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枪口南银多金属矿床地处东昆仑多金属成矿带东段,枪口—哈龙休玛海西-燕山期铁、银、铅、锌、铜、金、钼成矿亚带部分,成矿地质条件优越。枪口南银多金属矿区目前已圈定9条矿化带,21个矿体,主要矿种有金、银、铜、铅、锌、钼等,矿石类型主要为构造热液(脉)型铜铅锌银矿石、构造蚀变岩型金矿石。枪口南矿区构造-岩浆活动强烈,印支期—燕山期构造岩浆活动为矿区成矿提供了热源、成矿物质,区内NE向断裂控制区内金、铜、铅锌等矿体的产出,NW向断裂组控制着区内金、银矿(化)体。NW向断裂组,是区内重要控矿构造;区内中部发现的Ⅳ号含矿斑岩体,具有斑岩型矿床蚀变特征,显示其具有斑岩成矿条件。枪口南银多金属矿床成因有构造热液(脉)型、构造蚀变岩型和斑岩型。 相似文献
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《International Geology Review》2012,54(9):1031-1051
The geotectonic units of Zhejiang Province include the Yangtze Plate in the northwest juxtaposed against the South China fold system in the southeast along the Jiangshan–Shaoxing fault. The South China fold system is further divided into the Chencai–Suichang uplift belt and the Wenzhou–Linhai geotectogene belt, whose boundary is the Yuyao–Lishui fault. The corresponding metallogenic belts are the Mo–Au(–Pb–Zn–Cu) metallogenic belt in northwest Zhejiang, the Chencai–Suichang Au–Ag–Pb–Zn–Mo metallogenic belt, and the coastal Ag–Pb–Zn–Mo–Au metallogenic belt. The main Mesozoic metal ore deposits include epithermal Au–Ag(Ag), hydrothermal vein-type Ag–Pb–Zn(Cu), and porphyry–skarn-type Mo and vein-type Mo deposits. These ore bodies are related to the Mesozoic volcanic-intrusive structure: the epithermal Au–Ag(Ag) deposits are represented by the Zhilingtou Au–Ag deposit and Houan Ag deposit and their veins are controlled by volcanic structure; the hydrothermal vein-type Ag–Pb–Zn deposits are represented by the Dalingkou Ag–Pb–Zn deposit and also controlled by volcanic structure; and the porphyry–skarn-type Mo deposits are represented by the Tongcun Mo deposit and the vein-type Mo deposits are represented by the Shipingchuan Mo deposit, all of which are related to granite porphyries. These metal ore deposits have close spatio-temporal relationships with each other; both the epithermal Au–Ag(Ag) deposits and the hydrothermal vein-type Ag–Pb–Zn deposits exhibit vertical zonations of the metallic elements and form a Mo–Pb–Zn–Au–Ag metallogenetic system. These Jurassic–Cretaceous deposits may be products of tectonic-volcanic-intrusive magmatic activities during the westward subduction of the Pacific Plate. Favourable metallogenetic conditions and breakthroughs in the recent prospecting show that there is great resource potential for porphyry-type deposits (Mo, Cu) in Zhejiang Province. 相似文献
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大兴安岭北部主要金属矿床成矿系列和区域矿床成矿谱系 总被引：10，自引：4，他引：6
文章以大兴安岭北部内生金属矿床、海相火山岩型硫铁矿矿床和砂金矿床为研究对象,按照矿床成矿系列的学术思想将其划分为7个矿床成矿系列,即:多宝山地区与加里东期中酸性火山_侵入活动有关的铜、钼矿床成矿系列,呼玛地区与华力西期辉长岩和花岗岩有关的铁、钛、金矿床成矿系列,伊尔施_黑河地区与华力西期花岗岩和海相火山岩有关的铁、铜、锌、硫铁矿矿床成矿系列,牙克石地区与华力西期海相中基性火山岩有关的铁、锌、硫铁矿矿床成矿系列,得尔布干地区与印支期_燕山期中酸性火山_侵入活动有关的铅、锌、银、铜、钼、金矿床成矿系列,伊尔施_呼玛地区与燕山期中酸性火山_侵入活动有关的金、铁、锌、铜、钼、钨矿床成矿系列和黑龙江流域与第四纪冲积沉积作用有关的砂金矿床成矿系列。大兴安岭北部区域矿床成矿谱系表明,从奥陶纪到新生代该区不同构造单元经历了7个主要的构造演化及成矿时期,依次出现奥陶纪岛弧环境的斑岩型矿床、泥盆纪陆块边缘拉张环境的岩浆型和热液脉型矿床、泥盆纪—石炭纪俯冲_碰撞环境的海相火山岩型和矽卡岩型矿床、石炭纪弧后盆地环境的海相火山岩型矿床、晚三叠世—早白垩世俯冲_碰撞_后碰撞环境的斑岩型、热液脉型、浅成低温热液型和矽卡岩型矿床、早侏罗世—早白垩世俯冲环境的斑岩型、热液脉型、浅成低温热液型和矽卡岩型矿床和新生代地壳差异运动带砂金矿床。大兴安岭北部优势矿种为铜、钼、金、银、铅、锌,主攻矿床类型为斑岩型、热液脉型、低硫化浅成低温热液型、冲积型和海相火山岩型。 相似文献
