Peculiar Composition Research Articles

Epidemiology of Age-Related Macular Degeneration in the Republic of Bashkortostan (Clinical and Statistical Analisys of the “Ural Eye and Medical Study”)

Purpose. Analysis of the AMD prevalence in the Republic of Bashkortostan, depending on the disease stage, gender and the nature of the respondent settlement. Methods. A population-based study of Republic of Bashkortostan residents “Ural Eye and Medical Study” was conducted on the basis of the State Budget Institution “Ufa Research Institute of Eye Diseases of the Academy of Sciences of the Republic of Bashkortostan”. There were 5899 participants in the study, 2581 (43.7 %) were men, 3318 (52.3 %) were women. There were 2501 urban residents (42.3 %), rural residents — 3398 (59.7 %). Study design: cross-sectional one-stage analytical research. Statistical data analysis was performed using the IBM SPSS statistic application package. Results. AMD was diagnosed in 550 individuals (11.5 %): early stage — in 392 (7.9 %), intermediate — in 119 (2.4 %), later — in 39 individuals (0.8 %). The number of men with AMD was 210 (10.8 %), women — 340 (11.4 %). Among men, an early stage was observed in 144 (7.4 %), intermediate — in 52 (2.7 %), later — in 14 individuals (0.7 %). Among women, early AMD was observed in 248 (8.3 %), intermediate — in 67 (2.2 %), later — in 25 individuals (0.8 %). The number of urban residents with AMD was 194 individuals (9.7 %), rural residents — 356 individuals (12.1 %). At the same time, among urban residents, an early stage was observed in 138 (6.9 %), intermediate — in 43 (2.2 %), and later stage — in 13 individuals (0.6 %). Among rural residents, the early stage of AMD is in 254 (8.6 %), intermediate — in 76 (2.6 %), later — in 26 individuals (0.9 %). Conclusion. The prevalence of AMD in the Republic of Bashkortostan according to the “Ural Eye and Medical Study” is 11.1 %, which exceeds the global figure. The lack of prevalence of the AMD among women (among women — 11.4 %, among men — 10.8 %) is a distinctive feature for this region. The prevalence of this pathology among rural residents (12.1 %), among urban (9.7 %). The influence of population characteristics for the prevalence of AMD in regions with a peculiar ethno-cultural composition, geographical features.

Zakarpatskiy perlit as component of mineral woven fabric material

Thanks to the peculiarities of the chemical composition and structure, perlite has received application for manufacturing building materials - thermal insulation and ceramic
 Results over of research of the silicate systems with transcarpathian perlite as raw material for making of mineral astringent material are driven. The features of the chemical-mineralogical composition, phase transformations during burning and astringent properties of material at the use of perlite from Beregovsky deposit in composition initial raw material mixtures are shown.
 To determine and optimize raw material stock at the production of mineral binder material of low-temperature roasting type of natural or romanticum, a computer program "RomanCem" was used.
 After burning with a maximum temperature of 1100°C, the test of the binder material from the investigated 3-component mixtures with Transcarpathian perlite is characterized by differences in phase composition and properties.
 When using for the manufacture of mineral binder material of low-temperature firing of a gypsum natural or romantic cement 3-component mixtures based on the limestone system - perlit - clay, the content of Transcarpathian perlite is possible from 4 to 22 mass. %.

Peculiarities of Structure and Phase Composition of Ternary NiMn–NiTi Alloys with a Quasi-Binary Cross-Section

The influence of a chemical composition on the phase composition, stability, and crystal structure type of the austenitic and martensitic ternary NiMn–NiTi alloys with a quasi-binary cross-section is analyzed. The temperature-concentration limits of their existence are determined. It is found out that doping of these alloys with titanium decreases the critical temperatures of thermoelastic martensitic transformations compared to those of the basic binary intermetallic compound NiMn. In the alloys, doped with more than 15 at.% titanium, phase decomposition is observed, followed by the formation of titanium-rich (Ni3Ti) ternary precipitates of the 4H-HCP type, which form a Widmanstatten substructure.

