Alunite-containing mineral associations of the Nikopol manganese deposit’s ore stratum and their genetic significance

2015 ◽  
Vol 1 (1) ◽  
pp. 43
Author(s):  
M.L. Kutsevol ◽  
L.I. Kutsevol
2018 ◽  
Vol 79 (1) ◽  
pp. 47-69 ◽  
Author(s):  
Jovica Stojanovic ◽  
Slobodan Radosavljevic ◽  
Radule Tosovic ◽  
Aleksandar Pacevski ◽  
Ana Radosavljevic-Mihajlovic ◽  
...  

The Rudnik orefield is one of the well-known skarn-replacement and high-temperature hydrothermal Pb-Zn-Cu-Ag-Bi-W polymetallic sulfide deposits, and is a part of the Sumadija Metallogenic District, Serbia. It comprises ore bodies grouped into several major ore zones. The pseudostratified and platelike ore bodies have relatively high content of valuable metals. The average content varies in wide ranges: Pb (0.94-5.66 wt%), Zn (0.49-4.49 wt%), Cu (0.08-2.18 wt%), Ag (50-297 ppm), Bi (~100-150 ppm), and Cd (~100-150 ppm). Generally, a complex mineral association has been determined. Iron sulfides, arsenopyrite, chalcopyrite, sphalerite, galena and sulfosalts are abundant minerals in the ore. Carrier minerals of Bi and Ag are Bi-sulfosalts, such as galenobismutite, cosalite, Ag-bearing aschamalmite, vikingite, schirmerite and gustavite. Copper, Ag and Pb-Sb sulfosalts have been found only locally. Complex Ni-minerals (sulfides, arsenides and sulfoarsenid?s) with Fe, Co and Ag were formed under to the influence of present serpentine rocks and their yield of Ni, Co and Cr in the hydrothermal ore-bearing solutions. Significant scheelite mineralizations have been found in the Nova Jama, Gusavi Potok and Azna ore zones. The presence of Bi-sulfosalts and argentopentlandite suggests formation temperatures higher than 350, and lower than 445?C, respectively. Therefore, the mineralization was formed in the temperature range 350 to 400?C. The continuity of pyrite, pyrrhotite and siderite colloform bands in relic aggregates shows frequent changes of fS2 and fO2 in hydrothermal solutions. Isotopic composition of sulfur also confirms that the source of the ore-bearing fluids was magmatic. In addition, the enrichment of Bi and Ag indicates a magmatic origin. The appearance of Biminerals represents a significant genetic indicator for detection of increased Ag concentrations within the ore mineralizations. Typical gangue minerals are quartz, silicates, carbonates, oxides and different oxy-hydroxides. Special attention is given to the paragenetic relationships and the genetic significance of mineral associations as indicators of ore-forming conditions.


Genetics ◽  
1992 ◽  
Vol 131 (2) ◽  
pp. 461-469 ◽  
Author(s):  
F W Schnell ◽  
C C Cockerham

Abstract In this article we investigate multiplicative effects between genes in relation to heterosis. The extensive literature on heterosis due to multiplicative effects between characters is reviewed, as is earlier work on the genetic description of heterosis. A two-locus diallelic model of arbitrary gene action is used to derive linear parameters for two multiplicative models. With multiplicative action between loci, epistatic effects are nonlinear functions of one-locus effects and the mean. With completely multiplicative action, the mean and additive effects form similar restrictions for all the rest of the effects. Extensions to more than two loci are indicated. The linear parameters of various models are then used to describe heterosis, which is taken as the difference between respective averages of a cross (F1) and its two parent populations (P). The difference (F2 - P) is also discussed. Two parts of heterosis are distinguished: part I arising from dominance, and part II due to additive x additive (a x a)-epistasis. Heterosis with multiplicative action between loci implies multiplicative accumulation of heterosis present at individual loci in part I, in addition to multiplicative (a x a)-interaction in part II. Heterosis with completely multiplicative action can only be negative (i.e., the F1 values must be less than the midparent), but the difference (F2 - P) can be positive under certain conditions. Heterosis without dominance can arise from multiplicative as well as any other nonadditive action between loci, as is exemplified by diminishing return interaction. The discussion enlarges the scope in various directions: the genetic significance of multiplicative models is considered.(ABSTRACT TRUNCATED AT 250 WORDS)


2009 ◽  
Vol 424 (1) ◽  
pp. 68-71
Author(s):  
O. V. Avchenko
Keyword(s):  

2007 ◽  
Vol 21 (2) ◽  
pp. 461-467 ◽  
Author(s):  
Yinghui Liu ◽  
Rajendar Gupta ◽  
Terry Wall

