High-temperature electrical conductivity of clinopyroxenites in relation to their genesis (Kytlym ultramafic massif of the platinum belt of the Urals)

The electrical parameters (activation energy and electrical resistance coefficient) of rock samples were measured, and the character of their distribution was established. It was revealed that variations in electrical conductivity are related to the genetic features of clinopyroxenites, which allows us to suggest their relative age.     

Mineralogy and genesis of the Belogorsk skarn-magnetite deposit,primorye

The particularity of the formation of the skarn lodes of the Cretaceous-Paleogene Belogorsk deposit is the intense replacement of the early mineral assemblages (the decomposition of garnet, pyroxene, and pyroxenoids) with decreasing temperature, the increase in the amount of magnetite at the expense of Fe released from the decomposed minerals, and the formation of quartz and volatile-rich compounds (calcite, fluorite, amphibole, and sulfides). The geochemical and mineralogical similarity suggests a genetic relation between the manganese skarn lodes of the Belogorsk deposit (the Ol’ginsk ore district) and the stratabound bodies of the manganese silicate rocks (the Triassic contact metamorphosed metalliferous sediments) of the adjacent Shirokaya Pad area (as a source of matter).     

Chemical composition and genesis of the carbonic-acid mineral waters of the Tersinskoe deposit (Kuzbass)

This article presents the data of studies of ion-salt, microcomponent, gas, and isotopic compositions of water and the equilibrium calculation results for the water-rock system. The Tersinskie carbonic-acid waters are shown to be genetically close to soda waters of the Kuznetsk Basin (Kuzbass) in the zone with slowed water exchange. Taking these data into account, the concept of formation of carbonic-acid mineral waters not connected with magmatic or volcanic activities in the region was developed. According to this hypothesis, carbonic-acid waters are soda waters of regional occurrence, their composition being considerably changed due to CO₂ introduction from the deeper zones of the Earth’s crust along the zones of tectonic ruptures.     

Genesis of Levikha ores in relation to isotopic composition of their sulfur

Isotopic composition of sulfur was determined in more than 150 samples of sulfides and sulfates from the Levikha ore field. On the basis of the results so obtained, we are discussing the sources of sulfur in the sulfide ores and in sulfates of the ore deposits, physicochemical conditions of their deposition, and their genetic connections with sulfides in the overburden. -- Authors.     

Bismuth mineralization in ores of the Skrytoe scheelite deposit (Primorye) and problems of its genesis

The mineral composition of ore veinlets at the Skrytoe deposit (Malinovsky ore node, Primorye) is scrutinized based on the study of core samples from boreholes. It has been established that high Bi and Te concentrations in ores are related to the presence of native bismuth, Ag-Pb-Bi sulfosalts of the lillianite-gustavite series (gustavite, schirmerite, treasurite, and others), bismuth sulfides (bismuthinite and ikunolite), and bismuth sulfotellurides (joseite-A). The chemical compositions of bismuth minerals and their structural interrelations, as well as the attributes of their similarity with mineralization at other compositionally identical deposits in the region, are considered. Problems of the genesis and formational affiliation of the deposit are discussed.     

Patterns of ore localization and the mineral composition of ores and ore-bearing rocks of the Koretkonde uranium deposit (Vitim ore-bearing region)

This work presents the geological structure of the Neogen uranium-bearing ore sedimentary strata that filled the paleovalleys of the Koretkonde deposit. As a result of work we carried out, productive deposits were stratigraphically divided, the patterns of the localization of uranium mineralization were studied, and lithological and mineralogical ore-controlling factors were revealed. The main mineral phases of uranium were identified with scanning-electron microscopy and microprobe studies. In the future, a more detailed study of the deposits is planned in order to reveal methods for improving the efficiency of their exploration and organize the search for uranium deposits of such a type within the Vitim uranium-bearing ore region to expand the mineral resource base of Russia.     

云南羊拉铜矿矽卡岩形成时代与矿床成因：来自石榴子石和磁铁矿组分的约束

羊拉铜矿是金沙江缝合带中部已发现的规模最大的印支期铜矿床,矿体以层状—似层状产出于花岗闪长岩外围、变质砂岩与碳酸盐岩地层的层间破碎带中。该矿床在成因类型上存在喷流-沉积成因、复合成因、矽卡岩成因等多种观点。本文以矽卡岩矿石中石榴子石、磁铁矿为研究对象,利用LA-ICP-MS原位微区分析技术开展了石榴子石U-Pb年代学和石榴子石、磁铁矿成分测试分析,以进一步限定该矿床成矿时代和成因类型。分析结果显示,石榴子石中U、Th、Pb的含量分别为1.18×10^-6～6.69×10^-6、0.04×10^-6～1.43×10^-6、0.11×10^-6～1.16×10^-6,获得Tera-Wasserburg下交点年龄为231.0±5.3 Ma(2σ,n=32,MSWD=2.1),与矿区花岗闪长岩形成时代高度一致。结合磁铁矿微量元素组成与全球矽卡岩型矿床可类比等特征,明确羊拉铜矿床属于典型矽卡岩型铜矿床。石榴子石以钙铁榴石组分为主,具轻稀土富集、重稀土亏损的配分模式,这可能受晶体...     