Peculiarities of the molecular composition of heterochromatin associated with pronucleoli in mouse embryos

The nucleus of pre-implantation mammalian embryos is characterized by peculiar structural organization. At the initial stages of cleavage, the nucleus of the embryo contains the so-called nucleolus precursor bodies (NPBs) or pronucleoli rather than functionally active nucleoli. The NPBs are fibrillar electron-dense structures inactive in RNA synthesis. The vast majority of NPBs are surrounded by a ring-shaped zone of transcriptionally inactive heterochromatin. Intriguingly, these zones contain not only tri-methylated histone Н3K9me3 as an epigenetic mark of repressed chromatin but also acetylated histone H4K5ac, a well-known marker of active chromatin. Immunocytochemical data suggest that the molecular composition of this ‘ring heterochromatin’ in mouse embryos changes during the realization of embryonic genome activation events, as well as during artificial suppression of transcription. In zygotes, some factors of mRNA biogenesis including splicing factor SC35 (SRSF2) and basal transcription factor TFIID are detectable in the ring chromatin. At later stages of development, other nuclear proteins such as Y14, a core component of the exon-exon junction complex (EJC), as well as the proteins involved in chromatin remodeling (ATRX, Daxx) are also detectable in this area. A typical component of the ‘ring heterochromatin’ is actin. Anti-actin immunocytochemical labeling is most expressed at the two-cell cleavage stage after activation of the embryonic genome. Indicatively, the molecular composition of the ‘ring heterochromatin’ associated with different NPBs may differ significantly even in the same nucleus. This seems to reflect the functional heterogeneity of morphologically similar NPBs according to their competence to the process of nucleologenesis. Here, we discuss briefly some peculiarities of the molecular composition and possible functions of the NPB-associated heterochromatin in mouse early embryos.

ASSESSMENT OF CARCINOGENIC RISK TO POPULATION HEALTH DUE TO HIGH ARSENIC CONTENT IN DRINKING ARTESIAN WATER OF THE NORTH DAGESTAN

The northern part of the Republic of Daghestan is characterized by high levels of arsenic in artesian drinking water due to peculiarities of the chemical composition of the water-bearing plateaus. The concentrations of arsenic in water samples ranged from 0.01mg/l to 0.5 mg/l. According to current guidelines for arsenic of 0.01mg/l, the excess in the level of arsenic in water was detected to 20-fold or more in 12 villages with the total population of 15 827 people. To evaluate the cancer health risks from exposure to arsenic we used еру risk assessment method. Lifetime individual cancer risks were shown to be at the minimum concentration (0.01mg/l) - 4.3E-4; at maximum concentration (0.5 mg / l) -2.1E-2, respectively, with a mean of 0.14 mg/l - 6.0E-3. The cancer health risks results were found to be higher than permissible value of 1∙10-6. For the exposed population (309,700 people) annual population cancer health risks ranged from 1 to 94.8 additional cases of possible occurrence of cancer. The results of this study revealed areas with high levels of arsenic in drinking water and determined the exposed portion of population to recognize the implementation of measures for the mitigation of risks.

MINERAL WATERS OF THE SOUTHERN REGION OF UKRAINE

The peculiarities of formation, macro- and microcomponent composition of mineral waters of the Southern region of Ukraine and prospects of their further researches with the purpose of development of scientific principles their of effective practical use are considered.

