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1.
湖南邓阜仙印支晚期二云母花岗岩年代学、地球化学特征及其意义 总被引：8，自引：5，他引：3
邓阜仙花岗岩体位于湖南省东部,是印支期-燕山期多期次多阶段侵入的复式岩体。本文对邓阜仙岩体中部的两件二云母花岗岩样品进行了锆石LA-ICP-MS U-Pb测年,得到的锆石U-Pb年龄为222.9±1.6Ma和224.3±2.4Ma,首次证实了邓阜仙岩体存在有印支晚期二云母花岗岩。印支晚期二云母花岗岩具有高硅、高碱、强过铝质的特征,富集Cs、Rb、U、Pb而亏损Ba、Sr、Ti等元素,与华南己发现的其他印支期强过铝质花岗岩类似。花岗岩较高的（87Sr/86Sr）i值（0.721463~0.728115）、较低的εNd（t）值（-11.68~-11.33）以及1.92~1.95Ga的Nd模式年龄说明其主要起源于区内古元古代地壳的部分熔融。邓阜仙印支晚期二云母花岗岩与华南印支期强过铝质花岗岩的成岩时间一致,根据区域地质特征及花岗岩地球化学特征,认为其形成于后造山伸展的构造环境。邓阜仙钨矿与区内燕山期花岗岩有密切的成因联系。印支晚期二云母花岗岩具有较高的钨含量,属于富钨岩体,可能为燕山期的钨成矿作用提供了物质基础。 相似文献
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江西省武功山地区浒坑钨矿床的Re-Os年龄及其地质意义 总被引：2，自引：0，他引：2
浒坑钨矿床是位于江西省中部武功山成矿带的大型石英脉型黑钨矿床。为了确定该矿床的成矿时代,笔者选取了浒坑含钨石英脉中与黑钨矿共生的辉钼矿进行了高精度Re-Os同位素定年,并获得5个辉钼矿样品的Re-Os等时线年龄和模式加权平均年龄分别为150.2±2.2Ma和149.82±0.92Ma。测年数据表明浒坑钨矿床的成矿时代为150Ma左右,是华南地区中生代大规模成岩成矿作用高峰期的产物。辉钼矿含铼较低,表明成矿物质可能来自壳源,与形成浒坑花岗岩体的燕山期重熔S型花岗岩岩浆活动有关。该矿床形成于燕山期岩石圈伸展减薄环境。 相似文献
3.
内蒙碾子沟钼矿床辉钼矿Re-Os同位素年龄及其地质意义 总被引：21，自引：4，他引：17
内蒙古碾子沟石英脉型钼矿床是一新发现的钼矿床,通过对主要钼矿体6件辉钼矿样品的Re-Os同位素分析,获得了150.2±2.2~154.4±2.2Ma之间、平均152.4±1.3Ma（2σ误差,MSWD=1.6）的同位素模式年龄,及一个相关性很好的等时线年龄154.3±3.6Ma（2σ误差,MSWD=1.9）,表明碾子沟钼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,是中国东部中生代构造体制大转折背景下的产物。碾子沟钼矿床辉钼矿的铼含量介于12.6×10-6~37.0×10-6,平均24.9×10-6,通过与其它钼矿床对比,初步认为碾子沟钼矿床成矿物质具有壳幔混源、偏壳源特征。 相似文献
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东秦岭南泥湖钼（钨）矿田Re—Os同位素年龄及其地质意义 总被引：53，自引：2，他引：53
位于华北克拉通南缘东秦岭钼矿带的南泥湖为一超大型夕卡岩斑岩型钼(钨)矿田,本研究采用电感耦合等离子体质谱仪法对南泥湖钼矿田三个矿床6件辉钼矿进行了Re-Os同位素年龄测定,获得南泥湖矿床的辉钼矿Re-Os模式年龄为141.8±2.1 Ma;三道庄矿床的辉钼矿Re-Os模式年龄为144.5±2.2～145.0±2.2Ma,平均为145.0±2.2 Ma;上房沟矿床的辉钼矿Re-Os模式年龄为143.8士2.1～145.8±2.1 Ma,平均为144.8±2.1 Ma;6件样品的等时线年龄为141.5±7.8 Ma(2σ),准确厘定了成矿时间.Re-Os同位素还表明:南泥湖钼矿的成矿物质来源以下地壳成分为主,但混有少量地幔组分.南泥湖钼矿是在中国东部中生代构造体制大转换中形成,属于中国东部中生代大规模成矿作用的一部分. 相似文献
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江西省武功山地区浒坑钨矿床辉钼矿Re-Os年龄及其地质意义 总被引：7，自引：0，他引：7
浒坑钨矿床是位于江西省中部武功山成矿带的大型石英脉型黑钨矿床。为了确定该矿床的成矿时代,笔者选取了浒坑含钨石英脉中与黑钨矿共生的辉钼矿进行了高精度Re-Os同位素定年,并获得5个辉钼矿样品的Re-Os等时线年龄和模式加权平均年龄分别为150.2±2.2Ma和149.82±0.92Ma。测年数据表明浒坑钨矿床的成矿时代为150Ma左右,是华南地区中生代大规模成岩成矿作用高峰期的产物。辉钼矿含铼较低,表明成矿物质可能为地壳来源,与形成浒坑花岗岩体的燕山期重熔S型花岗岩岩浆活动有关。该矿床形成于燕山期岩石圈伸展减薄环境。 相似文献
6.
