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1.
滇东北巧家松梁铅锌矿床构造特征及构造地球化学   总被引:2,自引:0,他引:2  
巧家松梁铅锌矿床为川-滇-黔铅锌多金属成矿域内新发现的小型铅锌矿床,矿体产出严格受断裂构造的控制。在精细解剖矿区构造控矿特征的基础上,本文系统采集了不同中段的断裂构造岩并进行测试,通过因子分析方法讨论断裂构造地球化学元素组合特征,并绘制断裂构造地球化学异常-地质图,进行找矿预测。研究表明:该矿床不同中段断裂构造岩微量元素主要表现为地层岩石元素组合(Zr、Th、Rb、Ti、Hf、Be、∑REE、Sr、Sc、V、(U、Co))、铅锌矿化元素组合(Ga、Ag、Cd、Sn、Ge、Cu、Ba、In、Pb、(Zn))及中高温矿化元素组合(Mo、Co、Ni、(Mn)),而且不同矿体上部中段的构造岩因子元素组合相似,说明各矿体应为同一成矿流体作用而成,Ⅰ号矿体下部出现了方铅矿化和闪锌矿化元素组合因子的分离,可能反映了成矿流体组分的变化或是多阶段成矿流体叠加的缘故,各中段构造岩因子分析均表明重晶石化与铅锌成矿关系密切,这与野外地质现象相吻合,说明重晶石化是重要的找矿标志之一。构造地球化学异常的分布规律,不仅勾绘了矿体的产状,还反映了矿体显著受构造控制的特征,同时可以推测成矿流体的运移方向,并为找矿预测提供定位靶区。  相似文献   

2.
用构造地球化学方法对贵州烂泥沟金矿区主要控矿断裂F3断裂不同构造部位岩(矿)石进行研究,试图弄清控矿断裂与元素地球化学之间的关系。结果表明,在F3断裂控制的主矿体及其两侧断层破碎带中Au、Ag、As、Sb相对富集,且显著相关。由主矿体中心向两侧断层破碎带过渡,SiO2的显著减少,Fe2O3、Al2O3、CO2成分却显著增加。对比不同构造分带微量元素相关性,发现从简单变形带至断层破碎带,Au、Sb与其它微量元素的相关性明显减弱;As与Co、Ni、Cu、Ge、In、Ba、Tl的正相关性明显增强;Ag、Pb、Cu与微量元素的相关性也逐渐增大。断裂构造不但对金矿有显著控制,且对其它元素也有影响。  相似文献   

3.
滇西北兰坪盆地李子坪铅锌矿床微量元素地球化学特征   总被引:12,自引:0,他引:12  
闪锌矿中的稀土元素、微量元素蕴含着与成岩、成矿密切相关的地球化学信息.李子坪铅锌矿床位于兰坪盆地北部,矿体呈脉状、似层状产出于侏罗系花开佐组碎屑岩及碳酸盐岩夹泥质岩组合建造中.微量元素地球化学特征显示,该矿床闪锌矿形成于中低温环境,以富含 Ga、Ge、Ag、Cd、Tl、Ni、Cu 和 As 等微量元素,亏损 Fe、In、Sn、Mn 和 Co 等元素为特征.总体上,该矿床闪锌矿中 Ag、Ga 和 Fe 等微量元素组成明显不同于喷流沉积铅锌矿床(如白牛厂、老厂和大宝山),更不同于夕卡岩型矿床(如核桃坪与鲁子园),而与一般 MVT 型矿床(墨西哥 Tre Marias、云南会泽和贵州牛角塘)和金顶铅锌矿床类似,但 Cd 含量明显低于 MVT 型矿床和云南金顶铅锌矿床,暗示其独特的成矿机制.稀土元素研究显示,闪锌矿与赋矿围岩的REE 分布模式表现出相同的变化趋势,而不同于兰坪盆地富碱岩体,暗示该矿床闪锌矿的 REE 分布模式受围岩地层的影响.  相似文献   

