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1.
滇东北茂租铅锌矿床赋存于震旦系灯影组白云岩中,矿体呈似层状、脉状和不规则状,矿石主要由黄铁矿、闪锌矿、方铅矿、方解石和白云石等组成。方解石是该矿床中最为主要的脉石矿物,其形成贯穿整个成矿过程。本文选择与硫化物紧密共生的团斑状方解石为研究对象,借助等离子体质谱仪(ICP-MS),获得了5件热液方解石的稀土元素含量数据。结果显示,全部样品的总稀土元素含量较低(ΣREE=19.56×10-662.55×10-6),轻、重稀土元素间分异较明显[ΣLREE/ΣHREE=1.3062.55×10-6),轻、重稀土元素间分异较明显[ΣLREE/ΣHREE=1.3010.83,(La/Yb)N=2.8310.83,(La/Yb)N=2.8331.40]。全部样品的(La/Sm)N(0.9231.40]。全部样品的(La/Sm)N(0.926.30)和(Gd/Yb)N(3.086.30)和(Gd/Yb)N(3.085.24)值表明轻稀土和重稀土元素内部分异不显著,δEu=1.875.24)值表明轻稀土和重稀土元素内部分异不显著,δEu=1.874.27,呈明显的Eu正异常特征,而δCe=0.834.27,呈明显的Eu正异常特征,而δCe=0.831.18,显示Ce异常特征不明显。茂租铅锌矿床中热液方解石稀土元素含量、配分模式及相关参数与赋矿围岩灯影组白云岩不同,与区域上不同时代地层沉积岩及二叠纪峨眉山玄武岩也不同,但与会泽超大型铅锌矿床中的团斑和脉状热液方解石相似,暗示茂租铅锌矿床成矿流体中的REE来源与可能会泽矿床相似。结合同标本的C-O同位素组成和Sm-Nd同位素年龄,认为茂租铅锌矿床形成于晚三叠纪(196±13 Ma),其成矿流体中的不同组分具有不同的来源,可能与川滇黔铅锌矿床属于同构造热事件的产物,与VMS、SEDEX和MVT型不同,暂归为川滇黔型。  相似文献   

2.
本文旨在对江西省全南县青龙山萤石矿床的地球化学特征及成因进行探讨,通过对青龙山萤石矿区矿石和围岩样品进行稀土元素分析,青龙山萤石矿矿石的∑REE平均含量为88.186×10-6,δEu为0.23~0.61,δCe为0.78~0.91;围岩的∑REE平均含量为184.52×10-6,δEu为0.31~0.69,δCe为0.85~1,萤石矿石和围岩的稀土元素配分模式具有相似性和同步性,呈轻稀土相对富集的右倾型,Eu中等亏损,Ce弱亏损。矿石与围岩的稀土地球化学研究显示,该萤石矿床至少存在两个成矿期次,为岩浆热液成矿,成矿环境为稳定的较还原条件,成矿流体温度在200℃左右。  相似文献   

3.
浙江八面山萤石矿床稀土元素地球化学特征及成因探讨   总被引:4,自引:2,他引:2  
对浙江八面山萤石矿床中不同类型萤石矿石和围岩样品的稀土元素的系统分析表明,细粒萤石矿石的ΣREE〈39×10-6,LREE为14.36×10-6~34.24×10-6,HREE0.96×10-6~2.04×10-6,Y〈3×10-6;巨晶萤石矿石中的ΣREE3.62×10-6~20.81×10-6,LREE2.71×10-6~17.67×10-6,HREE0.24×10-6~1.49×10-6;而围岩花岗岩的ΣREE460.29×10-6,LREE225.97×10-6,HREE91.32×10-6,Y>140×10-6;沉积岩中的ΣREE20.22×10-6、LREE16.11×10-6、HREE1.61×10-6。矿石与围岩中沉积岩的稀土总量、轻稀土、重稀土和Y的含量接近,与花岗岩的稀土总量、轻稀土、重稀土和Y元素含量相差悬殊。萤石矿石的稀土分布型式主要为轻稀土富集型,(La/Yb)N通常多数大于8,在8.07~17.26间,δEu值在0.45~1.30,δCe在0.89~1.14间,Ce、Eu基本不显异常。矿石与围岩的稀土地球化学研究显示,八面山萤石矿床为受地层、岩体与断裂共同控制"三位一体"的低温热液型矿床。  相似文献   