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B. De Vivo L.G. Closs A. Lima R. Marmolino V. Perrone 《Journal of Geochemical Exploration》1984,21(1-3)
A governmental regional drainage survey assessed the mineral potential of Calabria in 1974. The Calabria area of southern Italy is a mineralized region in which Penninic and Austro-Alpine nappes, comprising ophiolites, metasedimentary rocks (phyllites, paragneiss, granulites, amphibolites) and granitic and granodiorite plutons, are overthrusting carbonate Apenninic nappes. Pre-Alpine stratabound and vein-type base-metal sulfide mineralization predominate, tectonically redistributed during the Alpine orogeny.A total of 5518 samples of the original 6999 active stream sediments from an area of 10,000 km2 were analyzed by X-ray fluorescence and atomic absorption for Cu, Pb, Zn, Hg, Fe, Mn, As, W, Mo, Sn, and Be on the minus 180 μm fraction. Follow-up investigation of a 39-km2 area around Bivongi-Ferdinandea using 760 soil samples analyzed for Fe, Mn, Zn, Cu, Pb, K, Mo, and Au, investigated molybdenite and chalcopyrite occurrences associated with granodiorite.A five-factor R-mode factor analysis reflected geological and mineralization features in the reconnaissance data. Factor 1 (Fe-Mn-Cu-Zn) is related to the Fe and Mn distribution in the stream sediments. Factor 2 (Be-Sn) reflects presence of pegmatites within metamorphic and magmatic rocks. Factor 5 (Mo) is essentially a single-element factor. Factor 4 (As-Pb-Zn-Hg-Cu) reflects mineralization. Factor 3 (W-Ba) does not cluster in association with any specific lithological unit. Significant metal associations, recognized from R-mode factor analysis, were used as independent variables and regressed against the original metal concentration of each sample. Residuals of multiple regression analysis, differentiated features representing mineralization from those related either to lithologic or geochemical parameters. New prospecting targets were identified and areas of known mineral occurrences were evident in the distinction of residuals.R-mode factor analysis of data from the follow-up investigation identified three factors. Factor 2 (Mo-K) reflects Mo mineralization and associated hydrothermally altered areas but does not suggest additional target areas. 相似文献
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豫西银家沟硫铁多金属矿床是与中酸性斑岩小侵入体具成因联系的大型热液交代型矿床;矿床赋矿地层主要为蓟县系龙家园组和巡检司组含燧石条带白云岩;矿床的成矿岩体呈复式微型岩株,中心相为钾长花岗斑岩,边缘相为石英闪长斑岩,岩体为超浅成侵入伴随隐爆作用的次火山相岩浆岩;矿床以硫铁矿为主体,共/伴生有铁、铜、钼、铅、锌、银、金等;矿体以透镜状为主,均为隐伏矿体;成矿分为磁铁矿-赤铁矿阶段、石英-辉钼矿阶段、石英-中粗粒黄铁矿阶段、黄铜矿-磁黄铁矿阶段;铅锌硫化物为最晚期产物。银家沟硫铁多金属矿床具有成矿物质多来源、成矿多阶段的特点。成矿岩体自身携带大量成矿元素,同时萃取了围岩中的多种成矿元素,在环境适合的条件下沉淀成矿。 相似文献
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Afshin Akbarpour Nejat Gholami Hossin Azizi Farhad Mohhamad Torab 《Arabian Journal of Geosciences》2013,6(9):3397-3408
