Conditions of localization and patterns of distribution of gold-poly-metal mineralization of the Dagkesaman deposits (Lesser Caucasus, Azerbaijan)

We studied the structural-morphological types and mineral composition of ore bodies, stages of ore development and conditions of development of the deposits. The research revealed significant elements of the corresponding conditions of localization of gold-polymetallic mineralization, the most characteristic being albitophyre subvolcanic bodies and steeply-dipping damages related to them. According to the structural-morphologic peculiarities, the ore bodies should be united under three categories: 1) simple vein; 2) complex vein; 3) veinlet-impregnation types. The positions of gold ore bodies and their morphological peculiarities were found to be determined by structural factors. Presence of small ruptures, differently-oriented systems of fractures and faults, which run across the area, gentle curves of these systems and other structural elements –all of this promotes gold ore development. There research determined aureoles of ore-containing altered rocks (serialization, chloritization, kaolization and calcinations, and limonitization from hypergenical zones) and presence of zonal structure. Gold-productive areas were identified as the quartz-pyrite association with disperse gold, and especially, the second mineral association where there is a notable close paragenetic connection between noticeable gold and chalcopyrite-galena parageneis of polymetallic stage. In the process of ore development, the physical-chemical conditions have presumably changed from average deep (quartz-pyrite-sericite) to shallow (quartz-galena- sphalerite-gold ore) and close-to-the-surface (quartz-chalcocite-hematite). Gold that occurs with all the mentioned minerals of this stage has developed in the temperature interval of 220–160 °C. The study found the ores to be complex, containing the following dditional elements: Fe, Cu, S, Bi, Zn, Pb, As, Se, Te. The main fossil component is gold. Industrially valuable are also cadmium, zink, copper and silver, found in the ores. We found the following morphological types of grains of native gold: homogenous, zonal, mono-granular, spotted, which are of great significance for concluding on genesis of the deposits, prognoses, explorations and assessments.

Nonlinear reversed shear Alfvén eigenmode saturation due to spontaneous zonal current generation

General nonlinear equations describing reversed shear Alfvén eigenmode (RSAE) self-modulation via zero-frequency zonal structure (ZFZS) generation are derived using nonlinear gyrokinetic theory, which are then applied to study the spontaneous ZFZS excitation as well as RSAE nonlinear saturation. It is found that both electrostatic zonal flow and electromagnetic zonal current can be preferentially excited by finite-amplitude RSAE, depending on specific plasma parameters. The modification to local shear Alfvén wave continuum is evaluated using the derived saturation level of zonal current, which is shown to play a comparable role in saturating RSAE with the ZFZS scattering.

Results of Scanning Electron Microscopy of Explanted Hydrophilic Acrylic IOLs

Purpose: study the microscopic examination and microtopography of explanted hydrophilic acrylic IOLs with opacification.Material and methods. 5 samples of soft hydrophilic acrylic IOLs produced in European countries and the USA were studied. Explanted IOLs were studied using a scanning electron microscope (EVO LS10, Karl Zeiss, Germany-UK).Results. In 4 cases changes in hydrophilic acrylic IOL had the character of surface opacification in the area of the anterior wall of the optical element of the lens with localization in the Central zone (pupil area). In one case, the opacities were located over the entire surface of a hydrophilic IOL having a hydrophobic coating. The changes were characterized by the formation of crystalline deposits on the IOL surface at different stages of evolution. In the initial stage, primary point precipitates with sizes of 3–5 microns were formed. At a later stage, the changes had the form of “adult” spherocrystals with a typical radial-concentric zonal structure, up to 50 microns in size. In one of the of IOLs, the growth of crystals under the surface of the lens — in the thickness of IOLs was determined.Conclusion. The changes characterize different stages of the same type of pathological process with sedimentation of crystal deposits on the surface of IOL with changing crystallomorphology.