КАРБОНАТНЫЕ КОРЫ НА ФАСАДАХ ЗДАНИЙ И СООРУЖЕНИЙ ГОРОДА ТЮМЕНИ: РАЗНООБРАЗИЕ И ФАКТОРЫ ФОРМИРОВАНИЯ

Актуальность работы. Карбонатные коры, наросты и выцветы, формирующиеся на фасадах различных зданий и сооружений в результате выщелачивания компонентов строительных материалов, таких как цемент, бетон, известняк, являются наиболее распространенными видами техногенного минералообразования в условиях городской среды. В отличие от непрочных сталактитов и сталагмитов, формирование которых наблюдается только в определенных условиях, подобные образования широко распространены. Развитие карбонатных кор, наростов и выцветов на фасадах зданий не только свидетельствует о процессах разрушения связующих компонентов строительных конструкций, но и оказывает негативное воздействие на эстетическую привлекательность объектов городской архитектуры. Натёчные образования кальцита заполняют микротрещины и неровности поверхностей облицовочных материалов, что приводит к интенсификации процессов разрушения и требует проведения дорогостоящих мероприятий по очистке фасадов. Исследования, посвященные изучению карбонатных новообразований на фасадах различных зданий и сооружений, немногочисленны. Цель работы: выявление особенностей минерального состава, строения и возможных механизмов образования карбонатных кор и натеков, формирующихся на фасадах зданий и сооружений города Тюмени в различных условиях; определение факторов, способствующих данному явлению. Методы: выявление и систематизация объектов городской архитектуры, подверженных процессам формирования карбонатных новообразований, поляризационная и инвертированная микроскопия в прозрачных шлифах, СЭМ-ЭДС, рентгеноструктурный анализ. Результаты. Карбонатные коры и натеки существенно различаются по особенностям строения, минеральному составу и вероятным механизмам формирования в зависимости от конкретного местоположения. Четко разделяются коры, развивающиеся на вертикальных и горизонтальных поверхностях: первые – плоские, достаточно тонкие и имеют слоистую структуру, вторые – плотные и характеризуются глобулярным строением. Формирование карбонатных новообразований происходит при значительном участии живых организмов, а процессы биогенного осаждения кальцита происходят синхронно с хемогенным. Четких связей между возрастом или местоположением конкретных объектов и интенсивностью формирования карбонатных кор не выявлено; соответственно данный процесс скорее обусловлен конструктивными особенностями конкретных сооружений и качеством строительных материалов.

Effect of fluoride-mediated transformations on electrocatalytic performance of thermally treated TiO2 nanotubular layers

Abstract The peculiarities of morphology, crystalline structure and chemical composition of TiO 2 nanotubular layers (TNT) and TiO 2 nanoparticulate (NP) layers obtained by fluoride-mediated transformation of TNT have been described in the present paper. The annealing of amorphous TNT in a confined space under limited air access conditions leads to TNT-to-NP transformation accompanied by fluorine doping of the titania matrix as supported by X-ray photoelectron spectroscopy investigations. The collapse of tubular structure as well as the formation of nanoparticles was confirmed using scanning electron microscopy (SEM), X-ray diffraction (XRD) and Raman spectroscopy. Electrocatalytic activity of both TNT and NP electrodes toward oxygen reduction reaction (ORR) has been examined by cyclic voltammetry (CV). The positive shift of ORR wave of the NP layers in comparison with TNT makes the NP-based electrodes more suitable for oxygen reduction. The improved activity of the NP electrodes is attributed to the increased concentration of redox active Ti 3+ species owing to fluorine doping of TiO 2 which plays a crucial role in electroreduction of oxygen molecules.

Territory and Population of the Stalingad Region in 1939-1944

Introduction. The Stalingrad region was founded on the 5th of December 1936. In 1939-1944 the territory and population of the region underwent changes. It included a number of areas of the Volga German ASSR and the Kalmyk ASSR eliminated in 1941-1943. The Astrakhan district was transformed into an independent region, the Germans and the Kalmyks were deported to the eastern regions of the country. Methods and materials. The author of the article uses statistical materials of the All-Union Population Census of the USSR of 1939 and the information and statistical reference book Stalingrad region (1939-1943). Figures and facts. A comparative historical method is widely used to reveal the peculiarities of the national composition of the population of the Stalingrad region and its neighboring regions, and to show the changes that took place in different areas of the region during 1939-1944. For the first time in research literature, 5 groups of rural areas of the region are distinguished. Analysis. The national composition of the population of Stalingrad, Astrakhan and rural areas of the region is investigated, and a comparison with neighboring regions is conducted. Representatives of more than 80 nationalities lived in the Stalingrad region, among them Russians (87.6 %), Ukrainians (3.6 %), Kazakhs (3.2 %), Tatars (2.8 %) and Germans (1.0 %) prevailed. Special attention is paid to the change in the territory and composition of the region’s population after the annexation of 7 areas of the eliminated Volga German ASSR in 1941 and 2 areas of the eliminated Kalmyk ASSR in 1944 and the deportation of Germans and Kalmyks to the eastern regions of the country. Results. The war led to a change in the national composition and a substantial reduction in the number of residents in the region. It took about 20 years to overcome the consequences of the war and deportation to restore the population of the Stalingrad region.