Masjed-Daghi is located in Julfa sheet (1:100,000 series) in the northwest of Iran. The area consists of a very likely gold mineralization bearing epithermal mineralization which appears to be associated with a porphyry Cu–Mo system at deeper levels. Ninety-three soil samples were collected and analyzed for 13 elements (Au, Mo, Cu, Pb, Sn, Ag, Zn, Cr, Mn, Ba, Be, Ni, Co) by using emission spectrometry and atomic absorption spectrophotometry. The data were processed and interpreted using univariate and multivariate statistical analyses. The distribution of the majority of variables is slightly to moderately positively skewed which can be interpreted by log-normal model. Only Ni, Be, and Mn show normal distribution. Based on cluster analysis, the variables can be classified into two main groups. The first group consists of the main ore forming elements such as Au, Ag, and Ba which belong to epithermal system and Mo, Sn, and Cu which have more affiliation to porphyry mineralization. The principal component analysis extracted three factors. These factors calculated using varimax rotated R-mode factor loading matrix account for more than 65 % of the total variance. The first factor represents the main constituents of the epithermal system (Au, Ag, Ba) and its geochemical halo at the northeast of the study area. The second factor represents the main constituents of the porphyry system (Cu, Mo, Sn) and its geochemical halo in the western part of the study area which is overlapped with the volcanic rocks affected by local intrusions with higher alteration overprint. The third factor, however with less significance, represents Pb and Zn which are not the main ore constituents but can be considered as pathfinder elements. The results have been used to locate hidden orebodies using presented factor score mapping. 相似文献
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东昆仑祁漫塔格成矿带矿床类型、时空分布及多金属成矿作用 总被引：22，自引：0，他引：22
基于笔者近几年对东昆仑祁漫塔格地区的野外调查和室内岩矿测试分析研究,综合论述了祁漫塔格成矿带的成矿地质背景、多金属矿床的主要类型、基本特征、时空分布和成矿作用特点。该区金属成矿元素组合复杂,矿床类型多样,矿种以F e、Cu、Pb、Zn、M o、W、Sn、A u为主,矿床类型主要有矽卡岩型、斑岩型、沉积-改造型和高温热液型等。探讨了祁漫塔格地区多金属矿床的成岩成矿时代、成矿物质和成矿流体来源,以及成矿地球动力学背景。提出中—晚三叠世和早古生代晚期是本区重要的成矿时期;形成于中—晚三叠世的斑岩型和矽卡岩型矿床金属成矿物质主要来源于岩浆和含碳酸盐岩地层,成矿流体主要来源于岩浆水,两者系同一构造岩浆活动在不同阶段、不同深度和不同部位发生成矿作用的产物。 相似文献
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矿床具斑岩型铜矿化蚀变特征,从岩体中心向外,蚀变呈环带状分带发育,依次为强硅化带→钾硅化带→绢英岩化带→青磐岩化带。矿化在浅部表现为断裂破碎带控制的热液脉型Cu、Au、Pb、Ag矿床,深部则为斑岩型Cu、Mo矿床。 相似文献
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滇西北香格里拉东炉房铜钼矿床斑岩-热液成矿特征及找矿预测 总被引：1，自引：0，他引：1
东炉房铜钼矿床位于扬子西缘坳陷带,是滇西北香格里拉地区近年新勘查评价的中型矿床,该矿床具大型规模远景。本次通过地质详查及综合研究工作,基本查明了矿床特征,理清了成矿规律,提出了深部及外围找矿预测区。研究认为:铜钼铅锌金多金属矿化与石英闪长玢岩-石英二长斑岩复式侵入岩紧密相关,矿化蚀变具有斑岩型-矽卡岩型-中低温热液脉型成矿系统特征;矿区共圈定24条矿体,其中斑岩型钼(铜)矿体3条,矽卡岩型铜(钼)矿体14条,中低温热液脉型铅锌(金)矿体7条,具有由内到外,由高温至中低温为Mo(Cu)→Cu(Mo)、Fe→Pb、Zn、Au的斑岩成矿系统元素分带特征;结合矿区矿床地质、地球物理、土壤地球化学特征,矿区外围及深部圈定3处寻找斑岩型-矽卡岩型铜钼多金属矿找矿靶区。该矿床的评价对区内寻找同类型矿床具有重要指示意义。 相似文献
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Selective chemical extraction of heavy metals in tailings and soils contaminated by mining activity: Environmental implications 总被引：1，自引：0，他引：1
Paulo J.C. Favas João Pratas M. Elisa P. Gomes V. Cala 《Journal of Geochemical Exploration》2011,111(3):160-171