4.
通过对罗平富乐铅锌矿区地层及矿石进行了稀土元素地球化学特征对比研究.结果显示,梁山组样品 ΣREE值25.91×10-6~108.40×10-6,δEu值0.35~0.73,δCe值0.64~1.35.具Eu负异常和Ce弱正异常;阳新组碳酸盐岩样品 ΣREE值0.82×10-6~6.75×10-6,δEu值0.15~0.97,δCe值0.22~0.62,具Eu负异常和Ce负异常;玄武岩样品 ΣREE值204.17×10-6~290.57×10-6,δEu值变化范围0.91~0.97,δCe值1.02~1.03,Eu异常和Ce异常不明显.峨眉山玄武岩、阳新组、梁山组岩石与矿石REE配分模式比较区别明显,暗示成矿物质并非这些地层提供另有其它来源;梁山组及含矿地层阳新组样品为轻稀土富集型,并具有Eu负异常,暗示地层可能形成于被动大陆边缘还原环境.  相似文献   

5.
《四川地质学报》2022,(3):375-382
对松树南沟金矿区大面积出露的玄武安山岩进行了年代学和地球化学研究,厘定了成岩时代探讨了岩石形成的构造环境。研究表明,玄武安山岩中岩浆锆石LA-MC-ICP-MS U-Pb加权平均年龄为450±2 Ma,MSWD=1.8,属晚奥陶世。主量元素显示玄武安山岩样品Si O2含量介于51.1%55.4%,平均52.8%,属中-基性的钙碱性火山岩。岩石稀土总量较低,ΣREE为29.6×10-655.4%,平均52.8%,属中-基性的钙碱性火山岩。岩石稀土总量较低,ΣREE为29.6×10-6163.8×10-6,平均114.2×10-6。岩石的(La/Yb)N为3.70163.8×10-6,平均114.2×10-6。岩石的(La/Yb)N为3.7012.17,平均7.73,显示出轻稀土元素相对富集、重稀土元素相对亏损的特征。样品δEu为0.6112.17,平均7.73,显示出轻稀土元素相对富集、重稀土元素相对亏损的特征。样品δEu为0.610.89,平均0.78,具有弱的负铕异常。微量元素显示出富集大离子亲石元素(Rb、Th、U),相对亏损Nb、Ta、Ti,无明显的Zr和Hf异常,具有岛弧玄武岩的地球化学特征。该文认为松树南沟金矿区玄武安山岩形成于北祁连洋向南侧中祁连陆块俯冲的构造环境,其成因可能与洋壳俯冲环境下流体交代的岩石圈地幔部分熔融有关。  相似文献   

6.
那哥铜多金属矿床是江南古陆西南端黔东南地区多金属矿床的典型代表。该矿床产于新元古界地层中,受近东西向构造控制,与辉绿岩空间接触。利用ICP-MS,本文系统获得了该矿床矿石、赋矿围岩、外围花岗岩和隐伏花岗斑岩的REE组成,结果显示矿石具有变化的总稀土含量(∑REE=6.61×10-6~235×10-6)、轻稀土富集和负Eu异常(δEu=0.59~0.88)特征;赋矿围岩∑REE值范围较宽,介于74.2×10-6~286×10-6,并具有轻稀土富集和负Eu异常(δEu=0.79~0.88)特征;辉绿岩∑REE值介于78.1×10-6~90.9×10-6,较为稳定,为轻稀土富集和不明显的Eu异常特征(δEu介于0.98~1.01);花岗岩总稀土含量稳定(∑REE=132×10-6~193×10-6),具有轻稀土富集和明显的Eu负异常特征(δEu介于0.55~0.79);新发现隐伏花岗斑岩∑REE=74.9×10-6~120×10-6,具有轻稀土明显富集和显著的Eu负异常(δEu=0.44~0.56)。对比研究认为,那哥铜多金属矿床成矿流体中的REE主要继承围岩,表明部分成矿物质由赋矿地层岩石提供。  相似文献   

7.
杨山萤石矿床是豫西栾川地区一处大型花岗岩容矿型矿床,其成矿期次和成矿流体特征研究的不足长期制约着对萤石淀积机理和区域成矿规律的深化认识。本文基于杨山矿床萤石的稀土元素及流体包裹体研究,阐释了成矿物质来源、成矿流体属性及矿床成因。第Ⅱ阶段萤石的ΣREE含量为22.61×10-6~287.94×10-6,LREE/HREE比值为0.64~5.24,具Eu负异常(δEu=0.50~0.92)和Ce负异常(δCe=0.88~1.06)。随成矿深度的增大,萤石ΣREE减小,LREE/HREE和LaN/YbN增大,δEu和δCe无明显变化,指示总体成矿先后顺序为地下深部至地表浅部,且垂向上氧逸度较稳定。从紫色萤石到绿色萤石,ΣREE增大,LREE/HREE和LaN/YbN减小,δEu和δCe增大,表明萤石具有重新活化和重结晶的趋势。萤石的流体包裹体以气液两相为主,均一温度集中于80~155℃,盐度(NaCleqv.)集中于0.3%~6.3%。综合...  相似文献   