Nutrients ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 1123
Author(s):  
Carole Ayoub Moubareck

Human milk represents a cornerstone for growth and development of infants, with extensive array of benefits. In addition to exceptionally nutritive and bioactive components, human milk encompasses a complex community of signature bacteria that helps establish infant gut microbiota, contributes to maturation of infant immune system, and competitively interferes with pathogens. Among bioactive constituents of milk, human milk oligosaccharides (HMOs) are particularly significant. These are non-digestible carbohydrates forming the third largest solid component in human milk. Valuable effects of HMOs include shaping intestinal microbiota, imparting antimicrobial effects, developing intestinal barrier, and modulating immune response. Moreover, recent investigations suggest correlations between HMOs and milk microbiota, with complex links possibly existing with environmental factors, genetics, geographical location, and other factors. In this review, and from a physiological and health implications perspective, milk benefits for newborns and mothers are highlighted. From a microbiological perspective, a focused insight into milk microbiota, including origins, diversity, benefits, and effect of maternal diet is presented. From a metabolic perspective, biochemical, physiological, and genetic significance of HMOs, and their probable relations to milk microbiota, are addressed. Ongoing research into mechanistic processes through which the rich biological assets of milk promote development, shaping of microbiota, and immunity is tackled.


Author(s):  
Vasif Mamad Aga oglu Baba-zadeh ◽  
Narmina Nazim kyzy Ismayilova ◽  
Nazim Ajdar oglu Imamverdiyev ◽  
Shakhla Faig kyzy Abdullaeva

The article discusses the geochemical features of the Tulallar gold field in the Lesser Caucasus. Distributions of gold and accompanying elements (Ag, As, Hg, Bi, Cu, Zn) in metasomatically altered rocks taken from mine workings (ditches, adits, etc.) and wells are considered. The results of analyzes of furrow samples showed that the content of Au ranges from 0.4 ppm to 37.5 ppm, Ag - from 0.5 ppm to 48.4 ppm. In strongly kaolinized, weakly limonitized quartzites, the Au content ranged from 0.4 to 1.2 ppm, Ag - from 4.0 to 8.8 ppm. In the well drilled in the Central Block, closer to the surface, the siliceous breccias contain Au 309-363 ppm, Ag 132-250 ppm, and high As, Bi and Hg contents are also noted. A similar picture is observed in the silicified rocks of the wells of the Western block. Correlations between Au, Ag and other impurity elements were determined using the STAT program. A direct positive correlation has been established between Au and Ag, Au and Bi, Au and Hg. A positive relationship was also found between Ag and Bi, Ag and Hg. Cluster analysis revealed two different mineral associations: 1) native elements and their compounds - minerals and 2) polysulfide. The closest connection is observed between Ag, Hg and Au. Mineralogically, the Ag-Hg-Au-Bi cluster apparently corresponds to an early ore association - electrum, bismuth tellurides, possibly with inclusions of finely dispersed gold. The second, polymetallic cluster is characterized by a weak correlation bond Аs-Сu-Zn, which indicates that polysulfides were deposited later. The largest amount of Au was deposited in the early mineral association.


2020 ◽  

The book is devoted to the International Baikal Drilling Project, a part of the program «Global changes of the environment and climate», accomplished by the Russian, American and Japanese scientists. Much attention is given to the fact that the Baikal Drilling team acted as a single, solid team. The major results obtained from those studies were described in numerous publications published in various Russian and International journals. We hope that the book will be interesting for young scientists, so that they can feel an interest in studying the secrets of nature. The project was accomplished owing to the efforts of M.I. Kuzmin, V.S. Antipin, A.V. Goreglyad, V.F. Geletyi, G.V. Kalmychkov (Institute of Geochemistry, SB RAS), M.A Grachev, O.M. Khlystov (Limnological Institute, SB RAS). Many problems that arouse in the project management were solved with the assistance of V.A. Fialkov, Director of the Baikal Museum, SB RAS, A.A. Bukharov, Vive-Director of the Baikal Museum, and the translators T. V. Bunaeva and M. Yu. Khomutova. The book not only describes a difficult work in the ice of Lake Baikal, but also presents the valuable data on the mineral composition of the bottom sediments, the discovery of Baikal gas hydrates, and the evolution of the landscapes and climate of the Baikal region in the Late Cenozoic. Modern methods of electron-probe x-ray spectral microanalysis and isotope geochemistry are described in detail. All this, as well as the methods of modeling real mineral associations, make this book valuable for researchers in different fields of science.


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