Characterization of building materials from the Anfiteatro Flavio (Pozzuoli, southern Italy): a mineralogical and petrographic study

This work is the result of a geoarchaeological investigation on the Anfiteatro Flavio, one of the most important archaeological sites in the Campania region (southern Italy), situated in an area of great geological and archaeological interest, the Campi Flegrei volcanic field. The aim of this research was to characterise building stonesemployed for structural use, focusing on the type of materials and their provenance. The mineralogical-petrographic characterization of 27 samples from corbels and pillars involved X-ray powder diffraction analyses (XRPD), thin section optical microscopy observations (OM) and energy dispersive spectrometry microanalyses (EDS). The results revealed that the source materials are represented by two distinctive trachytic/phonolitic lava deposits. Pillar light grey block samplesare made of a feldspar-phyric (F-p) lava type that shares many petrographic and mineral chemical features with the Campi Flegrei Accademia lava dome, cropping out in the immediate proximities of the Anfiteatro Flavio. On the other hand, pillar grey block and corbel samples are made of an alkali feldspar and sodalite-phyric (KS-p) lava that has been correlated to an Ischian lava deposit based mainly of the peculiar composition of the observed amphibole crystals. Previous data attesting for the use of the Piperno welded tuff for the pillar grey blocks were likely driven by the “eutaxitic-like” fluidal oriented texture and by the alveolitization alteration displayed by the samples. This however does not exclude that the Piperno had been employed as a building stone for other structural elements of the amphitheatre. The use of the Ischia lavas as an exported building material had been never reported before, possibly suggesting that current knowledges about the use and trade of building materials in the Campania area during the Roman period need to be reconsidered.

Promising Directions for the Stabilization of Ferroalloy Production Slags

In this paper the analysis of the processes for spontaneous decay of slags from the production of refined ferroalloy grades is performed. It is shown that the main reason for the decay is the formation of a dicalcium silicate in highly basic melts with CaO / SiO2 ratio of 1.5-3.1. Based on the performed studies, three main promising directions for the stabilization of slags of ferroalloy production have been formed. First direction is the replacement of the calcium cation (or transformation) in a dicalcium silicate, for example, with the magnesium cation or the production of non-decaying compounds of the gehlenite type (2CaO·Al2O3·SiO2), mainly due to the application of phase composition peculiarities of the waste rock for ferroalloy raw materials. Second direction is the reduction of the dicalcium silicate content with a decrease in the ratio of CaO / SiO2 in the slag less than 1.4, due to the separation of the silicothermic reduction process into two stages, obtaining in the first stage a low-basic (CaO / SiO2 = 1.3-1.4) non-decaying tailing slag, and on the second one - highly basic return slag (1.8-1.9), which is used in the first stage of this technological chain. The third direction is the replacement of the SiO anion of dicalcium silicate with other anions, for example, ВО by means of small additions of calcium borate, colemanite, etc. A possibility for stabilization of ferroalloy production slags with obtaining of construction crushed stone corresponding to the requirements of TU 0798-69-00186499-2014 "Crushed stone and sand from ferroalloy slags. Technical conditions», is shown experimentally.