4.
本文阐述了大硐厂铅锌矿床 Sn、Ag、Bi、Cd、Ga、In、Tl、Se、Te 的赋存状态。研究表明,矿床中的 Sn 以矿物相形式存在;Bi 以类质同象代替 Pb 进入方铅矿中,不含方铅矿时形成 Bi 的独立矿物;分散元素 Cd、Ga、In、Tl 主要赋存于铁闪锌矿中;Se、Te 主要赋存于方铅矿中,不含方铅矿时形成 Te 的独立矿物;Ge 则分散于造岩矿物中。划分了两个成矿阶段,指出了元素地球化学演化的规律性。  相似文献   

5.
清水塘铅锌矿床的成因及其找矿方向   总被引:1,自引:0,他引:1  
李石锦 《湖南地质》1993,12(1):35-40
清水塘铅锌矿床位于关帝庙岩体西南侧,赋存于寒武系上统及(?)陶系白水溪组中,有与地层整合的整合型似层状矿体和切层的脉带型矿体。矿石中除Pb、Zn、Cu、Fe外,尚有Ag、In、Sb、Ga、Ge等20多种元素。层位控制矿床的分布,岩性及断裂控制矿体产出。成矿元素组合,矿石包体特征及均一法测温结果和硫同位素组成等显示矿床属构造一热卤水再造成因。  相似文献   

6.
由于中国西南低温成矿域独特的地质成矿环境,从而形成了矿种齐全,不同规模的矿床组合,特别是大型和超大型金属矿床组合.它们包括Tl、Hg、As、Sb、Cu、Pb、Zn、Cd、Ge、Sn、Au和Ag等在内的一套亲铜族元素组合的系列矿床.在矿产资源紧缺的今天,研究它们的成矿和找矿问题尤显重要.基于对Tl的亲硫亲砷性质、区域地质成矿环境、表生地球化学循环和生物地球化学研究,本文以铊矿床为例,从铊(含铊)矿物、元素组合、多岩性岩、生物成矿和表生地球化学5个方面对铊(含铊)矿床找矿某些问题进行阐述.  相似文献   

7.
豫西栾川晚侏罗世中酸性岩浆热液活动形成了一套Mo-W(Fe)-Pb-Zn-Ag多金属成矿系列。其中骆驼山硫锌多金属矿床位于南泥湖矿田岩体的外接触带。在野外地质调查的基础上,通过ICP-MS对该矿床中闪锌矿/黄铁矿微量元素地球化学特征进行了详细研究。研究表明,矿床中闪锌矿微量元素的组成以富集Cd、In、Cu,亏损Ga、Tl为主要特征;Cd、In、Ga等分散元素主要赋存在闪锌矿中,Co、Ni主要富集在黄铁矿中。闪锌矿/黄铁矿中的∑REE含量均明显低于近矿围岩,早阶段闪锌矿轻重稀土元素分馏明显,配分曲线右倾;晚阶段闪锌矿LREE含量降低,配分曲线趋向平缓,并与晚阶段黄铁矿呈现互补性异常。闪锌矿的部分微量元素如Ga、Ge、Cd、In、Tl等能指示成矿温度、成矿流体特征及矿床成因,总体上闪锌矿微量元素组成特征与岩浆热液型矿床一致,与栾川中鱼库矿床成因相近,矿床形成于中高温环境。通过与邻区矿床对比分析,显示从成矿系列的过渡带到外围,成矿温度等特征呈规律性变化。  相似文献   

8.
针对矿区地表及井下四个中段共采集地层和构造蚀变岩样品194件,分析Ti、V、Cr、Mn、Co、Ni、Au、Ag、Cu、Pb、Zn、W、Sn、Mo、Bi、As、Sb、Hg等18种微量元素含量,编制各元素地球化学0号勘探线横剖面图,综合利用地球化学图件分析法与格里戈良分带指数法,确定元素的轴向分带序列。通过地质地球化学资料可知,石英闪长岩、构造蚀变岩中Cu、Ag、As、Au、Mo、Sn元素含量高,变异系数大,表明这些元素参与成矿蚀变作用。矿区原生晕轴向分带序列为:(Zn、Cr1、Hg1、Ni、As)→(Pb、V、Mn、W、Cr_2、Ti)→(Hg_2、Sb、Co、Bi、Sn、Ag、Au、Mo、Cu),根据元素地球化学横剖面图中主成矿元素异常高值带向下延伸未封闭、矿体向下未尖灭、特征前缘晕元素Hg、成矿晕元素Cu出现矿尾晕等特征,说明矿体向下仍有一定的延伸,预示着深部具有一定的找矿潜力。  相似文献   

