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1.
江西武山和永平铜矿含矿花岗质岩体锆石SIMS U-Pb年代学 总被引：40，自引：2，他引：38
江西武山和永平铜矿床是长江中下游金属成矿带中的两个重要矿床。对武山铜矿的花岗闪长斑岩和永平铜矿的花岗斑岩中锆石分别进行了离子探针(SIMS)U-Pb定年研究,发现两个矿区的锆石年龄可分作两期,武山铜矿含矿岩体锆石206Pb/238U年龄分别为145±3.9Ma和121±2.5Ma,永平铜矿含矿岩体锆石206Pb/238U年龄分别为160±2.3Ma和135±7.4Ma。这两期不同的年龄可能反映了锆石在岩浆侵位时的结晶年龄和后期热液蚀变作用的年龄。因此确定武山铜矿花岗质岩体的侵位年龄为145Ma,永平铜矿花岗质岩体的侵位年龄为160Ma。该年龄可能也反映了这两个矿床中与燕山期岩浆侵入有关的矽卡岩型矿床和斑岩型矿床的形成时代。 相似文献
2.
红柳沟铜镍矿化基性-超基性岩体位于塔里木板块北缘北山裂谷带,岩体两侧分别为大山头—岗流脑子、方山口—庙庙井—双鹰山2条区域性深大断裂带。岩体侵位于敦煌岩群,铜镍矿化通常赋存于杂岩体中二辉橄榄岩、橄榄二辉辉长岩、橄榄苏长辉长岩等基性程度较高的岩石内。通过SHRIMP锆石U-Pb定年,首次获得红柳沟矿化橄榄角闪辉长苏长岩锆石的U-Pb年龄为(396.7±3.8)Ma,表明该含矿杂岩体的侵位及矿化作用均发生于中泥盆世,结合区内已知黑山和怪石山等铜镍含矿岩体年龄,从而揭示出甘肃北山地区在中—晚泥盆世一直处于陆缘裂谷拉张环境。 相似文献
3.
鄂东鸡冠嘴矿区成矿岩体锆石SHRIMP U-Pb定年及其意义 总被引：5，自引：0，他引：5
鄂东鸡冠嘴铜金(铁)矿床位于阳新岩体西北端,与铜绿山铜金矿床毗邻。矿区成矿岩体主要岩性为石英正长闪长玢岩、石英闪长岩、闪长岩和安山玢岩。其中石英正长闪长玢岩与成矿关系密切。在前人矿床地质特征研究基础上,笔者对成矿岩体进行了锆石SHRIMP U-Pb定年,获得石英正长闪长玢岩和闪长岩的年龄为146±2Ma(95%可信度,MSWD=1.3)和132±4Ma(95%可信度,MSWD=3)。测定结果表明,区内石英正长闪长玢岩和闪长岩分属燕山早期和燕山晚期岩浆活动的产物。鉴于矿体在空间上主要赋存于岩体内外接触带及层间破碎带中,推测成矿作用应略晚于石英正长闪长玢岩(146±2Ma)而早于闪长岩侵位的时间(132±4Ma),这与前人获得长江中下游铜铁金成矿带代表性矿床的辉钼矿Re-Os模式年龄分布在134.7～143Ma的研究结果一致。 相似文献
4.
山东邹平火山岩盆地铜多金属矿SHRIMP
锆石U-Pb和辉钼矿Re-Os年龄 总被引：2，自引：0，他引：2
邹平火山岩盆地是山东省重要的铜多金属矿区之一,区内含有1套多旋回多期次的中生代火山-侵入杂岩,已发现的铜矿床、矿化点均与晚期侵入杂岩体及次火山岩有关。为了查明矿区的成岩成矿作用时代,采用SHRIMP同位素测定技术,对区内与铜多金属矿化有关的侵入岩中的锆石进行了U-Th-Pb同位素测定,获得王家庄铜矿床的赋矿围岩——石英二长闪长岩的侵位年龄为（128.8±0.8）Ma,盆地中部裂隙充填交代型铜金矿床的赋矿围岩环状二长岩岩墙的侵位年龄为（122.9±0.5）Ma;对王家庄铜矿中的5件辉钼矿样品进行了Re-Os同位素分析,获得的等时线年龄为（126.7±4）Ma及模式年龄加权平均值（128.2±0.8）Ma,代表了辉钼矿在流体中沉淀的时间。所获年龄数据准确地厘定了区内晚期岩浆活动及其矿化时限,表明王家庄杂岩体的侵位时间早于环状二长岩岩墙,其多金属矿化时间与成岩时间接近,岩体与矿化关系密切;而裂隙充填交代型铜矿的形成时间晚于环状二长岩岩墙,具有明显的构造控矿特征。所获得的年龄数据对于进一步研究区域成矿规律和指导找矿具有重要的意义。 相似文献
5.