Geochemical model for the genesis of Gongchangling rich magnetite deposit in China

Based upon geological and geochemical data on the genesis of Gongchangling rich magnetite deposit, it is suggested that the deposit is of multi-genesis, and a three-stage geochemical model for the genesis of the deposit is proposed:

1. Sedimentary stage: the deposition of BIF (magnetite-quartzite) was accompanied by high-grade magnetite (hematite)-siderite ores which are intercalated with magnetite-quartzites as lenses or stratoid shoots.
2. Metamorphic stage: in response to metamorphism, siderite, was decomposed into magnetite and graphite with decreasing f_{O 2} and increasingP _{CO 2}. In the marginal parts of magnetite-siderite ores or within the thin-layered interbeds where f_{O 2} was high relative toP _{CO 2} were formed graphite-free rich magnetite ores.
3. Hydrothermal stage: as a result of later hydrothermal process diffusive metasomatism between the rich ores and the host rocks and silica leaching took place, thus giving rise to the rich magnetite ore of metasomatic type and altered rocks.

     

新疆阿克陶县苏巴什一带磁铁矿地质特征及成因浅析

新疆阿克陶县苏巴什一带具有优越的成矿地质条件,带内相继发现了多个铁矿床,并具有一定的空间连续性。本文通过总结对比带内不同铁矿床的地质特征、赋矿地层、构造变质变形等特征,并以带内典型的磁铁矿床为例,深入分析矿体地质特征、矿体形态、矿物组合及矿石结构构造特征,认为该地区的磁铁矿具有相似的矿床成因及成矿演化史,经历了原始沉积期、区域变质改造期和热液叠加改造期3个阶段,属于沉积变质型磁铁矿。通过物探磁测,明确了区内磁异常主要由磁铁矿（化）引起,并总结了带内磁铁矿找矿标志,为该区铁矿进一步勘探调查指明方向。     

西藏措勤县木质顶磁铁矿矿床地质特征及成因分析

本文介绍了尼雄木质顶磁铁矿床地质特征.从成矿的控矿因素,矿质来源,及矿物的晶体结构,光学性质等方面对矿床的成因作了分析,得出该矿床为接触交代矿床结论,对矿区地质勘查及外围找矿具有一定的指导意义.     

辽宁高家堡子银矿床矿石晶洞构造及其成因机制

高家堡子银矿床是在辽东青城子铅锌矿田内发现的一大型独立银矿床,赋存于辽河群大石桥组第三段以大理岩为主的地层之中,矿体形态及产状受层间破碎带构造控制。矿区矿石分为硅化石英脉型及碎裂大理岩型两类,其中前者为矿区主要的富银矿石。该类矿石晶洞构造极其发育,根据地质及流体包裹体研究成果,认为矿石中的晶洞构造是岩浆来源富CO2流体溶蚀赋矿的大理岩围岩形成的溶洞,被晚期以大气降水为主流体充填形成晶簇状石英。     

Material composition and geochemical characteristics of ores of the Malinovskoe gold-ore deposit (Primorskii Krai,Russia)

The mineral composition and geochemical characteristics of the ores of the Malinovskoe gold-ore deposit are studied by the data from mining works (ditches, cleanings, and boreholes). It is found that the ore–magma system of the deposit was formed in several stages of mineralization characterized by two phases of magmatism differing in age. In terms of the set of features (the geological–structural position of the deposit, as well as the material composition and geochemical characteristics of the ores), the deposit is attributed to the gold–tourmaline type of mineralization associated spatially and genetically with the “raremetal” granitoid magmatism. This type has not previously been found in Primorskii Krai. The studies of the material composition and geochemical characteristics of the ores allow us to ascertain the correlations between the elements along with the reasons of their origination. By analogy with other gold-ore formations of the Russian Far East, the mineralogical and geochemical model of the deposit is developed (Be–Sn–Cr–Ba–Au–Cu–Mo–Pb–V–Ti–Co–W–Ag–Bi–Ni–Mn–Sr–Zn–Sb–As modeling element series of vertical zoning), which enables us to estimate the levels of the erosion section of the ore bodies and to evaluate their prospects. It is found that the most productive associations in the deposit are the gold–bismuth geochemical association (Au–Ag–Bi–Cu–As–Co) and, to a lesser degree, the gold–tungsten association (W–Au–Ag–Cu–Bi–As).     

