from the point of view of probability theory. Most studies are based on the data of chemical and quantitative spectral analyses of samples of eruptive rocks. So far, the huge material of semi-quantitative spectral determinations has been little used for this purpose. Meanwhile, semi-quantitative spectral analysis at the modern level of its performance for a number of elements can provide important geochemical information ...

As is known, the main, if not the only, method of prospecting for gold deposits until the last decade was a schlich survey. Since 1956, in Eastern Transbaikalia and then in other areas along with the schlich survey are increasingly used geochemical methods, which became possible due to the use of highly sensitive adsorption-spectral method of analyzing samples for gold. Then electrochemical-spectral, double-arc spectral methods were proposed, among which the electrochemical-spectral method is the most widely used. All these analytical methods were developed for the analysis of lithochemical and, to a lesser extent, biochemical samples. For hydrochemical samples there are still no reliable express highly sensitive methods of gold determination. The works of VITR, Leningrad Mining Institute and other organizations have not yet left the experimental stage, although there are already some recommendations. This article is based on the materials obtained during research within the Lubavinsky ore field, as well as the materials of N. I. Safronov, V. V. Polikarpochkin and others in Eastern Transbaikalia, A. M. Grigoriev in Buryatia, L. V. Razin and I. S. Rozhkov in Yakutia ...

Assessment of the prospectivity of newly discovered areas and the choice of further direction of prospecting work in lithochemical surveys are hampered by the bulk determination of metal content in samples, which does not give an idea of the composition of ores, type of mineralization, etc. In this light, the study of the mineral composition of loose eluvio-deluvial deposits from secondary halos of dispersion is of great importance. Interesting results were obtained in the search for polymetallic deposits in Central Kazakhstan ...

As is known, the formation of secondary scattering halos in cover sediments is mainly influenced by: the primary content and distribution of metals in bedrock and their chemical and mineral composition; climatic, orographic and hydrogeologic conditions; geomorphologic structure of the area; thickness, composition and origin of cover sediments; migration ability of elements or compounds in aqueous media; the presence of media that promote the deposition of metals during their migration ...

When developing the problem of formation of eluvio-deluvial scattering halos, clarification of the role of salt and mechanical dispersion of various metals, quantitative assessment of ore occurrences by scattering halos, it is necessary to know the distribution of metal by size classes in lithochemical samples ...

The methodology of lithogeochemical survey in conditions of overlapping of bedrock by moraine formations of considerable thickness differs significantly from the methodology used in cover el in dealluvial deposits. This difference, as we found in one of the regions of the Kola Peninsula in the search for copper-nickel sulfide ores, is due to the greater importance of salt halos in scattering than mechanical ...

Geochemical methods of prospecting for deposits of fluorspar are based on the detection of secondary fluorine dispersion halos in eluvio-deluvial sediments. Elevated fluorine content in loose sediments and scattering halos are usually detected by spectral analysis, which makes it possible to determine the gross content of fluorine in samples regardless of their mineral composition ...

The copper-nickel sulfide ore deposit under consideration is located in the northern part of the Tersko-Notozersky anticlinorium, composed predominantly of Archean rocks of the Kola series. Genetically and spatially, it is associated with a multilayer intrusion of ultrabasic rocks (olivinites, harzburgites) that are significantly metamorphosed. The intrusion is a series of bedded and lenticular bodies occurring in the nuclear part of the brachianticline, composed of rocks of the Kola gneiss series ...

Distribution of mercury in Paleozoic strata of South Fergana is studied on statistical processing of 4500 semi-quantitative spectral analyses of lithochemical samples. The limit of sensitivity for all samples 1-10-5% Hg, for 250 samples (analyzed in the laboratory of the Kazakh branch of VIRG) 1-10-7% ...

Features of distribution of chemical elements in rocks are considered as a geochemical criterion in the study of magmatic and sedimentary complexes of rocks and their relationship with minerals. As it is known, geochemical studies increase the depth of search for mineral deposits. These searches are based on the study of the regularity of distribution of chemical elements in rock strata. Consequently, for geochemical prospecting it is important to simultaneously determine many chemical elements and their quantitative ratio in various rocks of separate regions, sites and zones of the investigated territory. In this case, a large number of samples are investigated. It can be hundreds, thousands and tens of thousands of analyses. The main volume of analysis is made up of rocks and loose sediments. Minerals and ores in this case represent a smaller number of determinations, but their performance can be specific ...

The choice of a rational method of concentration of microcomponents of natural waters is one of the main issues in hydrogeochemical prospecting for ore deposits. Practically the most common are several methods of concentration of trace elements: evaporation to dry residue, co-precipitation with cadmium sulfide - the method of the All-Union Institute of Technology and Exploration and the Leningrad Technological Institute and co-precipitation with aluminum hydroxide - the method of the Tomsk Polytechnic Institute. To compare these methods, the geochemical party of the Leningrad Mining Institute in one of the tin-ore mining taiga regions of the Far East from 750 samples were selected 135 for parallel analysis by three methods and about 200 - for control analyses by different methods of concentration ...

The question of the origin of hydrocarbon gases of the Khibiny and Lovo-Zersky alkaline intrusive massifs has not been finally solved so far.According to I. A. Petersilie. There are three hypotheses about the origin of hydrocarbon gases: 1) due to assimilation and processing of organic compounds of the Imandra-Varzuga Formation by the magmatic melt; 2) in the magmatic melt (in the form of gas flow they rise to the surface parts of the lithosphere); 3) in the process of intrusion formation, simultaneously with the formation of magmatic rocks ...

To date, the methods of taking into account emanation in the radiometric analysis and sampling of uranium ores have been developed in sufficient detail. For thorium and uranium-thorium ores these questions are poorly studied, because it is believed that thoron has a short half-life (TTp = 54.5 sec), so it quickly comes into equilibrium with the parent substance ...

The development of the theory and practice of the γ-method requires the study of the depth of studies in specific conditions. Depth depends mainly on the type of the γ-radiation source, the density of the medium, the size of the probe (measuring unit) and its design, the position of the probe relative to the surface of the medium under study (the presence of the intermediate medium and its properties). Experimental study of depth studies mainly refers to the method of scattered γ-radiation ...

When a narrow beam of γ-radiation passes through a substance, photons are dropped from the beam as a result of scattering and absorption. In the γ-quantum energy range of 0.03-10 Mee, which is of interest for radiometry and nuclear geophysics, the main processes leading to attenuation of the γ-quantum flux are: photoelectric absorption, coherent and Compton scattering, formation of electron-positron pairs ...

Semiconductor diodes and triodes are widely used in the practice of geophysical instrumentation, which allow to significantly increase the efficiency, reduce the size and weight of the equipment. However, semiconductor devices, having high performance qualities, at the modern level of production technology are characterized by a scatter of parameters. Therefore, when designing critical nodes of equipment it is necessary to select diodes and especially triodes according to their electrical properties. The most complete idea about amplifying properties of transistors gives the analysis of their output characteristics. Since the process of taking characteristics by points is labor-intensive, there are devices that allow visual observation of the output characteristics of transistors on the oscilloscope screen. Such devices are made in the USSR and abroad in various modifications depending on the range of solved tasks and the required accuracy of observations. Relatively universal units have a complex electronic circuit, simpler ones, as a rule, provide the possibility of only qualitative assessment of amplifying properties of transistors ...