Мороженое как средство доставки Lactobacillus acidophilus

Ice cream is a product with specific composition and properties that are highly valued by a wide range of consumers. Peculiarities of ice cream composition and production technology make it possible to consider the product as a promising carrier and means of biologically active compounds and useful microorganisms supply. The article reveals morphological, biochemical, physiological, genetic and technological characteristics of L. acidophilus. It systematizes information on the existing methods used for production of ice cream with L. acidophilus. The author shows the influence of various forms of the introduced acidophilus bacteria and methods for their adaptation on ice cream quality indicators. The article provides the data on the properties of ice cream fermented and unfermented with this cultures. It reveals information on the impact of various technological, physicochemical and physiological factors on the survival capacity of pure culture L. acidophilus and its combination with other microorganisms in the process of ice cream production, storage and consumption. The author considers perspective ways of acidophilic ice cream production using various combinations of prebiotics, dietary fibers, replacing refined sugar with honey and unrefined sugars, introducing whey proteins, fruit puree, grain additives and other ingredients. The article presents the data on the influence of functional components on the production process and properties of ice cream containing acidophilus bacteria. The author systematized information on ice cream production using different strains of L. acidophilus and Bifidobacterium spp. replacing cowʼs milk with vegetable analogues. Methods for producing ice cream with L. acidophilus and other starter cultures, including yogurt cultures are described. The review justifies practicability of L. acidophilus application in ice cream production. It reveals trends and issues in the area of functional use ice cream production.

Peculiarities of composition and vertical distribution of centric diatoms in the Klyuchik Lake (Nizhny Novgorod Region)

The composition and development of phytoplankton of highly mineralized Lake Klyuchik (Nizhny Novgorod Region) were considered. The lake is unique of having a distinct ecotone on hydrochemical parameters. The prevalence of diatom algae, which are dominant in the number of species (46% of the total species composition) and abundance indices, was revealed. The vertical distribution of algae development was the most heterogeneous in the ecotone zone. In the bottom layers of the ecotone there was a mass development of the centric diatom Cyclotella distinguenda Hustedt with uniquely high abundance (several ten million cells/l) and biomass (more than 130 g/m3).

Efficiency of Antiscalants in Industrial Cooling Water Systems

In many industrial operations formation of deposits on heat exchanger surfaces and other cooling systems is a persistent problem. These deposits contain mineral scales (CaCO3, CaSO4, Ca3 (PO4)2, CaF2 etc.), corrosion products (Fe2O3, Fe3O4, Cuo etc.), particulate matter (clay, silt etc.) and microbiological mass. Deposition of these materials on heat exchange surfaces lead to loss of system efficiency, overheating, unscheduled shutdown and ultimately failure of heat exchangers. In cooling and boiler water systems, these deposits normally accumulate in low circulation areas and may become immobilized during upset conditions resulting in buildup of deposits on heat exchangers. An effective cooling water treatment must control scale, particulate matter and corrosion. Over the years, a variety of antiscaling agents have evolved including acid/chromate, zinc/chromate, stabilized phosphonate, phosphate/zinc/polymer and all organic. Phosphonates are excellent calcium carbonate inhibitors or antiscalants which reduce the scale formation in cooling water systems. Determination of efficiency of these antiscalants is also important before using them. Techniques (Boffardi, ONGC) presently used for determining their efficiency do not provide consistent results, these methods are time consuming and also difficult to execute. Industries are facing problem in finding the optimum dosage ofantiscalant in cooling water systemswith a peculiar composition. So, a technique based on the theoretical considerations has been given herein, which produces consistent results in an easy way and requires less time to perform using cooling system water.

Nitrogen behavior in the shallow groundwater–soil system within agricultural landscapes

The research is devoted to the analysis of the changes in the chemical composition of shallow groundwater within the agricultural landscapes of the Poyang Lake area taking into account the peculiarities of soil composition. The analysis is based on field data collected during 2011–2017 by the sampling of the shallow groundwater from the private and public wells and adjoining soils. Correlations between the content of the N-compounds and the Eh values in autumn as well as a relationship of the NH4+ concentration with the DOC content reflect the processes of the organic matter transformation in the aquifer. Correlations between the N content in the upper soil horizon and the concentrations of the N-compounds in the shallow groundwater indicate a strong connection of the origin of the groundwater chemical composition with the soil composition.