Experimental study of mobilistic mechanisms of formation of the Alpine folded structure of the Greater Caucasus

В статье рассмотрен вопрос о механизме образования складчатости Большого Кавказа, который до сих пор является дискуссионным. В настоящее время условия формирования главной (допозднеорогенной) структуры региона объясняются большинством исследователей мобилисткими поддвиговими и придвиговыми механизмами складкообразования, установленными анализом полевых материалов. Однако, для решения этого вопроса, необходимо провести экспериментальные ис- следования возможностей этих механизмов, чтобы убедиться в их достоверности. Цель работы. Экспериментальное исследование поддвиговых и придвиговых механизмов формирования складчатой структуры, для установления подобия, полученной с помощью моделирования складчатости и структуры Большого Кавказа. Методика исследований заключалась в проведении экспериментального моделирования процессов складкогенеза. Модели, имитирующие осадочные толщи Большого Кавказа, состояли из пачек чередования горизонтальных слоев петролатума, которые помещались между двумя деревянными бру- сками. При моделировании поддвигового механизма складчатости, давящий брусок имел клинообразную форму, чем имитировались сколовые пологие разломы. В опытах придвигового механизма деформации активный брусок имел крутую грань, чем воспроизводился субвертикальный наклон краевого разлома. Исходные модели помещались в специальный прибор, где они подвергались односторонней тангенциальной деформации. Результаты. При моделировании поддвигового механизма образования складчатости в процессе косого сжатия в слоистой толще наблюдались надвиговые (поддвиговые) смещения вдоль пологой поверхности сколового разлома почти недеформированных слоев. За ними в условиях горизонтального сжатия в слоистой пачке возникла субвертикальная мелкая сильносжатая складчатость. В процессе моделирования придвигового механизма складкогенеза бруски с крутыми гранями прижимались к слоевой пачке. Во время параллельной к слоистости деформации модели, вблизи давящего блока, возникла зональная субвертикальная тесносжатая складчатость. Ее напряженность уменьшалась в сторону пассивного бруска, где она переходила в моноклинальную структуру. В процессе моделирования в поддвиговых опытах образовалась зональная складчатость, интенсивность которой возрастала с удалением от места давления. Такая морфология складчатости не характерна региону, что противоречит гипотезе о поддвиговом механизме его складкообразования. В придвиговых экспериментах также образовалась асимметричная зональная структура, но ее напряженность уменьшалась в обратном направлении. Аналогичная зональность складчатой структуры развита в пределах Большого Кавказа, что подтверждает возможность ее формирования придвиговым механизмом тектогенеза. In the article is discussed the mechanism of folding of the Greater Caucasus, which is still controversial. At present, the conditions for the formation of the main (pre-late orogenic) structure of the region, by most researchers in the result of analysis of the field data are considered as mobile underthrusting and thrusting mechanisms of folding. However, to resolve this issue, it is necessary to conduct experimental studies of the capabilities of these mechanisms to ensure their reliability. Aim. Experimental study of the underthrusting and thrusting mechanisms of the formation of a folded structure, to establish the similarity of the folding obtained by modeling and structure of the Greater Caucasus. The research methodology consisted in carrying out experimental modeling of fold genesis processes. Models imitating sedimentary strata of the Greater Caucasus consisted of packs of alternating horizontal layers of petrolatum, which were placed between two wooden blocks. When modeling the underthrusting mechanism of folding, the pressing bar had a wedge shape, which simulated gently sloping shear faults. In experiments with the thrusting mechanism of deformation, the active bars had steep edges, which produced the subvertical inclination of the edge fault. The original models were placed in a special device, where they were subjected to one-sided tangential deformation. Results. During modeling the underthrusting mechanism of folding in the process of oblique compression in the layered strata, overthrust (underthrust) displacements were observed along the gently-dipping surface of the shear fault of the almost undeformed layers. Behind them, under horizontal compression in the layered pack, subvertical highly compressed small scaled folding has developed. In the process of modeling the thrusting mechanism of folding genesis, bars with steep edges were pressed against the layered stack. During the deformation of the model parallel to the bedding, a zonal subvertical tightly compressed folding appeared near the pressing block. Its strength decreased towards the passive bar, where it passed into a monoclinal structure. In the course of modeling in underthrusting experiments, zonal folding was formed, the intensity of which increased with distance from the place of pressure. This folding morphology is not typical for the region, which contradicts the hypothesis of the underthrusting mechanism of its folding. In thrust experiments, an asymmetric zonal structure was also formed, but its tension decreased in the opposite direction. A similar zoning of the folded structure is developed within the Greater Caucasus, which confirms the possibility of its formation by the thrust mechanism of tectogenesis