8.
黔北桑木场背斜灯影组热液白云岩稀土元素地球化学特征   总被引:1,自引:0,他引:1  
王珏  刘金海  陈云明 《贵州地质》2013,(2):132-135,146
本文利用电感耦合等离子体质谱仪,分析了习水桑木场背斜核部铅锌矿赋矿热液蚀变白云岩的稀土元素组成,并初步探讨了白云岩化与铅锌矿化间的关系。铅锌矿体旁侧工程中白云岩样品的测试显示:有部分样品Zn含量超过200×10-6,具有矿化显示;全部样品∑REE很低(∑REE=0.82~5.96×10-6),具有明显的Ce负异常(δCe=0.37~0.68),除个别有矿化显示的白云岩样品具有正Eu异常(δEu=1.15~2.40)外,其余样品均具有负Eu异常(δEu=0.56~0.80)。在稀土元素球粒陨石标准化配分模式图上,全部样品均呈现轻稀土富集特征。综合研究,认为白云岩化热液流体具有轻稀土富集及Eu和Ce负异常特征,而氧化还原环境的变化可能是导致本区铅锌矿化的重要因素。  相似文献   

9.
龙门山南段发育一套新元古代火山—沉积地层,其成岩时代及动力学背景一直缺少系统研究,制约了对扬子西缘前寒武纪构造演化的深入理解。本次研究对其下段英安岩和上段流纹岩开展了岩石学、锆石U-Pb年代学和锆石微量元素地球化学研究。结果表明,英安岩和流纹岩的锆石均具有较高的Th, U含量和较大的Th/U比值(0.52~0.90和0.76~1.28),其结晶年龄分别为837±5 Ma和805±4 Ma,表明龙门山南段长英质火山岩形成于新元古代早期。英安岩的锆石具有较低的稀土(ΣREE=160×10-6~389×10-6、ΣLREE=8.3×10-6~18.6×10-6)和Ti含量(2.17×10-6~4.66×10-6)以及较高的Eu/Eu*比值(0.43~0.76)、较低的U/Yb(0.66~1.27),而流纹岩的锆石具有较高稀土(ΣREE=482×10-6~1 345×10-6、ΣLREE=13.7×...  相似文献   

10.
本文总结了河南省栾川—嵩县地区萤石矿床的地质特征,并研究矿床的萤石稀土元素特征,以探讨矿床的成矿物质来源、成矿流体演化以及矿床成因。结果显示,栾川—嵩县地区萤石矿床的萤石样品ΣREE含量范围7.17×10–6~178.02×10–6,平均值67.85×10–6,LREE/HREE值范围0.30~4.31,平均值1.80,δEu范围0.21~1.04,平均值0.64, δCe范围0.11~0.93,平均值0.76。萤石矿床的萤石稀土元素配分曲线形态整体上具有平坦型特点,萤石呈中等Eu和Ce负异常。通过对比萤石矿床的萤石、地层岩石和中生代花岗岩的稀土元素特征及分析各地质体主要成矿元素Ca和F的丰度,认为研究区大规模萤石成矿的物质主要来源于太华群、熊耳群地层,其次是中生代花岗岩体或岩浆期后热液;大气降水的参与以及成矿流体的运移是成矿流体由还原环境向氧化环境逐渐过渡的主要因素。萤石稀土元素La/Ho-Y/Ho关系图表明,萤石成矿在大尺度时间范围内具有同源性、小尺度时间范围内具有同源不同期性的特点。栾川—嵩县地区萤石矿床是由地层岩...  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.
《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   

20.
We have developed a set of four synthetic standards for the rare earth and high field strength elements designed for use in the determination of those elements in silicates. The base material is a glass nominally at the eutectic of the MgO-Al2O3-SiO2 ternary system. The nominal doping level was 2 wt% of the elements as oxides. To avoid problems associated with peak interference, the elements were doped in four separate glasses.  相似文献   

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