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1.
峨眉山大火成岩省Ni-Cu-PGE矿床可以区分出在成矿元素组成上不同的矿化类型,其中金宝山和力马河两个矿床分别代表富铂族元素和贫铂族元素的两种极端类型,金宝山铂钯矿贫铜镍富铂钯,硫化物含量低、呈浸染状;力马河镍矿贫铂族元素,富含硫化物、矿石以陨铁状或块状为主.岩石地球化学研究已表明,两个矿床成矿岩体岩石地球化学特征基本相同,都是峨眉山大火成岩省玄武质岩浆分异演化的产物,是什么原因造成了矿床成矿元素组成的变化和矿石结构类型的显著差异?对这一问题的探讨,有助于对峨眉山大火成岩省Ni-Cu-PGE成矿作用的系统认识.本文从硫同位素组成特征上对这两个矿床进行了对比分析.  相似文献   

2.
广东梅县玉水多金属矿矿床成因探讨   总被引:3,自引:0,他引:3  
本文在对比分析矿区火成岩(围岩)及含矿段岩矿石稀土元素、微量元素的基础上,结合矿石稳定同位素及包裹体特征对矿床成因作了探讨。根据本区微量元素性状及其分布特征,指出了含矿段火成岩与矿区内脉状火成岩侵人体(β_μ及γ_π)及上侏罗统火成岩的微量元素特征差异,同时认为:矿床是由局部火山喷气并受中温热液改造而成,含矿段矿化火山岩是由特定火山喷气作用形成的产物,它与区内的脉状火成岩侵人体及上侏罗统火山岩之间没有成因联系,对矿床改造作用的中温热液,主要来自深部隐伏碱性侵人体。  相似文献   

3.
三道明水矿床位于北山成矿带的西部,是近年来新发现的一个中型Cu-Zn矿。为了解该矿床成因类型及主要控矿因素,本文在前期勘探工作的基础之上,对其矿床地质特征,特别是蚀变矿化特征开展了野外及室内研究。根据热液蚀变、矿物组合及脉体间穿插关系的不同,可将三道明水矿床的蚀变和矿化划分为早、中、晚3期。其中,早期矿化以黄铁矿±黄铜矿±闪锌矿、黄铁矿-闪锌矿±黄铜矿组合,以及零星浸染状黄铁矿-黄铜矿-闪锌矿组合为特征,相关的热液蚀变为绿泥石±绢云母,显示出块状硫化物矿床的蚀变矿化特征;中期矿化为该矿床的主要成矿阶段,以浸染状黄铜矿-闪锌矿-黄铁矿组合为特征,相关蚀变为绢英岩化,含Cu、Zn矿物(黄铜矿、闪锌矿)形成于韧性变形过程中;晚期矿化主要以石英±黄铜矿±辉钼矿脉±黄铁矿脉、方解石脉发育为特征,蚀变不明显。基于上述蚀变矿化特征的观察,并通过与区域成矿作用的综合对比,认为三道明水矿床早期可能为块状硫化物型(VMS)矿化,中期经历了韧性剪切变形驱动下的热液改造,在主剪切带富集形成了工业矿体,晚期叠加了岩浆热液有关的Cu-Mo矿化。  相似文献   

4.
李建忠  刘宇平  沈战武 《地质学报》2012,86(12):1972-1993
通过野外填图、坑探和钻探以及室内测试、研究认为:黑牛洞铜锌矿床原来可能是一个形成于中元古代大陆被动边缘裂谷的大型甚至特大型海相火山块状硫化物矿床;含矿围岩是糜棱岩、千糜岩、糜棱片岩、变晶糜棱岩、变粒岩、浅粒岩和构造蚀变岩,剪切型矿化和蚀变带包裹了矿体,原岩是石英砂岩、泥质石英粉砂岩、泥质岩和硅质岩夹基性火山岩、少量中—酸性、酸性火山岩,经过变质达到高绿片岩相—低角闪岩相.以块状、角砾状和准块状矿石为主的矿床是富铜矿,矿石的铜平均品位为1.68%,锌品位平均为1.53%;矿化与褪色带、硅化关系密切.矿化类型以广泛发育韧性剪切带型浸染状矿化岩或矿石(分别简称剪切型矿化岩或矿石)为特色,具有与糜棱岩、千糜岩相同的变形特征,可见两期以上的金属矿物透镜体、变形条带和不协调微褶皱.矿床具有原地韧性变形改造、变质再生矿床的特点;矿石、矿体的围岩和氢、氧、硫、铅、硅同位素特征显示,块状、准块状和角砾状矿石的矿质基本来源于剪切型矿化岩或矿石,是变质生成矿床,也是原矿石的再生矿床,而剪切型矿化岩或矿石可能是中元古代海底火山-裂谷作用形成的火山块状硫化物矿床经过多期韧性变形、变质改造形成的,是溶解为主的化学再活化的残余.构造改造、再生矿床的成矿时代为134.26±0.5Ma.,形成于燕山晚期.  相似文献   