Total concentrations of chemical elements in soils may not be enough to understand the mobility and bioavailability of the elements. It is important to characterise the degree of association of chemical elements in different physical and chemical phases of soil. Another geochemical characterisation methodology is to apply sequential selective chemical extraction techniques. A seven-step sequential extraction procedure was used to investigate the mobility and retention behaviour of Al, Fe, Mn, Cu, Zn, Pb, Cr, Co, Ni, Mo, Cd, Bi, Sn, W, Ag, As and U in specific physical–chemical and mineral phases in mine tailings and soils in the surroundings of the abandoned Ervedosa mine. The soil geochemical data show anomalies associated with mineralised veins or influenced by mining. Beyond the tailings, the highest recorded concentrations for most elements are in soils situated in mineralised areas or under the influence of tailings. The application of principal components analysis allowed recognition of (a) element associations according to their geochemical behaviour and (b) distinction between samples representing local geochemical background and samples representing contamination. Some metal cations (Mn, Cd, Cu, Zn, Co, Cr, Ni) showed important enrichment in the most mobilisable and bioavailable (i.e., water-soluble and exchangeable) fractions due likely to the acidic conditions in the area. In contrast, oxy-anions such as Mo and As showed lower mobility because of adsorption to Fe oxy-hydroxides. The residual fraction comprised largest proportions of Sn and Al and to a lesser extent Zn, Pb, Ni, Cr, Bi, W, and Ag, which are also present at low concentrations in the bioavailable fractions. The elements in secondary mineral phases (mainly Fe, Mn, Cu, Zn, Cd, Pb, W, Bi, Mo, Cr, Ni, Co, As and U) as well as in organic matter and sulphides are temporarily withheld, suggesting that they may be released to the environment by changes in physico-chemical conditions. 相似文献
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东天山-北山Cu- Ni- Au- Pb- Zn成矿带主要成矿地质特征及潜力分析 总被引：4，自引：0，他引：4
文章通过潜力评价成果汇总和综合分析,结合找矿新理论和该区找矿新进展,重新划定(修定)了东天山-北山Cu-Ni-Au-Pb-Zn重点成矿带的边界。东天山-北山Cu-Ni-Au-Pb-Zn重点成矿带位于西伯利亚板块和塔里木板块之间,在漫长的地质构造演化过程中经历了多次裂解、拼合、造山等构造运动,相应地发生过多期、多阶段的成矿作用,致使此带形成了众多不同矿种、不同类型的矿床,是矿产勘查突破的有利区带。作者从研究区构造演化历史出发,分析了该带区域成矿地质背景,结合带内最新的找矿进展,修订了东天山-北山Cu-Ni-Au-Pb-Zn重点成矿带的成矿谱系,深化了对本成矿带的成矿规律认识;新一轮矿产资源潜力评价证实,带内仍然具有极大的资源潜力,在此基础上,在本带划分了19个远景区,其中9个为重点远景区,10个为一般远景区;提出了带内可能发现新矿床类型(如:砂岩型铀矿、斑岩型金矿等)和新矿种(如稀有稀散金属等);建议本带下一步勘查部署的主攻矿种为Ni、Cu、Mo、Au、W,兼顾Pb、Zn、Ag、Fe和Mn;建议本带主攻类型为基性-超基性岩型镍铜矿、斑岩型铜(钼、金)矿、破碎蚀变岩型金矿、碳酸盐岩-细碎屑岩型铅锌银多金属矿、海相火山岩型铁矿、矽卡岩型银矿以及沉积型锰矿等。该项工作对指导本成矿带下一步矿产勘查部署工作有一定指导意义。 相似文献
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罗卜岭矿床是与晚中生代花岗闪长斑岩体有关的隐伏斑岩型铜钼矿床, 矿区位于紫金山矿田的东北部; 铜钼矿体主要产于绿泥石化-绢英岩化和(弱)钾化-绢英岩化带中, 矿石矿物组合为黄铜矿+辉钼矿; 少量过渡类型矿体产于高级泥化带中, 矿石矿物组合为蓝辉铜矿+铜蓝+辉钼矿。罗卜岭矿区的原生晕地球化学三维模型显示, 微量元素具有一定的分带特征, 低温元素Au与高温元素组合W、Sn、Bi分布于矿体上方, 中低温元素Pb、Zn、Ag分布于Cu、Mo元素之间; 元素直观垂向分带序列大致为: (As、Sb、Hg)-(W、Bi、Sn)-Ga-Au、Ba-Cu、Ag-Pb、Zn-Mn-Mo; 前缘晕的元素与氧化物组合为As、Sb、Au、Ga、Al2O3, 矿体近矿晕元素组合为Ag、Pb、Zn, 缺失尾晕元素组合; Cu、Mo可直接作为找矿指示元素, Au、Ag、Pb、Zn、As、Sb、Ga、Ba、Mn可作为间接指示元素, 矿床深部K2O正异常与Al2O3负异常可作为斑岩型铜钼矿的重要找矿标志, 这一规律对紫金山矿田深部和外围隐伏斑岩型矿体的勘查工作具有重要的参考意义。 相似文献