9.
四川天宝山铅锌矿床硫化物微量元素组成:LA-ICPMS研究   总被引:20,自引:11,他引:9  
"川滇黔接壤铅锌矿集区"是我国西南大面积低温成矿域的重要组成部分,对于其中铅锌矿床是否属于MVT型矿床存在较大争议。本文以该矿集区中代表性矿床——四川天宝山矿床为例,通过LA-ICPMS原位元素分析,结合元素Mapping,以认识该矿床中闪锌矿和方铅矿微量元素组成特征及其赋存状态。研究表明,矿床中闪锌矿以富集Cd、Ge贫Fe、Mn、In、Sn、Co为特征,这些元素均以类质同象形式赋存于闪锌矿中,但含量变化范围较大,这可能与其成矿流体属于低温混合流体有关,这类盆地卤水流体在长期和长距离运移过程中,流经不同基底地层,活化出其中不同微量元素,因此成分变化较大,但以低温元素为主。此外,矿床中闪锌矿Ge和Cu呈现较好正相关关系,暗示其与Zn置换方式为:nC u~(2+)+Ge~(2+)(n+1)Zn~(2+),这可能是该矿床富集Ge的重要原因之一;矿床中方铅矿以富集Ag、Sb贫Bi为特征,含微量Cd和Tl,类质同象是这些元素主要赋存形式,其置换方式为(Ag)~(1+)+(Sb)~(3+)2Pb~(2+);矿床中Ge主要赋存于闪锌矿中,而方铅矿中不含Ge。总体上,本矿床硫化物微量元素组成与MVT型矿床基本一致,明显有别于喷流沉积型矿床、岩浆热液型矿床和远源夕卡岩型矿床,其成矿温度属于低温范围,成矿流体运移方向可能为深部→浅部。结合其矿床地质地球化学特征,本文认为天宝山铅锌矿床属于MVT型矿床,但其中闪锌矿中富集Cu,而方铅矿中富集Ag,可能暗示其形成具有一定特殊性。  相似文献   

10.
内蒙古浩布高铅锌矿床位于大兴安岭南段黄岗-甘珠尔庙成矿带,该带是我国北方重要的铅锌多金属成矿带之一。目前,浩布高矿床闪锌矿微量元素赋存机制尚不清晰,矿床成因类型亦存在一定的争议。本研究采用激光剥蚀电感耦合等离子体质谱仪(LA-ICP-MS)原位微量元素分析手段,结合机器学习方法,对浩布高闪锌矿微量元素组成特征、赋存机制以及矿床成因类型进行了探讨。LA-ICP-MS分析结果表明,浩布高矿床中闪锌矿以富集Fe、Mn、Co、Cu、Se、Ag、Cd、In、Sn等元素,贫Ni、Ga、Ge、As、Mo、Sb、Au、Tl、Pb、Bi等元素为特征。其中,Fe、Mn、In等元素主要以类质同象的方式替代Zn赋存于闪锌矿中,Cu、Ag、Sn等元素含量变化范围较大,可能部分以微粒包裹体的形式存在。In与Cu含量具有一定的正相关,推测In在闪锌矿中富集机理可能为Cu++In■3+2Zn2+。Cd与Fe含量呈一定的正相关性,而与Zn含量呈负相关性,这可能暗示在闪锌矿中Cd主要以类质同象的方式置换Zn元素而非Fe元素。通过穷举闪锌矿微量元素图解发现,...  相似文献   