5.
东升庙矿床成因和找矿研究   总被引:1,自引:0,他引:1  
对内蒙古东升庙矿床的矿床地质、地球化学特征的研究显示,该矿床的富硫和富锌2种矿体在矿体形态、矿石的金属矿物组合、结构构造、围岩蚀变特征及稀土元素地球化学特征方面均显示明显的差异.矿床的成矿作用有2期:第一期为热水喷流-沉积作用,形成了富硫矿体;第二期为发生于区域变质和变形作用之后的低温热液改造成矿作用,形成了富锌矿体.该矿床含矿地层从上到下多层富硫矿体-碎屑岩-白云质大理岩的岩石组合及富硫矿体形成以后的热液活动是形成富锌矿体的必要条件.在该矿床及其外围的狼山-渣尔泰成矿带内,众多块状硫化物矿床原生矿体之下、或多金属沉积层之下,有可能找到改造型富铜、锌、铅矿体.  相似文献   

6.
祁连山拉水峡铜镍硫化物矿床矿物学、地球化学及成因   总被引:1,自引:0,他引:1  
谢燮 《地质与勘探》2014,50(4):617-629
拉水峡中型铜镍矿床几乎全岩矿化。矿石矿物学、矿床地球化学的研究表明,矿石中金属硫化物以紫硫镍铁矿、黄铁矿、黄铜矿为主,热液作用使原生硫化物组合发生了改变,低温热液特征的元素As、Se、Ag、Te富集; 矿石中Ni含量远高于Cu含量,不同类型矿石均属轻稀土富集型,反映了相同的岩浆成因,部分熔融来源特点。热液改造致使块状矿石中Cu/Ni、Ni/Co比值较高,REE分馏程度明显高于原生浸染状矿石;矿石中铂族元素含量平均为2460.5×10-9,具有较高的Ir含量和低的Pd/Ir比值特点,铂族元素与岩浆深部融离作用密切相关,块状矿石Pd/Ir比值和(Pt+Pd)/(Os+Ir+Ru)比值均高于原生浸染状矿石,表明热液作用对Cu、Pt、Pd金属元素富集具有一定作用;岩浆期后流体属中低温度(180~244℃)、中等盐度(8.81~14.67%NaCl)、中等密度(0.86~0.95g/cm3)范围, CH4+N2+CO2成分组合,具有岩浆流体成分特征。综合分析认为,拉水峡矿床主体成因可能仍以岩浆深部曾有过较彻底的硫化物不混熔作用为主,后期经历了热液作用改造。  相似文献   

7.
新疆叶城叉路口铅锌矿是喀喇昆仑北麓的叶尔羌河上游的一处中型铅锌矿床。铅锌矿体产于神仙湾二叠-三叠纪边缘裂陷带的中-下二叠统神仙湾组上段中,矿体的围岩有碎裂状的粉砂质板岩、白云质大理岩、泥晶灰岩,以及构造角砾岩等,铅锌矿体受断裂及碎裂化岩石的控制,矿体主要呈层状、似层状或大透镜状,但也有小型脉状含矿石英脉穿切层理,矿石构造有条纹-条带状、块状构造、团块状、斑点状、浸染状构造,矿物组合显示简单硫化物组合特点,围岩蚀变主要有硅化、绿泥石化和碳酸盐化,蚀变强度较弱。铅锌矿床特征既反映出沉积成矿的某些特点,也显示出后期热液成矿的许多特征,在综合对比区域铅锌矿成矿规律之后认为,叉路口铅锌矿的矿床成因为沉积-热液改造型铅锌矿床,属于复因-后成矿床范畴。  相似文献   