Mineralogical-geochemical features of corundum Miaskite-pegmatite from mine no. 210 (Ilmeny mountains, South Urals): preliminary results

Miaskite-pegmatite of mine no. 210 exhibits an unusual mineral composition for the Ilmeny Mountains. It contains a signifcant amount of sapphire-like corundum (uncommon of nepheline-bearing pegmatites) and various Th-bearing minerals («thoro-aeschinite», pyrochlore, phosphates). Pegmatite has a zonal structure, in which the central nepheline and lateral feldspar zones difer in composition of rock-forming and accessory minerals. Corundum is found in all zones of pegmatite. Accessory minerals of the central, eastern, and western zones include (i) Ti-niobates (columbite, pyrochlore, srilankite), zircon, spinel and thorianite, (ii) columbite, pyrochlore and zircon, and (iii) columbite, «ilmenorutile», toro-aeschinite, monazite-La and Ce, and zircon, respectively. The calculations based on two-feldspar thermometer for diferent pegmatite zones show a decrease in temperature from the periphery toward the center, which is in agreement with the variability of mineral assemblages. Pegmatite is strongly altered, which is expressed in the formation of cancrinite and sodalite, hydration of pyrochlore of the central zone, and signifcant compositional changes of Ti-niobates in the lateral zones of pegmatite. The Rb-Sr age of corundum miaskite-pegmatite is ~275 Ma, but the Rb-Sr system is signifcantly destroyed. The initial 87Sr/86Sr(275) isotopic ratio and ?Nd(275) value of the mineral indicate its crustal formation conditions. The geochemistry of corundum points to its multistage crystallization. The data points on Fe vs. Ga / Mg and FeO – Cr2O3 – MgO – V2O3 vs. FeO + TiO2 + Ga2O3 plots correspond to both «magmatic» and «metasomatic» corundum.

Some Peculiarities of Urolith Ontogeny of the Inhabitants of Dnipropetrovsk Region

According to the data of World Health Organization, the incidence of a disease of inhabitants with urolithiasis is constantly growing; moreover the number of recurrences of this disease is stable at 70%. The purpose of the work is to identify some features of the ontogenesis of uroliths from the kidneys of the inhabitants of Dnipropetrovsk region, primarily related to the structure and morphology of these formations. Based on comparative analyzes of morphological observations of more than 300 kidney stones investigated in inhabitants of Dnipropetrovsk region, it was found that spherulites and druse-like aggregates as well as their combinations are the most common among them. Moreover areas of attachment to renal papillae are usually observed on the surface of spherulitic formations and, as a rule, druse-like aggregates are formed in free space of a renal pelvis. Therefore, the specific features of the morphology of urinary stones allow to establish the most favorable areas of the urinary system for their predominant formation in each patient. Urolites of spherical shape differ in zonal structure, while the zonal structure is formed by the alternation of both essentially mineral and mainly organic layers, and mineral layers of different composition as well. Mineralogical and petrographic studies of urinary stones revealed the presence of 15 mineral species, mainly urate and oxalate compounds, with monomineral formations occurring in less than 1%. Multiscale microblocking and the presence of organic matter inclusions are characteristic features of the crystals of all established minerals. The central part of the uroliths is usually represented by accumulations of organic matter containing a highly dispersed mineral component. It is proved that such characteristics as color, size, shape and character of the surface of uroliths of the inhabitants of Dnipropetrovsk region are not very informative for the establishment of their predominant mineral composition. The accumulation of analytical material on the ontogenesis of urinary stones, their structure and mineral composition and its generalization, taking into account the medical and biological characteristics of each patient and the geoecological state of the region, could contribute to solution of an important social task — prevention and effective treatment of urolithiasis.