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浙江临安西天目地区地处早古生代扬子被动陆缘和晚中生代西太平洋活动陆缘构造叠加区域.该区发育碳酸盐岩建造,有大量的脉岩出露,环形、放射状断裂构造发育,具有面型蚀变及铜、铅、锌、金等多个矿（化）点;重磁等物探信息显示,该区深部发育EW向深断裂和隐伏岩体;化探扫面揭示,区内钨、钼、铋、铜、铅、锌、金、银、砷等元素背景高;自然重砂调查反映,白钨矿、铅族、钼族等重砂矿物组合具有异常显示.综合成矿地质条件及物、化、重砂异常等信息,认为该区具有寻找斑岩型、夕卡岩型、低温热液型钨、钼、铜、铅锌、金银等多位一体矿床的潜力. 相似文献
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Copper-Polymetal Metallogenic Series and Prospecting Perspective of Eastern Section of Gangdise 总被引：1，自引：0，他引：1
ZhengYouye XueYingxi GaoShunbao 《中国地质大学学报(英文版)》2003,14(4):349-355
Geological, geophysical, geochemical and remote sensing comprehensive studies show that big ore-prospecting potentiality is contained in the eastern section of the Gangdise Mountains, Tibet.There are various mineralization types with dominant types of porphyry and exhalation. According to their relations with tectonic evolution, they are divided into four kinds of metallogenic series as follows:magnmtic type (Cr, Pt, Cu, Ni) and exhalation type (Cu, Pb, Zn, Ag) ore deposit series related to Neo-Tethys oceanic crust subduction action (125-96 Ma); epithermai type (Au, Ag, Pb, Zn, Sb), altered fractured rock type (Cu, Mo) and skarn rock type (Cu) ore deposit series related to arc-continental collision; porphyry type (Cu, Mo), cryptoexplosion breccia type (Cu, Au, Pb, Zn), shear zone type (Au, Ag, Sb) and skarn rock type (Cu, Fe) ore deposit series with relation to post-orogenic extensional strike-slip. From subductive complex to the north, zoning appears to be crystallization differentiation type (segregation type)-shear zone type (altered rock type)-skarn rock type, epithermai type-porphyry type-porphyry type and exhalation type-exhalation type-hydrothermai filling-replacement type.The ore deposit is characterized by multi-places from the same source, parity and multi-stage, hypabyssal rock from the deep source and poly genetic compound as a whole. 相似文献
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The primary halos of porphyry copper deposits are characterized by compositional zoning in three dimensions. Two ideal zoning patterns can be divided in accordance with the shape of primary halos in space: bell-shaped and anticline-shaped. In the process of alteration-mineralization, K, Si, (OH), Fe, Cu, Mo, Ag, S, Ba, Rb, Pb, Zn, As, etc. were imported, while Na, Ca, Mg, Fe, Al, Ti, Mn, V, Co, Sr, Pb, Zn, etc. were exported or became activated, and then transported and reprecipitated. Both import and export of Fe, Pb and Zn may have taken place. The fundamental factors controlling the zoning of primary halos are: the stability of complexes and the activity of elements; pH, Eh, the behaviour of sulfur and the sulphophile character of elements; the concentration of components and the regularities of isomorphism; temperature and pressure; and tectonic setting and lithological characters of wallrocks. The authors consider that the zoning patterns of primary halos in porphyry copper deposits are the outcome of integrated effects of various factors. 相似文献
18.