11.
This paper reports the first results of a study of 11 isotope systems (3He/4He, 40Ar/36Ar, 34S/32S, 65Cu/63Cu, 62Ni/60Ni, 87Sr/86Sr, 143Nd/144Nd, 206–208Pb/204Pb, Hf–Nd, U–Pb, and Re–Os) in the rocks and ores of the Cu–Ni–PGE deposits of the Norilsk ore district. Almost all the results were obtained at the Center of Isotopic Research of the Karpinskii All-Russia Research Institute of Geology. The use of a number of independent genetic isotopic signatures and comprehensive isotopic knowledge provided a methodic basis for the interpretation of approximately 5000 isotopic analyses of various elements. The presence of materials from two sources, crust and mantle, was detected in the composition of the rocks and ores. The contribution of the crustal source is especially significant in the paleofluids (gas–liquid microinclusions) of the ore-forming medium. Crustal solutions were probably a transport medium during ore formation. Air argon is dominant in the ores, which indicates a connection between the paleofluids and the atmosphere. This suggests intense groundwater circulation during the crystallization of ore minerals. The age of the rocks and ores of the Norilsk deposits was determined. The stage of orebody formation is restricted to a narrow age interval of 250 ± 10 Ma. An isotopic criterion was proposed for the ore-bearing potential of mafic intrusions in the Norilsk–Taimyr region. It includes several interrelated isotopic ratios of various elements: He, Ar, S, and others.  相似文献   

12.
最新的流行病学研究表明,空气中较高浓度的悬浮细颗粒可能对人类的健康有不利的影响。根据该项研究显示,由于心脏病、慢性呼吸问题和肺功能指标恶化而导致死亡率的升高与细尘粒子有关。这些研究结果已经促使欧盟于1999年4月出台了限制空气中二氧化硫、二氧化氮、氧化氮、铅和颗粒物含量的法案(1999/30/EC),对各项指标包括对可吸入PM10颗粒的浓度提出了新的限制性指标。PM10颗粒是指可以通过预分级器分离采集的气体动力学直径小于10μm的细颗粒。目前研究的兴趣重点逐步偏向PM2.5这些更细微颗粒物,PM2.5这种颗粒物对健康有明显的不利影响。在欧盟指令2008/50/EC中,对PM10和PM2.5都提  相似文献   

13.
Komatiites are mantle-derived ultramafic volcanic rocks. Komatiites have been discovered in several States of India, notably in Karnataka. Studies on the distribution of trace-elements in the komatiites of India are very few. This paper proposes a simple, accurate, precise, rapid, and non-destructive wavelength-dispersive x-ray fluorescence (WDXRF) spectrometric technique for determining Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th in komatiites, and discusses the accuracy, precision, limits of detection, x-ray spectral-line interferences, inter-element effects, speed, advantages, and limitations of the technique. The accuracy of the technique is excellent (within 3%) for Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Zr, Nb, Ba, Pb, and Th and very good (within 4%) for Y. The precision is also excellent (within 3%) for Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th. The limits of detection are: 1 ppm for Sc and V; 2 ppm for Cr, Co, and Ni; 3 ppm for Cu, Zn, Rb, and Sr; 4 ppm for Y and Zr; 6 ppm for Nb; 10 ppm for Ba; 13 ppm for Pb; and 14 ppm for Th. The time taken for determining Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th in a batch of 24 samples of komatiites, for a replication of four analyses per sample, by one operator, using a manual WDXRF spectrometer, is only 60 hours.  相似文献   

14.
《Applied Geochemistry》2001,16(2):137-159
Five hundred and ninety-eight samples of terrestrial moss (Hylocomium splendens and Pleurozium schreberi) collected from a 188,000 km2 area of the central Barents region (NE Norway, N Finland, NW Russia) were analysed by ICP-AES and ICP-MS. Analytical results for Al, B, Ba, Ca, K, La, Mg, Mn, Na, P, Rb, Si, Sr, Th, U and Y concentrations are reported here. Graphical methods of data analysis, such as geochemical maps, cumulative frequency diagrams, boxplots and scatterplots, are used to interpret the origin of the patterns for these elements. None of the elements reported here are emitted in significant amounts from the smelting industry on the Kola Peninsula. Despite the conventional view that moss chemistry reflects atmospheric element input, the nature of the underlying mineral substrate (regolith or bedrock) is found to have a considerable influence on moss composition for several elements. This influence of the chemistry of the mineral substrate can take place in a variety of ways. (1) It can be completely natural, reflecting the ability of higher plants to take up elements from deep soil horizons and shed them with litterfall onto the surface. (2) It can result from naturally increased soil dust input where vegetation is scarce due to harsh climatic conditions for instance. Alternatively, substrate influence can be enhanced by human activity, such as open-cast mining, creation of ‘technogenic deserts’, or handling, transport and storage of ore and ore products, all of which magnify the natural elemental flux from bedrock to ground vegetation. Seaspray is another natural process affecting moss composition in the area (Mg, Na), and this is most visible in the Norwegian part of the study area. Presence or absence of some plant species, e.g., lichens, seems to influence moss chemistry. This is shown by the low concentrations of B or K in moss on the Finnish and Norwegian side of the (fenced) border with Russia, contrasting with high concentrations on the other side (intensive reindeer husbandry west of the border has selectively depleted the lichen population).  相似文献   