8.
高松山金矿床位于中国东北小兴安岭矿集区,赋矿围岩主要为下白垩统安山岩等中基性火山岩。矿体受张性断裂的控制,呈高角度脉状产出。矿石中金属矿物主要为黄铁矿和少量的黄铜矿、方铅矿、闪锌矿、自然金和银金矿。蚀变矿物组合为石英-冰长石-绢云母(伊利石)-方解石。矿石构造主要为细脉-网脉状构造,次为角砾状构造、浸染状构造、叶片状构造等。成矿流体具有低温、低盐度的特征,主要来源于大气降水,C-S-Pb同位素组成表明成矿物质主要来源于赋矿火山岩或岩浆气体。通过与东北地区其他典型的中生代浅成低温热液型金矿床特征进行对比,地质地球化学特征支持高松山金矿床属于典型的低硫化型浅成低温热液金矿床。  相似文献   

9.
内蒙古西乌珠穆沁旗阿拉坦高勒钒钛磁铁矿矿床地质特征   总被引:2,自引:2,他引:0  
在内蒙古西乌旗阿拉坦高勒地区新发现了一个品位低、出露浅、规模大的钒钛磁铁矿矿床。其含矿母岩主体为辉长岩,其次有部分闪长岩、角闪辉长岩和橄榄辉长岩等岩石类型。钻孔岩心岩相学研究表明,基性程度高的橄榄辉长岩通常在含矿岩体的中下部,基性程度低的闪长岩通常在含矿岩体的上部及边部。矿石矿物组合主要为磁铁矿、含钒磁铁矿、钛磁铁矿、黄铁矿、黄铜矿及少量金红石。其中,磁铁矿、含钒磁铁矿和钛磁铁矿通常呈海绵陨铁状、浸染状及分散星点状分布在硅酸盐矿物粒间,表现出典型的岩浆熔离和结晶分异的结构特点,与四川攀枝花铁矿有一定的相似性。与传统的岩浆矿床不同的是,新发现的富矿体通常位于岩体的上部,且普遍发育围岩蚀变。研究认为后期热液叠加对现今矿床的形成与改造起到了一定的作用。  相似文献   

10.
金宝山铂钯矿和四川力马河镍矿是峨眉山大火成岩省内两个重要的Ni-Cu-PGE硫化物矿床,但二者矿化特征明显不同,前者贫铜、镍,富铂、钯,硫化物含量低,呈浸染状;后者贫铂族元素,富含硫化物,矿石以陨铁状或块状为主.本文以两矿床成矿元素组成的变化和矿石结构类型的显著差异为出发点,系统分析了硫化物的硫同位素,发现金宝山铂-钯矿的硫化物δ34S值(0.6‰~2.8‰)略高于地幔硫(0±2‰),显示有微弱的地壳物质混染,而力马河镍矿的硫化物δ34S值(2.4‰~5.4‰)显著高于金宝山铂-钯矿,反映受地壳混染程度较高;指出成矿岩浆演化过程中地壳混染程度上的差异,可能是造成峨眉山大火成岩省岩浆Ni-Cu-PGE矿床矿化类型不同的重要原因.通讯作者  相似文献   

11.
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   

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.
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   

14.
本文介绍样品经四硼酸锂熔融制成玻璃小饼。采用Lachance模式和理论a系数来校正元素间的效应,由3080E型X-射线荧光谱仪和DF-350B数据处理系统完成硅酸盐中十三个项目的测定。  相似文献   

15.
本文拟定了一种以熔融法制备样片,用X射线荧光光谱测定硅酸盐类样品中Si、Fe、Al、Tj、Mn、Ca、Mg、K、Na、P等元素的分析方法。在对不同靶材X光管和分光晶体实验对比的基础上,选择了最佳的测量条件。该法具有快速、准确,测量范围广,检测限低,价格便宜等优点。经过近百个各种类型标样或管理样品的分析对比表明,本法不仅适用于硅酸盐类岩石样品的分析,还适用于铁矿、铝土矿、碳酸盐类岩矿样品以及水泥、耐火材料等样品的分析。  相似文献   

