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1.
本文通过对内蒙古架子山斑岩型钼(银)矿床7件辉钼矿样品的Re-Os同位素测定与分析,获得了辉钼矿的模式年龄介于143.1±2.1～147.2±2.4 Ma之间,加权平均年龄为145.8±1.4 Ma(MSWD=1.5),对应的等时线年龄为147.4±1.4 Ma(MSWD=1.5),表明架子山钼(银)矿床形成于晚侏罗世,属中国东部燕山期大规模钼成矿期成矿.架子山钼(银)矿床Re含量在37.62×10-6～401.34×10-6之间,平均值为121.28×10-6,表明架子山钼(银)矿床的成矿物质具有壳幔混源特征. 相似文献
2.
甘肃西成矿集区是西秦岭最重要的多金属成矿区之一,以铅锌矿床为主,其次发育有金、铜、钼等矿床(点)。厂坝黑云母二长花岗岩体位于西成矿集区中东部,岩体南缘接触带部位发育石英脉型钼矿,辉钼矿呈中粗粒半自形团块状产于粗粒石英脉内。Re-Os同位素年代学研究表明,其模式年龄范围为207.7±3.0~209.8±2.8Ma,加权平均年龄为208.9±1.1 Ma,等时线年龄为209±15 Ma,指示钼矿化发生于晚三叠世。辉钼矿的铼含量介于18.82×10~(-6)~21.97×10~(-6)之间,平均19.65×10~(-6),表明成矿物质主要为壳幔混合来源,可能以壳源为主。钼矿化与区域岩浆活动以及金、铅锌成矿作用时代相近,是印支期区域构造-岩浆-流体活动的产物。钼矿化年龄的厘定为区内找矿提供了新的思路。 相似文献
3.
安徽省铜陵姚家岭锌金多金属矿是近年来我国新发现的特大型锌金矿床。本文介绍了该矿床的基本地质特征,并对其进行了辉钼矿Re-Os同位素定年。结果表明,姚家岭辉钼矿模式年龄为140.3±2.0~143.0±2.2Ma,加权平均年龄为141.43±0.85Ma,MSWD=0.78,等时线年龄为142.5±1.6Ma,MSWD=1.2,表明姚家岭锌金多金属矿形成于早白垩世晚期,并与铜陵矿集区其他金属矿床成岩成矿年龄一致。样品中Re含量介于0.2421‰~1.346‰,指示成矿物质来源于幔源岩浆。矿床形成于长江中下游燕山期成岩成矿作用的第一期成矿期,处于中国东部区域构造—动力机制转换阶段。 相似文献
4.
河南栾川火神庙钼矿床辉钼矿Re-Os同位素年龄及其地质意义 总被引：1，自引：1，他引：0
火神庙矽卡岩型钼矿床是东秦岭钼矿带栾川矿集区近些年查明的一个中型钼矿床,钼矿体主要赋存于火神庙复式岩体与新元古界蓟县系三川组大理岩接触带的矽卡岩中。为厘定火神庙钼矿床的成矿时代、成矿物质来源及与南泥湖—三道庄、上房沟钼矿床的关系,采用ICP-MS辉钼矿Re-Os同位素定年法对6件辉钼矿样品进行成矿年龄测定,获得的模式年龄为146.1Ma±2.0Ma~148.1Ma±2.1Ma,年龄加权平均值为147.01Ma±0.95Ma,等时线年龄为145.7Ma±3.9Ma,表明火神庙钼矿床形成于晚侏罗世。辉钼矿样品的Re含量为39×10-6~65.4×10-6,显示成矿物质来源于壳幔混源。火神庙钼矿床与南泥湖—三道庄、上房沟钼矿床均为栾川矿集区晚侏罗世第二次岩浆活动的产物,它的发现为在栾川矿集区西部寻找矿产资源提供了依据。 相似文献
5.
鄂东南地区鸡笼山矽卡岩金矿床的辉钼矿Re-Os同位素年龄及其构造意义 总被引：2，自引：0，他引：2
鄂东南地区是我国长江中下游Cu-Au-Fe-Mo成矿带中最重要的组成部分之一,其中鸡笼山金矿是是区内典型的大型矽卡岩金矿床。本文利用Re-Os同位素定年方法对鸡笼山金矿床进行了成矿时代测定,获得了辉钼矿的Re-Os同位素模式年龄范围为147.7±2.4~151.6±4.0Ma,等时线年龄为148.6±1.5Ma,与矿区内花岗闪长斑岩SHRIMP锆石U-Pb年龄151.6±0.7Ma相吻合,也与鄂东南地区其他矿田的成矿时代基本一致。鸡笼山矽卡岩金矿床可能形成于岩石圈伸展构造背景。硫同位素值为-2.5‰~5.5‰,均值为2.84‰,具有明显的塔式效应,反映了成矿物质具有岩浆来源的特征;辉钼矿中Re含量为174.3×10-6~871.4×10-6,平均为476.2×10-6,表明成矿物质来源属于壳幔混源型。 相似文献
6.