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《Chemical Geology》2007,236(1-2):13-26
We examined the coprecipitation behavior of Ti, Mo, Sn and Sb in Ca–Al–Mg fluorides under two different fluoride forming conditions: at < 70 °C in an ultrasonic bath (denoted as the ultrasonic method) and at 245 °C using a Teflon bomb (denoted as the bomb method). In the ultrasonic method, small amounts of Ti, Mo and Sn coprecipitation were observed with 100% Ca and 100% Mg fluorides. No coprecipitation of Ti, Mo, Sn and Sb in Ca–Al–Mg fluorides occurred when the sample was decomposed by the bomb method except for 100% Ca fluoride. Based on our coprecipitation observations, we have developed a simultaneous determination method for B, Ti, Zr, Nb, Mo, Sn, Sb, Hf and Ta by Q-pole type ICP-MS (ICP-QMS) and sector field type ICP-MS (ICP-SFMS). 9–50 mg of samples with Zr–Mo–Sn–Sb–Hf spikes were decomposed by HF using the bomb method and the ultrasonic method with B spike. The sample was then evaporated and re-dissolved into 0.5 mol l 1 HF, followed by the removal of fluorides by centrifuging. B, Zr, Mo, Sn, Sb and Hf were measured by ID method. Nb and Ta were measured by the ID-internal standardization method, based on Nb/Mo and Ta/Mo ratios using ICP-QMS, for which pseudo-FI was developed and applied. When 100% recovery yields of Zr and Hf are expected, Nb/Zr and Ta/Hf ratios may also be used. Ti was determined by the ID-internal standardization method, based on the Ti/Nb ratio from ICP-SFMS. Only 0.053 ml sample solution was required for measurement of all 9 elements. Dilution factors of ≤ 340 were aspirated without matrix effects. To demonstrate the applicability of our method, 4 carbonaceous chondrites (Ivuna, Orgueil, Cold Bokkeveld and Allende) as well as GSJ and USGS silicate reference materials of basalts, andesites and peridotites were analyzed. Our analytical results are consistent with previous studies, and the mean reproducibility of each element is 1.0–4.6% for basalts and andesites, and 6.7–11% for peridotites except for TiO2.  相似文献   

18.
Most sulfide-rich magmatic Ni-Cu-(PGE) deposits form in dynamic magmatic systems by partial melting S-bearing wall rocks with variable degrees of assimilation of miscible silicate and volatile components, and generation of barren to weakly-mineralized immiscible Fe sulfide xenomelts into which Ni-Cu-Co-PGE partition from the magma. Some exceptionally-thick magmatic Cr deposits may form by partial melting oxide-bearing wall rocks with variable degrees of assimilation of the miscible silicate and volatile components, and generation of barren Fe ± Ti oxide xenocrysts into which Cr-Mg-V ± Ti partition from the magma. The products of these processes are variably preserved as skarns, residues, xenoliths, xenocrysts, xenomelts, and xenovolatiles, which play important to critical roles in ore genesis, transport, localization, and/or modification. Incorporation of barren xenoliths/autoliths may induce small amounts of sulfide/chromite to segregate, but incorporation of sulfide xenomelts or oxide xenocrysts with dynamic upgrading of metal tenors (PGE > Cu > Ni > Co and Cr > V > Ti, respectively) is required to make significant ore deposits. Silicate xenomelts are only rarely preserved, but will be variably depleted in chalcophile and ferrous metals. Less dense felsic xenoliths may aid upward sulfide transport by increasing the effective viscosity and decreasing the bulk density of the magma. Denser mafic or metamorphosed xenoliths may also increase the effective viscosity of the magma, but may aid downward sulfide transport by increasing the bulk density of the magma. Sulfide wets olivine, so olivine xenocrysts may act as filter beds to collect advected finely dispersed sulfide droplets, but other silicates and xenoliths may not be wetted by sulfides. Xenovolatiles may retard settling of – or in some cases float – dense sulfide droplets. Reactions of sulfide melts with felsic country rocks may generate Fe-rich skarns that may allow sulfide melts to fractionate to more extreme Cu-Ni-rich compositions. Xenoliths, xenocrysts, xenomelts, and xenovolatiles are more likely to be preserved in cooler basaltic magmas than in hotter komatiitic magmas, and are more likely to be preserved in less dynamic (less turbulent) systems/domain/phases than in more dynamic (more turbulent) systems/domains/phases. Massive to semi-massive Ni-Cu-PGE and Cr mineralization and xenoliths are often localized within footwall embayments, dilations/jogs in dikes, throats of magma conduits, and the horizontal segments of dike-chonolith and dike-sill complexes, which represent fluid dynamic traps for both ascending and descending sulfides/oxides. If skarns, residues, xenoliths, xenocrysts, xenomelts, and/or xenovolatiles are present, they provide important constraints on ore genesis and they are valuable exploration indicators, but they must be included in elemental and isotopic mass balance calculations.  相似文献   