黑龙江多宝山斑岩Cu-Mo矿床成岩成矿时代研究 总被引：12，自引：4，他引：8
多宝山斑岩型铜(钼)矿床是中国东北地区重要的斑岩型铜(钼)矿床,文章对矿区主要成矿岩体及辉钼矿样品进行了系统的成岩成矿年代学研究。对成矿岩体采用高精度LA-ICP-MS锆石U-Pb测年,获得成矿母岩花岗闪长斑岩的锆石U-Pb年龄为(474.8±4.7) Ma,矿体寄主岩石花岗闪长岩的锆石U-Pb年龄为(478.1±4.1) Ma,以及矿体外围黑云母花岗闪长岩的锆石U-Pb年龄为(483.9±4.5) Ma;矿体辉钼矿的Re-Os同位素模式年龄加权平均值为(475.1±5.1) Ma。测年结果显示,多宝山斑岩铜(钼)矿床形成于早奥陶世。结合含矿地层、矿区岩石组合特征,以及前人研究的岩石地球化学特征,推测多宝山矿床形成于早奥陶世与板块俯冲有关的岛弧环境,说明在区域上寻找类似多宝山的斑岩铜矿应沿早奥陶世多宝山-伊尔斯岩浆岛弧带开展。 相似文献
6.
甘肃北山地区黑山铜镍矿化基性—超基性杂岩体
SHRIMP锆石U-Pb定年及其地质意义 总被引：2，自引：0，他引：2
黑山铜镍矿床位于塔里木板块东北部的北山裂谷带内,庙庙井－双鹰山深大断裂南侧,含矿基性—超基性复式杂岩体侵位于青白口系大豁落山组和寒武系双鹰山组中。矿化主要赋存于杂岩体内的橄榄岩和角闪辉长岩内。采用锆石离子探针微区原位（SHRIMP）法获得矿化角闪辉长岩中锆石的U-Pb年龄为374.6Ma±5.2Ma,表明该含矿杂岩体的侵位及矿化作用均发生于晚泥盆世。这一年龄数据的获得不仅对重新认识北山地区的地质构造演化具有重要意义,而且为北山地区开展铜镍矿找矿提出了新方向。 相似文献
7.
藏东玉龙超大型斑岩铜矿床成岩成矿系统时间跨度分析 总被引：12，自引：5，他引：7
藏东玉龙超大型斑岩铜矿床是目前西藏发现的最大斑岩铜矿床,含铜岩体主要由早期石英二长斑岩及晚期正长花岗斑岩组成。本文用LA-ICP-MS法测定早期石英二长斑岩及晚期正长花岗斑岩锆石U-Pb年龄及Ar-Ar法测定钾质蚀变带黑云母的Ar-Ar年龄,发现玉龙含矿斑岩体早期石英二长斑岩锆石LA-ICP-MS U-Pb年龄(41.3±0.3Ma, MSWD=0.92)与晚期正长花岗斑岩锆石LA-ICP-MS U-Pb年龄(41.3±0.2Ma, MSWD=1.24)基本相同,也和黑云母Ar-Ar坪年龄(41.7±0.8Ma)及等时线年龄(41.3±0.8Ma)在误差范围内一致。玉龙斑岩铜矿早期及晚期岩体锆石U-Pb年龄一致表明含矿岩体在地质上的早期及晚期主要是岩浆在较短时间内脉动侵入所致。玉龙含矿岩体锆石U-Pb年龄(封闭温度约800℃)、39Ar-40Ar 年龄(封闭温度约300℃)及前人获得的Re-Os年龄40.1±1.8Ma(封闭温度约500℃)在误差范围内基本一致,表明含矿岩体岩体快速冷却,玉龙超大型斑岩铜矿床成岩成矿系统时间跨度小于1Ma。 相似文献
8.
铜陵狮子山地区中酸性侵入岩锆石SHRIMP U-Pb定年及岩浆作用的深部过程 总被引：24，自引：11，他引：13
铜陵狮子山地区中酸性侵入岩锆石SHRIMP U-Pb定年结果表明,白茫山辉石二长闪长岩、鸡冠山和大团山石英二长闪长岩以及胡村花岗闪长岩的年龄分别为:138.21 ±0.82Ma、139.9 ±1.1Ma、139.3 ±1.2Ma和140.9 ±1.2Ma.岩浆侵位顺序为花岗闪长岩→石英二长闪长岩→辉石二长闪长岩.根据锆石SHRIMP U-Pb年龄变化范围,推测该区岩浆活动持续的时间约为15Ma,且岩浆属脉动式多次侵位,后期岩浆侵位的热使早期岩体中已结晶的锆石发生熔解、重结晶,形成新的锆石.地下深部岩浆活动频繁,形成了多级岩浆房,使得本区的莫霍面界线不明显. 相似文献
9.