内蒙古丰镇市泉子沟斑岩钼矿床成岩成矿年代学及其地质意义 总被引：1，自引：0，他引：1
泉子沟斑岩钼矿床位于内蒙古丰镇市,地处华北克拉通北缘内蒙古台隆凉城断隆内。矿区出露一套燕山期花岗质杂岩体——红娘山杂岩体,主要由中粗粒花岗岩、似斑状花岗岩和石英斑岩组成,钼矿体主要赋存于似斑状花岗岩中。文章在详细的野外地质调查基础上,对泉子沟矿床的成岩成矿时代进行了详细研究,并探讨了地质意义。5件辉钼矿样品的Re-Os模式年龄介于(158.8±2.2)Ma~(161.5±2.2)Ma之间,其加权平均值为(159.8±1.0)Ma(MSWD=0.92),等时线年龄为(161.7±3.1)Ma(MSWD=1.40)。红娘山杂岩体LA-ICP-MS锆石U-Pb年龄分别为:中粗粒花岗岩结晶年龄为(173±1)Ma(MSWD=0.88),似斑状花岗岩侵位年龄为(162±1)Ma(MSWD=0.40),石英斑岩结晶年龄为(160±2)Ma(MSWD=1.90)。辉钼矿Re-Os和锆石U-Pb定年结果表明,泉子沟钼矿床形成于晚侏罗世早期,成矿与似斑状花岗岩关系密切。泉子沟钼矿床的辉钼矿w(Re)介于16.49×10~(-6)~32.87×10~(-6),暗示成矿物质主要来自下地壳。 相似文献
7.
《矿物岩石地球化学通报》2017,(6)
为研究辽宁宽甸地区近年来新发现的东北沟钼矿的成矿时代及其物质来源,对东北沟钼矿床中的5件辉钼矿样品进行了Re-Os同位素地球化学测试和定年。结果表明,辉钼矿的模式年龄为127.1~132.6 Ma,等时线年龄为(128.1±5.1)Ma,与赋矿围岩二长花岗岩的成岩时代(129.4 Ma)一致,由此认为二者均为燕山期构造-岩浆-成矿作用的产物;辉钼矿Re含量为(5.10~23.38)×10~(-6),与内生钼矿床辉钼矿Re含量对比介于壳源-壳幔混合源之间,初步判定东北沟钼矿成矿物质来源介于壳源与壳幔混合源之间,有可能以壳幔混合源为主。结合区域构造演化,认为东北沟钼矿可能是古太平洋板块向欧亚大陆俯冲构造背景下岩浆活动的产物。 相似文献
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《矿物岩石》2017,(2)
哈陇休玛钼(钨)矿床位于东昆仑东段地区,矿床成因为斑岩型,花岗闪长斑岩与成矿关系密切。应用锆石LA-ICP-MS U-Pb法和Re-Os同位素测年法对1件花岗闪长斑岩样品和4件辉钼矿样品进行精确定年。结果表明:成矿花岗闪长斑岩体的形成年龄为(224.68±0.88)Ma(MSWD=0.85);4件辉钼矿样品和1件重复样品的辉钼矿Re-Os等时线年龄为(223.5±1.3)Ma(MSWD=0.66),模式年龄的加权平均值分别为(224.0±1.5)Ma(MSWD=1.8),等时线年龄与模式年龄加权平均值在误差范围内一致。等时线年龄代表了辉钼矿的结晶时间,证实矿区成岩成矿时代晚三叠世,稍晚于东昆仑西段地区钼成矿时代(钼矿主成矿期为中三叠世)。本区辉钼矿w(Re)为4.37×10~(-6)~38.26×10~(-6),平均16.55×10~(-6)与壳幔混源的辉钼矿w(Re)相近(n×10~(-5)),成矿物质来源可能为壳幔混合源,与整个东昆仑造山带晚三叠世强烈壳-幔相互作用大背景相一致。 相似文献
9.
东昆仑热水钼多金属矿床辉钼矿Re Os同位素年龄及地质意义 总被引：2，自引：0，他引：2
热水钼多金属矿床位于青海省东昆仑造山带东段,是近年来新发现的一处斑岩型钼矿床。该矿床钼矿体主要分为四个矿带,矿体呈条带状,脉状等产出,矿石矿物以辉钼矿为主,围岩蚀变较为发育,具有一定分带性,呈面型蚀变,线性排布特征。本文通过Re-Os同位素定年方法对钼矿区6件辉钼矿样品进行了精确年龄测定,其模式年龄介于229.4±3.1~230.6±3.1Ma之间,年龄分布范围较为集中,平均为230.17Ma,等时线年龄为228.6±7.9Ma,MSWD=0.25,模式年龄加权平均值为230.2±2.5Ma,MSWD=0.025,表明成矿作用形成于印支期。6件辉钼矿样品Re含量介于13.02×10~(-6)~17.7×10~(-6),指示成矿物质可能主要来源为壳幔混合。结合已有成矿年龄研究,认为东昆仑造山带印支期成矿作用强烈,主要可分为两期,印支早期与印支晚期,形成一系列矿床,在印支晚期后碰撞阶段与岩浆热液相关的矿床具有较大成矿潜力。 相似文献
10.