19.
This paper discusses the result of the detailed investigations carried out on the coal characteristics, including coal petrography and its geochemistry of the Pabedana region. A total of 16 samples were collected from four coal seams d2, d4, d5, and d6 of the Pabedana underground mine which is located in the central part of the Central-East Iranian Microcontinent. These samples were reduced to four samples through composite sampling of each seam and were analyzed for their petrographic, mineralogical, and geochemical compositions. Proximate analysis data of the Pabedana coals indicate no major variations in the moisture, ash, volatile matter, and fixed carbon contents in the coals of different seams. Based on sulfur content, the Pabedana coals may be classified as low-sulfur coals. The low-sulfur contents in the Pabedana coal and relatively low proportion of pyritic sulfur suggest a possible fresh water environment during the deposition of the peat of the Pabedana coal. X-ray diffraction and petrographic analyses indicate the presence of pyrite in coal samples. The Pabedana coals have been classified as a high volatile, bituminous coal in accordance with the vitrinite reflectance values (58.75–74.32 %) and other rank parameters (carbon, calorific value, and volatile matter content). The maceral analysis and reflectance study suggest that the coals in all the four seams are of good quality with low maceral matter association. Mineralogical investigations indicate that the inorganic fraction in the Pabedana coal samples is dominated by carbonates; thus, constituting the major inorganic fraction of the coal samples. Illite, kaolinite, muscovite, quartz, feldspar, apatite, and hematite occur as minor or trace phases. The variation in major elements content is relatively narrow between different coal seams. Elements Sc,, Zr, Ga, Ge, La, As, W, Ce, Sb, Nb, Th, Pb, Se, Tl, Bi, Hg, Re, Li, Zn, Mo, and Ba show varying negative correlation with ash yield. These elements possibly have an organic affinity and may be present as primary biological concentrations either with tissues in living condition and/or through sorption and formation of organometallic compounds.  相似文献   

20.
Sulfide minerals in the Boulder batholith occur 1. as disseminated grains, visible in hand specimens; 2. in aplitic-pegmatitic pods and masses; 3. along joint and shear surfaces; 4. in hydrothermal veins; and 5. as minute masses within pyrite and silicate minerals and along intergranular sites. Hydrothermally altered rocks have an average sulfide content of 0.8 weight per cent, compared to an average of 0.01 per cent for unaltered rocks. Unaltered rock of the batholith may contain as much as 0.7 weight per cent sulfide. Sulfide inclusions in pyrite, the most abundant sulfide of the batholith, are common and represent a captured iss-phase which later changed to chalcopyrite plus pyrrhotite or mackinawite. Inclusions are most abundant, and more complex, in pyrites of hydrothermally altered and ore rocks. Electron-probe analyses show that pyrites of the Boulder batholith have very similar compositions to those found for pyrites from other ore deposits around the world.  相似文献   

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