柴达木盆地西北缘新发现的牛鼻子梁铜镍矿床位于阿尔金南缘断裂和柴北缘断裂交汇部位。矿区内包含3个镁铁-超镁铁岩体,其中Ⅱ、Ⅲ号岩体中可见铜、镍硫化物矿化,区内岩体岩相分带明显,由南往北可分为橄榄岩相、辉石岩相和辉长岩相。橄榄岩相岩石包含角闪二辉橄榄岩、角闪橄榄岩、二辉橄榄岩、斜长二辉橄榄岩,辉石岩相岩石包含橄榄二辉岩、二辉岩。镍、铜矿化与橄榄岩相岩石关系密切。本文利用LA-ICP-MS锆石U-Pb同位素定年法测得Ⅰ号岩体闪长岩形成年龄为(388.0±2.8)Ma,Ⅱ号矿化岩体二辉橄榄岩形成年龄为(402.2±2.8)Ma,Ⅲ号矿化岩体斜长二辉橄榄岩形成年龄为(402.8±2.6)Ma。属早泥盆世,表明牛鼻子梁岩体形成于造山后陆内拉张环境,为晚古生代早期幔源岩浆活动的产物。牛鼻子梁铜镍矿床是中国除了夏日哈木矿床外又一形成于早泥盆世新的铜镍矿化类型,具有较好的镍铜硫化物矿床成矿潜力。 相似文献
10.
南祁连乙什春基性-超基性岩体LA-ICP-MS锆石 U-Pb年龄及其地质意义 总被引：2，自引：0，他引：2
研究区位于中祁连地块南缘, 青海湖南- 古雷深大断裂南侧,是祁连成矿带铜镍矿找矿最有利地区。铜镍矿矿体产于
同源同期侵入的基性- 超基性岩体内, 铜镍矿化无论在时间上和空间上都与岩体的侵位密切相关。本次研究对乙什春基性-
超基性岩体中的锆石进行了阴极发光(CL) 成像观察, 结合Th/U比值特征,显示其为岩浆成因;并应用LA-ICP-MS 对锆石微
区U-Pb 年龄进行了测定,获得乙什春含矿岩体中锆石加权平均年龄为（455.1±1.7） Ma,表明其含矿岩体的侵位及矿化作
用发生于晚奥陶世,成岩成矿的动力学背景为陆缘裂谷构造环境。 相似文献
同源同期侵入的基性- 超基性岩体内, 铜镍矿化无论在时间上和空间上都与岩体的侵位密切相关。本次研究对乙什春基性-
超基性岩体中的锆石进行了阴极发光(CL) 成像观察, 结合Th/U比值特征,显示其为岩浆成因;并应用LA-ICP-MS 对锆石微
区U-Pb 年龄进行了测定,获得乙什春含矿岩体中锆石加权平均年龄为（455.1±1.7） Ma,表明其含矿岩体的侵位及矿化作
用发生于晚奥陶世,成岩成矿的动力学背景为陆缘裂谷构造环境。 相似文献
11.
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
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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
14.
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
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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
17.
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
18.
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
19.
Mercury,arsenic, antimony,and selenium contents of sediment from the Kuskokwim River,Bethel, Alaska,USA 总被引：1，自引：0，他引：1
The Kuskokwim River at Bethel, Alaska, drains a major mercury-antimony metallogenic province in its upper reaches and tributaries. Bethel (population 4000) is situated on the Kuskokwim floodplain and also draws its water supply from wells located in river-deposited sediment. A boring through overbank and floodplain sediment has provided material to establish a baseline datum for sediment-hosted heavy metals. Mercury (total), arsenic, antimony, and selenium contents were determined; aluminum was also determined and used as normalizing factor. The contents of the heavy metals were relatively constant with depth and do not reflect any potential enrichment from upstream contaminant sources. 相似文献
20.
滇东南锡、银、铅、锌多金属矿床主要分布在个旧、白牛厂、都龙3个矿区,而滇东南较大的3个花岗岩体又分别出露在3个矿区或附近.花岗岩体均形成于燕山晚期,岩石化学、矿物成分相似,富含锡、银、铅、锌、钨、铜等成矿元素.矿床主金属元素组合与岩体之间的距离由远而近出现由锡、钨、(铍、铌、钽)→锡、钨、(铁)、铜、铟→锡、铅、锌、银、铟、(锑)有规律的变化.花岗岩浆是成矿物质来源和成矿热源.岩浆侵入初期使上覆地层隆起产生背斜(凹陷部位成向斜);同时使地层产生一系列裂隙、压性断层或层间断裂;岩浆侵入晚期,这些断层再次活动,表现为张性,岩浆产生的含矿热液沿由其活动所造成的断裂迁移、充填、交代、沉淀而形成矿床. 相似文献