Distribution and immobilization of heavy metals in Pliocene aquifer sediments in Wadi El Natrun depression, Western Desert 总被引：2，自引：0，他引：2
The Pliocene aquifer receives inflow of Miocene and Pleistocene aquifer waters in Wadi El Natrun depression. The aquifer also receives inflow from the agricultural activity and septic tanks. Nine sediment samples were collected from the Pliocene aquifer in Wadi E1 Natrun. Heavy metal (Cu, Sr, Zn, Mn, Fe, Al, Ba, Cr, Ni, V, Cd, Co, Mo, and Pb) concentrations of Pliocene aquifer sediments were investigated in bulk, sand, and mud fractions. The determination of extractable trace metals (Cu, Zn, Fe, Mn, and Pb) in Pliocene aquifer sediments using sequential extraction procedure (four steps) has been performed in order to study environmental pathways (e.g., mobility of metals, bounding states). These employ a series of successively stronger chemical leaching reagents which nominally target the different compositional fractions. By analyzing the liquid leachates and the residual solid components, it is possible to determine not only the type and concentration of metals retained in each phase but also their potential ecological significance. Cu, Sr, Zn, Mn, Fe, and Al concentrations are higher in finer sediments than in coarser sediments, while Ba, Cr, Ni, V, Cd, Co, Mo, and Pb are enriched in the coarser fraction. The differences in relative concentrations are attributed to intense anthropogenic inputs from different sources. Heavy metal concentrations are higher than global average concentrations in sandstone, USEPA guidelines, and other local and international aquifer sediments. The order of trace elements in the bulk Pliocene aquifer sediments, from high to low concentrations, is Fe?>?Al?>?Mn?>?Cr?>?Zn?>?Cu?>?Ni?>?V?>?Sr?>?Ba?>?Pb?>?Mo?>?Cd?>?Co. The Pliocene aquifer sediments are highly contaminated for most toxic metals, except Pb and Co which have moderate contamination. The active soluble (F0) and exchangeable (F1) phases are represented by high concentrations of Cu, Zn, Fe, and Mn and relatively higher concentrations of Pb and Cd. This may be due to the increase of silt and clay fractions (mud) in sediments, which act as an adsorbent, retaining metals through ion exchange and other processes. The order of mobility of heavy metals in this phase is found to be Pb?>?Cd?>?Zn?>?Cu?>?Fe?>?Mn. The values of the active phase of most heavy metals are relatively high, indicating that Pliocene sediments are potentially a major sink for heavy metals characterized by high mobility and bioavailability. Fe–Mn oxyhydroxide phase is the most important fraction among labile fractions and represents 22% for Cd, 20% for Fe, 11% for Zn, 8% for Cu, 5% for Pb, and 3% for Mn. The organic matter-bound fraction contains 80% of Mn, 72% of Cu, 68% of Zn, 60% of Fe, 35% of Pb, and 30% of Cd (as mean). Summarizing the sequential extraction, a very good immobilization of the heavy metals by the organic matter-bound fraction is followed by the carbonate-exchangeable-bound fraction. The mobility of the Cd metal in the active and Fe–Mn oxyhydroxide phases is the highest, while the Mn metal had the lowest mobility. 相似文献
19.