16.
Mining induced subsidence can significantly affect mining costs where major surface facilities and natural environment need to be protected. Overburden grout injection is a technology used to control coal mine subsidence by injecting the mine waste material extracted from the coal back into the inter-burden rock during longwall mining. The flowing slurry is here categorised as a nonlinear viscous cohesive (Bingham plastic) fluid. During longwall mining the grout slurry is pumped into the separated beds of the rock mass through a central vertical borehole, which is drilled deep into the inter-burden rock strata above the coal seam. However, a blockage can occur in the injection system when the slurry velocity falls below a certain critical threshold velocity, indicating a material phase change from cohesive-viscous to cohesive-frictional. In situ field injection tests through boreholes have been simulated at a smaller scale at the CSIRO laboratory in Brisbane by pumping the slurry through a radial disk (gap = 4 mm) from its centre. Laboratory experiments indicate a general, nonlinear, cohesive, viscous, frictional model for shear behaviour of the slurry, in which the material shear parameters are functions of the disk radial distance. Complete dimensional and dimensionless analytical solutions have been developed based on an approach related to Bingham–Herschel–Bulkley fluid mechanics. The derived formulae include relations for minimum pump pressure, local pressure and pressure gradient, wall shear stress, volume rate, velocity and velocity gradient. The theoretical results match the experimental measurements. The experiments covered slurries with maximum particle sizes of 0.5 to 2 mm with about 50% being larger than 100 µm. The viscosities at the various solids concentrations were measured with a standard torsion viscometer. This study differs from the previous research in several distinct aspects, namely, consideration of the variable shear parameters rather than fixed values, inclusion of total nonlinear behaviour, and implementation of a friction function to mimic behaviour of the deposited and consolidating stiff slurry, which can cause a significant pressure rise as a result of the increased shear resistance.  相似文献   

17.
18.
Between 1985 and 1991, two new mountain protected areas (MTNPA) covering more than 35,000 km2 and based on participatory management models — the Makalu-Barun National Park and Conservation Area, Nepal, and Qomolangma Nature Preserve, Tibet Autonomous Region — were successfully established through the collaborative efforts of Woodlands Mountain Institute and conservationists in China and Nepal. Characteristics common to both projects include the importance of establishing (1) effective rationales, (2) local support constituencies, (3) a senior advisory group, (4) a task force, (5) linkages between conservation and development, and (6) fund raising mechanisms. The lessons derived from the experiences of Woodlands Mountain Institute are of significant value to others in preserving MTNPA. Increased collaboration and communication between all interested in conservation, however, will remain a critical component for expanding mountain protected area coverage to throughout the world.  相似文献   

19.
岩石密度和超高压岩石折返速率   总被引:1,自引:3,他引:1  
在常温常压条件下对中国大陆科学钻CCSD主孔100-3000米岩心样品进行了密度测量,建立了密度连续剖面,并界定了不同超高压岩石的密度值。通过对比高温高压物性实验资料,岩石密度随着退变程度增强而降低,榴辉岩密度变化序列为3.52g/cm3→3.49g/cm3→3.07g/cm3→2.93g/cm3。超高压长英质岩石密度变化序列为3.00g/cm→2.80g/cm3→2.65g/cm3。上述实验资料是讨论不同折返阶段岩石所受浮力的基础,为研究折返速率大小提供了基本参数。本文通过折返板块运动平衡时,上浮力与粘滞力平衡这一关系式,定量研究了大陆俯冲板块的折返速率,认为密度差产生上浮力从而引起折返,温度对板块折返速率的影响最为显著;密度差大小、折返角度、折返板块大小对折返速率也有直接的影响。定量模拟分析表明,在温度高于850℃时,板块的折返速率可以超过100mm/a;当温度降至700℃时,折返速率则低于1.5mm/a。作者认为在折返早期,温度较高,板块快速折返至60-70km榴辉岩相深度;随着传导散热,温度降低,板块以较慢的速率折返至中下地壳。折返速率的估算表明,浮力是板块折返第一阶段(从>100km深部折返至<40km的中下地壳)的主要驱动力。  相似文献   

20.
《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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