Особенности элементного состава тысячелистника обыкновенного в условиях техногенного загрязнения

Особенности элементного состава тысячелистника обыкновенного в условиях техногенного загрязнения

Peculiarities of structure and phase composition of V-Ti-Cr alloy obtained by sintering technique

Alloy of the V-Ti-Cr system is a promising material exploited under high radiation and in corrosion environment. We sintered V-4.9Ti-4.8Cr alloy from particles with original average size of 30, 280 and 200 μm, respectively for vanadium, titanium and chromium powders, by pressing of the powder mixture and its further sintering. The studies were undertaken using the methods of X-ray structural analysis, scanning electron microscopy with an energy dispersive analyzer and transmission electron microscopy. It was established that the structure of the alloy represented matrix grains (BCC solid solution), along the boundaries and at junctions of which the groups of oxycarbonitride particles of V, Ti, Cr (C,N,O) type of the variable elemental composition were arranged. The particles possessed a plate-like (0.4 x 2.0 μm) and rounded (0.5 μm) shape. The solid solution of the alloy was heterogeneous by concentration. This was evidenced by the complications of the diffraction patterns obtained from the corresponding sections of the structure. These were cords of main reflexes, satellites and emergence of a moire banded contrast in separate sections of the sample. Inside the matrix grains, there were nanoparticles (15 μm) of carbide V55Cr25C20, being a source of elastic internal local stresses.

Investigation of peculiarities of economic use and qualitative composition of land resources of agricultural enterprises of Lviv region

The paper outlines the research of main features of functioning of agricultural enterprises in Lviv region based on statistics and selected data of State Land Agency of Ukraine. The research shows the decline in the number of agricultural enterprises related mostly to insufficient land relations formed in the country. The author argues that substantial changes occurred in the structure of land use and land ownership of Lviv region in the process of land reform. In particular, the lands granted by residents to forestry or agricultural enterprises prevail in the structure of land resources of the oblast. Non-public agricultural associations prevail among agricultural enterprises – users of land resources. In terms of functional use, the land resources of agricultural enterprises mostly consist of arable lands. The structure of crop areas represents the real state of affairs and determines the specialization of agriculture in Lviv region taking into account the zonal soils and climate conditions, market conditions (internal and external), social and economic situation and environmental requirements to forming of agricultural landscapes. Land resources of agricultural enterprises in Lviv region show orientation of agricultural production on crop farming with prevailing industrial crops based on the chemical composition and quality of soils. The paper examines the qualitative composition of lands in the region and the peculiarities of maintaining their fertility. The author argues that soils mineralization substantially influences the quality of the grown agricultural products. On this basis the paper reveals the problems and obstacles of the management of land resources use by agricultural enterprises. Their overcoming should become the primary task towards strategic maintenance of efficient functioning of agricultural enterprises.

Peculiarities of the component composition of ether oils of some representatives of Lamiaceae Lindl family in the conditions of forest-steppe of Ukraine and estimation of their biological activity