新疆南天山查岗诺尔大型磁铁矿矿床地质特征及矿床成因

查岗诺尔铁矿床为新疆南天山近年来发现的大型磁铁矿床.该矿床产于南天山造山带下石炭统大哈拉军山组火山-碎屑-碳酸岩建造中,储量达到1.3亿吨.矿床由多个平行于地层层理的矿体组成,其主矿体位于隐爆角砾岩内.主要的矿物组合包括磁铁矿、磁赤铁矿、穆磁铁矿、赤铁矿、假象赤铁矿及极少量的镜铁矿等.通过对矿石的结构、构造以及矿石矿物化学成分的综合分析,表明该矿床的形成与火山通道附近的潜火山构造隐爆作用密切相关.该矿床的发现为区域上寻找同类矿床提供了广阔的找矿前景.     

Authigenous mineral parageneses in sedimentary ores and their critical factors

ABSTRACT: The authigenous mineral parageneses in oölitic hydrogoethite-chamosite-siderite ores, manganese ores, and sedimentary concentrations of Cu, Pb and Zn are compared, and the reasons for their differences clarified. -- Author.     

Characteristics of selenium and tellurium distribution in mineral associations of ores of the Priorsk deposit

Pyrite, pyrrhotite, chalcopyrite, and sphalerite are the principal carriers of tellurium, in an ore body which lies at the contact of hydrothennally altered rocks (albite-sericite-quartz and chlorite-quartz) with their host diabases and spilites. Selenium, variable as it is, shows a definite preference of chalcopyrite-pyritic and chalcopyrite-pyrite-pyrrhotite associations. Selenium increases consistently from the hanging wall to the footwall of the ore body, except in the magnetitic association, where it is inordinately low. The Priorskoye ores are somewhat higher in selenium and are much poorer in tellurium than the other pyritic ore in Southern and Middle Ural. — V.P. Sokoloff     

Isotopic composition of sulfur and genesis of copper ores of Zdhezkazgan and Udokan

Enrichment of S³² in sulfidic sulfur and large variations in δS³⁴ content of certain minerals are characteristic of the ores. It is possible therefore that their sulfur was derived from sedimentary rocks and that bacterial reduction of sedimentary sulfates had a part in the process. The isotopic composition of sulfidic sulfur in cupriferous sandstones and in the veinlets therein is about the same. Consequently, a borrowing a sulfur by the veinlets from the sandstones appears to be a reasonable assumption. A biogenic-sedimentary origin of the sulfides does not preclude accessions of copper and other metals from the magma. -- Author.     

刚果(布)布谷马西钾盐矿床盐类矿物特征与成因研究

刚果(布)布谷马西钾盐矿床位于非洲大陆西部边缘,是白垩纪时期沉积的大型钾盐矿床。文章运用X射线衍射、薄片鉴定、扫描电镜和岩石地球化学等方法,识别出布谷马西钾盐矿的主要盐类矿物有硬石膏、石盐、光卤石、钾石盐、水氯镁石和溢晶石。盐类矿物的沉积顺序为:硬石膏→石盐→光卤石→钾石盐→水氯镁石或溢晶石。该矿区的成盐物质主要来源于海水,盐类沉积物中贫碳酸盐和硫酸盐矿物,可能与白垩纪"方解石海"的海水成分密切相关。矿区中的钾石盐主要是由光卤石淋滤形成。     

Mineralogical and geochemical zoning and genesis of massive sulfide ores at the Oktyabr’sky deposit

Fractional crystallization and emanation differentiation of sulfide magma and related mineralogical and geochemical zoning are exemplified in massive sulfide ores of the Oktyabr’sky deposit, Noril’sk district. The mineralogical zoning is expressed in the change of mineral types of ore from pyrrhotite (Po) to chalcopyrite (Cp) (from the flanks to the center of the ore lode). In terms of geochemistry, the Cu content, Cu/(Cu + Ni) ratio, and contents of noble metals incompatible with Mss (Pt, Pd, and Au) increase in this direction, while the S and Fe contents decrease. The distribution of elements compatible with Mss (Ir, Os, Rh, and Ru) is more complex. Their contents decrease from Po to high-Cu Cp ore, although there is a second maximum for Cb-type ore. The distribution of ore elements in the vertical and horizontal sections of massive ores at the deposit is different. The upper outer contact zone and frontal parts of massive ore lodes are enriched in all ore elements and a light sulfur isotope. The succession of enrichment is correlated with the relative affinity for sulfur and remains independent of the affinity of these elements for Mss (Pd-Rh, Os-Au). The possible role of liquid immiscibility of sulfide magma in the development of the mineralogical and geochemical zoning of massive ore is discussed.