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Date submitted2020-05-28
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Date accepted2020-05-28
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Date published2020-06-30
The age of mineralization of Mayskoe gold ore deposit (Central Chukotka): results of Re-Os isotopic dating
The article presents the results of the sulfide mineralization dating of the Mayskoe gold ore deposit using the Re-Os isotope system and isochron age estimation method of the main sulfide minerals: arsenopyrite, pyrite, and antimonite. The complex multistage formation of the studied sulfides, as well as the close intergrowths of genetically different mineral phases, did not allow obtaining a single rhenium-osmium isochron corresponding to the formation time of sulfide mineralization. Isochrones for single minerals, collected from each sulfide sample, turned out to be the result of isotopically distinct components mixture (radiogenic crustal and non-radiogenic mantle) and do not make sense from the geochronological point of view. In terms of geology, the most significant result of the study is an age estimation of 128.8 ± 4.4 Ma, obtained for the sulfide mineralization of Mayskoe deposit using Re-Os isotope dating of single fractions of pyrite and antimonite of the ore mineralization stage. While arsenopyrite is most closely associated with gold mineralization, one of the arsenopyrite varieties corrodes framboidal pyrite of the pre-ore stage, has a maximum of the crust component in the osmium isotopic composition and forms a mixing line in the isochron diagram with an apparent formation age of 458 ± 18 Ma. The initial osmium isotopic composition of the studied sulfides indicates a mixed mantle-crust source of sulfide mineralization. The issue of simultaneous ore genesis and granitoid magmatism in the Mayskoe deposit remained unresolved (the age of granitoids according to the U-Pb zircon system is 108 Ma). However, a possible solution could be the further determination of the Re-Os isochron age of the ore mineralization sulphides from the single paragenesis of a specific sample containing both arsenopyrite and pyrite (+ antimonite) with gold.
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Date submitted2016-08-28
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Date accepted2016-11-04
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Date published2017-02-22
Deposits of gold-quartz formation in the Priamur province
- Authors:
- V. A. Stepanov
- A. V. Melnikov
A description of gold-quartz formation deposits in the Priamur gold province is presented. Prevalence of gold-quartz deposits defines metallogenic profile of the province and presence of numerous rich placers. Deposits are attributed to frontal, middle and near-bottom parts of the ore pipe. Frontal part of the ore pipe contains a major part of the deposits. They are small and consist of scattered quartz, feldspar-quartz and carbonate-quartz veins. The ore is characterized by erratic percentage of gold, bonanzas can be found. Gold is free, ranging from fine to big grains and small nuggets. It is associated with arsenopyrite, galenite, sometimes with antimonite. Among trace elements can be copper, mercury, antimony and arsenic. Prevalence of frontal deposits in the province points to significant prospects of finding a rich deep mineralization in the middle part of ore pipe. Middle part of the ore pipe contains intermediate and small deposits. Ore bodies are often represented by veined and veinlet-disseminated zones, sometimes zones of metasomatites. For gold-quartz ores, free native gold can commonly be found, usually of fine and very fine grain size. Among ore minerals, apart from arsenopyrite, pyrite and galenite, scheelite is frequently observed.
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Date submitted2015-08-13
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Date accepted2015-10-29
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Date published2016-04-22
Multicriteria estimation of bearing capacity of geomaterials
- Authors:
- I. A. Brigadnov
In the article the problem of an estimation of bearing capacity of geomaterials as a deform-able solid is considered in the current configuration, which may be as the reference (undeformed) or the actual (deformed). We propose an original variational approach to the problem for stresses in selected subdomains, in which, depending on different engineering considerations, average in-tegral values of different component of stresses are estimated and from their aggregate the bearing capacity of the current configuration of the solid is estimated regarding to given external influ-ences. In each of the selected subdomain the weakest stress field is obtained which is globally bal-anced with external influences. For example, the assessment of the average integral hydrostatic pressure is needed for study of bearing capacity of geomaterials.
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Date submitted2009-10-23
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Date accepted2009-12-10
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Date published2010-09-22
Geomechanical substantiation of projects of ore deposits mining
- Authors:
- V. V. Zubkov
- A. A. Filinkov
The paper presents the monitoring system for better geodynamic safety in mining of mineral deposits. The suggested system of geodynamic monitoring allows us to evaluate the stress state of ore massif for the planned variant of mining and to give recommendations on the safe deposit mining. Based on the analysis of the modeling data, consideration was given to one of the variants of geomechanical substantiation of the project of ore deposit mining.
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Date submitted2009-08-22
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Date accepted2009-10-19
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Date published2010-02-01
The substantiation of reinforcing support of preparation mines in the ore massive of the Yakovlevskiy deposit
- Authors:
- Yu. N. Antonov
- V. Yu. Sinegubov
The paper justifies a design of reinforcing mine support of the protective roof at the priority high-grade ore mining site of the Yakovlevskiy deposit. Experience of mine roadway support with the KMP-A3 standing support has been analyzed. A reinforcing support is offered consisting of rock bolts back bracing the ore exposure, which best fits with continuous miner roadheading and consolidating stowing (concrete).
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Date submitted2008-11-13
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Date accepted2009-01-01
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Date published2009-12-11
The quality of commodity output – the factor of competitiveness iron-ore branch
- Authors:
- R. V. Korchenkov
The problems of quality improving of commodity output are the most urgent and up-to date questions in the period of intromission of Russian on the world market. The country possesses of significant mineral raw ferrous materials, which are poor quality. In conjunction with it mining-and-processing integrated works must develop and improve the process of production in order to provide the quality of the products conforming to world requirements. The main task of iron-ore branch in Russia is to maintain the competitive ability on the foreign market.
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Date submitted2008-10-14
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Date accepted2008-12-21
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Date published2009-12-11
Results of profile magnetotelluric researches at the Ozernoye ore cluster in Buryatiya Republic
Primary results of MT profiles surveys interpretation are presented. The investigations have been carried out in 2007. Ozernoye pyrite-polymetallic deposit is of special interest. Magnetotelluric and audiomagnetotelluric investigations have been carried along one profile, crossing all over the territory of Ozernoye ore cluster, and along some more detailed profiles inside already discovered deposits. As a result of the investigations some new data on relict structure, which is the host of Ozernoye pyrite-polymetallic deposit, are obtaned.