皖南宁国竹溪岭钨银矿床是近年来发现的一个与花岗岩类有关的矽卡岩型矿床,准确厘定其成矿年龄及相关侵入岩体的年龄有利于深入认识区域岩浆作用与成矿作用的规律。本文在矿床地质调查的基础上,应用现代同位素定年技术开展地质年代学研究,获得矿床矿石中的辉钼矿Re-Os模式年龄为142.7±2.1 Ma和142.9±2.1 Ma,相关侵入岩体花岗闪长岩、花岗斑岩和花岗闪长斑岩的LA-ICP-MS锆石U-Pb年龄分别为139.8±1.8 Ma、143.3±1.9 Ma、140.2±1.7 Ma,显示矿床的成矿年龄与侵入岩体的成岩年龄基本一致,为燕山晚期早白垩世。矿床矿石中的辉钼矿的Re含量指示成矿物质来源于地壳和地幔的混合;与成矿相关侵入岩的稀土元素和Hf同位素组成特征指示成岩物质也具有壳幔混源特征,显示成矿物质来源与成岩物质来源具有一致性。区域岩浆岩和矿床的对比表明,与之相邻的长江中下游地区、浙西地区和赣东北地区乃至整个华南地区这一时期发生了大规模的岩浆作用和钨锡多金属成矿作用,显示扬子板块在此阶段处于岩浆–成矿大爆发时期,皖南地区的成矿时代对应于华南中生代三次大规模岩浆作用和成矿作用的第二阶段。 相似文献
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S. Viswanathan K. Surya Prakash Rao B. Mahabaleswar 《Journal of the Geological Society of India》2013,82(6):621-627
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.
E. M. Prasolov S. A. Sergeev B. V. Belyatsky E. S. Bogomolov K. A. Gruzdov I. N. Kapitonov R. Sh. Krymsky V. O. Khalenev 《Geochemistry International》2018,56(1):46-64
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
13.
奥地利安东帕有限公司 《岩矿测试》2009,28(3):306-306
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
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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
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《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
19.
Marta L. PATINO-DOUCE Alberto PATINO-DOUCE Mazhar QAYYUM Roger L. NIELSEN 《Geostandards and Geoanalytical Research》1994,18(2):195-198
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-Al2 O3 -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
20.
Alexander E. C. Broberg J. S. Kehren A. R. Graziani M. M. Turri W. L. 《Environmental Geology》1993,22(4):353-361
Bellechester, Minnesota, is a small community of approximately 155 residents located on the county line between Goodhue and Wabasha counties in southeast Minnesota's karst region. Bellechester is served by a 21-year-old wastewater treatment facility (WWTF) consisting of three waste-stabilization ponds. On 28 April 1992 six sinkholes were discovered to have drained cell 2 of the WWTF resulting in the loss of approximately 8.7×106 1 of partially treated effluent and about 600 m3 of soil into previously undetected subsurface voids of unknown dimensions. In the week following the collapse, approximately 200 water wells located within a 5-km radius of the WWTF were sampled in an after-the-fact, emergency sampling program. Twelve samples with elevated fecal coliform levels, 18 samples with nitrate-nitrogen greater than the 10 mg/1 standard, and no samples with elevated chlorides were found. However, the elevated levels could not be unambiguously attributed to the WWTF collapse. This is the third WWTF to fail by sinkhole collapse in southeast Minnesota since 1974. All three collapsed lagoons have been located in similar geomorphic and stratigraphic settings. However, at least two lagoons have collapsed in the adjacent area in northeast Iowa, and these lagoons are located at different stratigraphic positions. Twenty-two WWTFs constructed in southeast Minnesota's karst region in the last 25 years have been identified as subject to potential sinkhole collapse. An unknown but significant number of manure storage lagoons, flood control structures, etc., have also been constructed in the karst region and are at risk. Public agencies are beginning to develop plans to deal with the risk associated with existing and future waste lagoons in this environment. The critical hydrogeologic parameters that can be used to prioritize the risk of collapse at existing facilities include: (1) the lithology of the first bedrock beneath each lagoon, (2) the thickness of surficial materials between the lagoon and the bedrock surface, (3) the presence and construction of liners (seepage rate), and (4) the proximity to existing sinkholes. 相似文献