《International Geology Review》2012,54(16):1843-1869
Numerous molybdenum (Mo) ore deposits have been discovered in the East Xingmeng orogenic belt (East Central Asian orogenic belt), over the past 10 years, and this region is becoming one of the world's most important Mo production areas. It contains 6.18 Mt of proven Mo metal reserves, which accounts for 30% of the total proven Chinese Mo reserves. The ore district includes 37 deposits and 15 occurrences, with three major Mo ore types, that is porphyries, skarns, and hydrothermal veins. The latter can be subdivided into quartz- and volcanic hydrothermal-vein types. With the exception of the Ordovician Duobaoshan porphyry Cu–Mo deposit (477 Ma), all the East Xingmeng Mo deposits formed during the Mesozoic. Re–Os dating of molybdenite has documented three episodes of Mo mineralization: Early Triassic (248–242 Ma), Jurassic (178–146 Ma), and Early Cretaceous (142–131 Ma). Early Triassic Mo deposits are distributed along the northern margin fault of the North China Craton (NCC) and include porphyry and quartz vein types. They are characterized by the association of Mo + Cu. Jurassic Mo deposits are mainly distributed in the eastern area and include porphyry, quartz vein, and skarn types. They are typified by Mo alone and/or the association of Mo, Pb, and Zn. Cretaceous Mo deposits are distributed in all areas and include porphyry and volcanic hydrothermal vein types. Similar to the Jurassic ores, they are simple Mo or Mo + Pb + Zn deposits. Volcanic hydrothermal vein deposits are characterized by an association of molybdenum and uranium. The Triassic Mo deposits formed in a syn-collision setting between the Siberian and North China plates. The Jurassic Mo deposits formed in a compressional setting, which was probably triggered by the westward subduction of the palaeo-Pacific plate. The Early Cretaceous Mo deposits are linked to a tectonic regime of lithosphere thinning, which was caused by delamination of thickened lithosphere. However, the Mo deposits in the Erguna terrane of the northwest Xingmeng orogenic belt may be related to the evolution of the Okhotsk Ocean. 相似文献
20.
Many metallic ore deposits of the Late Cretaceous to Early Tertiary periods are distributed in the Gyeongsang Basin. Previous and newly analyzed sulfur isotope data of 309 sulfide samples from 56 ore deposits were reviewed to discuss the genetic characteristics in relation to granitoid rocks. The metallogenic provinces of the Gyeongsang Basin are divided into the Au–Ag(–Cu–Pb–Zn) province in the western basin where the sedimentary rocks of the Shindong and Hayang groups are distributed, Pb–Zn(–Au–Ag–Cu), Cu–Pb–Zn(–Au–Ag), and Fe–W(–Mo) province in the central basin where the volcanic rocks of the Yucheon Group are dominant, and Cu(–Mo–W–Fe) province in the southeastern basin where both sedimentary rocks of the Hayang Group and Tertiary volcanic rocks are present. Average sulfur isotope compositions of the ore deposits show high tendencies ranging from 2.2 to 11.7‰ (average 5.4‰) in the Pb–Zn(–Au–Ag–Cu) province, ?0.7 to 11.5‰ (average 4.6‰) in the Cu–Pb–Zn(–Au–Ag) province, and 3.7 to 11.4‰ (average 7.5‰) in the Fe–W(–Mo) province in relation to magnetite‐series granitoids, whereas they are low in the Au–Ag(–Cu–Pb–Zn) province in relation to ilmenite‐series granitoids, ranging from ?2.9 to 5.7‰ (average 1.7‰). In the Cu(–Mo–W–Fe) province δ34S values are intermediate ranging from 0.3 to 7.7‰ (average 3.6‰) and locally high δ34S values are likely attributable to sulfur derived from the Tertiary volcanic rocks during hydrothermal alteration through faults commonly developed in this region. Magma originated by the partial melting of the 34S‐enriched oceanic plate intruded into the volcanic rocks and formed magnetite‐series granitoids in the central basin, which contributed to high δ34S values of the metallic deposits. Conversely, ilmenite‐series granitoids were formed by assimilation of sedimentary rocks rich in organic sulfur that influenced the low δ34S values of the deposits in the western and southeastern provinces. 相似文献