The purpose of the research is to study the biochemical composition, physical-and-chemical peculiarities of ether oils of dragonhead, hyssop, monarda and to determine their biological activity. Materials and methods. Vegetative raw materials of dragonhead, hyssop, monarda were taken during the flowering period. The component composition of ether oils was studied at a gas chromatograph “Crystal 2000” with a flame-ionization detector. Components of ether oils were identified by the time of substance keeping of the standards of Fluka, Merck, Sigma companies. The allelopathic activity of ether oils, citral, thymol, pinecamferol was studied by the bio-tests method. Results. The component composition of ether oils of scarlet monarda (Monarda didyma L), Moldavian dragonhead (Dracocephalum moldavicum L.), hyssop (Hyssopus officinalis L.) as valuable aromatic plants of polyfunctional value was studied and their physical-and-chemical parameters were determined. The main component of ether oil of hyssop plant was pinecamferol (84.68 %). The following compounds of terpenic nature as citral (49.9 %), geranilacetal (43.9 %) are found in ether oil of Moldavian dragonhead. Terpenic compounds of ether oils of scarlet monarda were represented by aromatic alcohols of thymol - 41,56 %. Growth processes of spring barley seedlings were slowed down while using oils synthesized from the vegetative material of all studied varieties at a concentration of 0.1 mcl (by 8.4-86.0 %), besides that hyssop oil had the least inhibitory effect. Concentrations of 0.1-1.0 mcl (92.74-98.85 %) especially in the variants with Moldavian dragonhead oil had the maximum impact on the development of garden-cress. Conclusions. The connection of biological activity with the component composition of ether oils of studied representatives and their chemically pure basic components was analyzed. The high biological activity of the studied substances, which may be a regulator of the structure and functions of individual components of the ecosystem under natural conditions, was proved. The received results indicate the prospect for further study of the peculiarities of ether oils of three varieties of studied plants of Lamiaceae Lindl family - Hyssopus officinalis L., Monarda didyma L., Dracocephalum moldavicum L., where aromatic substances dominate

ПЕТРОХИМИЧЕСКАЯ ХАРАКТЕРИСТИКА КОР ВЫВЕТРИВАНИЯ ОЛЬХОВСКО-ЧИБИЖЕКСКОГО РАЙОНА

Актуальность исследования обусловлена необходимостью расширения и укрупнения минерально-сырьевого потенциала золотодобывающей промышленности. Целью исследования является получение новой дополнительной информации о строении, зональности, минеральном составе кор выветривания Ольховско-Чибижекского района, а также выявление петрохимических критериев, определяющих условия повышенных концентраций золота в продуктах гипергенеза. Объекты: остаточные и переотложенные коры выветривания каолинового и гидрорслюдисто-каолинового состава Ольховско-Чибижекского района (Восточный Саян). По условиям залегания, в пределах района выделяются линейные и линейно-площадные типы кор выветривания, преимущественно золотоносные. Методы. Количественное определение основных породообразующих элементов по профилю коры выветривания проводилось методом рентгенофлюорисцентного анализа при помощи энергодисперсионного рентгенофлуоресцентного микроскопа (ЭДРФ, модель HORIBA XGT­7200). Для характеристики процесса корообразования и количественной его оценки были использованы коэффициенты выветривания. Был проведен анализ распределения породообразующих элементов по профилю коры выветривания с выделением потенциально золотоносного горизонта. Результаты. В пределах Ольховско-Чибижекского района коры выветривания развиты довольно широко. Среди них выделяются остаточные и переотложенные. Остаточные коры выветривания мел-палеогенового возраста на изучаемой площади района развиты по кислым и средним породам ольховского комплекса, а также карбонатным образованиям чибижекской свиты; представлены они линейным и линейно-площадным морфологическими типами; продукты выветривания сложены глинистым, песчано-глинистым и дресвяно-щебнистым материалом, с преобладанием тонкодисперсной глинистой фракции; эти отложения в значительной степени лимонитизированы и карбонатизированы; по составу остаточные коры выветривания относятся к каолиновому и каолинит-гидрослюдистому типу. Установлено, что остаточные коры выветривания характеризуются развитием полного профиля, в составе которого выделяются зоны: дресвяно-щебенистая, монтмориллонит-гидрослюдистая и охристо-каолиновая. В результате проведенных исследований изучены особенности минерального состава остаточных коры выветривания Ольховско-Чибижекского района; дана минералого-петрохимическая характеристика изучаемых кор выветривания, установлен характер изменения коэффициентов выветривания и особенности распределения золота в вертикальном разрезе кор выветривания, определены геохимические критерии накопления золота в продуктах коры выветривания. Установлено, что повышенные содержания золота приурочены к нижней части верхней охристо-каолиновой зоны с высокими значениями коэффициента ферритизации, аллитизации и коэффициента окисления и минимальными значениями коэффициента выщелачивания. И наоборот, низкие содержания золота характерны для менее выветрелых пород с минимальными значениями коэффициентов ферритизации, аллитизации и окисления.