江西省都昌县阳储岭钨钼矿床位于江南造山带东段,为准确厘定阳储岭钨钼矿床的成岩成矿时代,本次在详实的野外地质调查基础上,对阳储岭成矿花岗闪长斑进行锆石U-Pb定年工作,同时开展辉钼矿Re-Os同位素定年研究。LA-ICP-MS锆石U-Pb年龄为（145.08±0.35）Ma（MSWD=0.51,n=7）;辉钼矿Re-Os模式年龄为（143.3±2.0）Ma~（145.5±2.2）Ma,等时线年龄为（145.4±1.0）Ma。阳储岭成矿花岗闪长斑岩锆石U-Pb年龄与辉钼矿Re-Os等时线年龄基本一致,表明阳储岭钨钼矿床成岩成矿时代约为145 Ma。辉钼矿中Re含量为16.62×10-6~87.76×10-6,平均值为44.68×10-6,与壳幔混源岩浆热液矿床中Re的含量相似,指示阳储岭钨钼矿床成矿物质来源于壳幔混源。 相似文献
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江西岿美山钨矿矿床的成矿年龄及地质特征 总被引：1，自引：0，他引：1
江西省定南县岿美山钨矿区位于南岭东西向构造带东段与武夷山北东-北北东向构造带南段的复合部位,是赣南地区以石英脉型黑钨矿和矽卡岩型白钨矿共生为特征的钨矿床,其是否为南岭地区燕山期的成矿作用,一直没有精确的年代学研究成果。本文采用锆石SHRIMP U-Pb定年和辉钼矿Re-Os同位素定年技术,对岩体年龄和成矿年龄进行了精细的测定,获得成矿黑云母花岗岩体的锆石SHRIMP U-Pb年龄为（157.7±2.7） Ma（n=11,MSWD=1.9）,黑钨矿石英脉的辉钼矿Re-Os等时线年龄为（153.7±1.5） Ma（n=5,MSWD=0.16）,显示岿美山区是华南地区中生代钨矿大规模成岩成矿作用的产物之一。根据“五层楼+地下室”的找矿模型,并结合矿区的最新找矿线索,研究认为在矿区深部岩体的内外接触带具有存在新矿体的可能性,该区深部具有较大的找矿潜力,同时探索性地提出赣南地区石英脉型钨矿深边部存在矽卡岩型钨矿化的可能,对区域钨矿的深边部找矿工作具有指导意义。 相似文献
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内蒙古查木罕钨钼多金属矿床辉钼矿Re-Os同位素年龄及其地质意义 总被引：3，自引：0，他引：3
内蒙古克什克腾旗查木罕钨钼矿床是近年新发现的矿床。本文通过5件辉钼矿样品的Re-Os同位素测定与分析,获得模式年龄137.8～139.3Ma,加权平均值为138.8±2.8Ma,对应的等时线年龄为139.3±1.5Ma,表明查木罕钨钼矿床形成于早白垩世,与中国东部燕山期大规模钨钼成矿期一致。查木罕钨钼矿床辉钼矿的铼含量介于0.127～2.317μg/g之间,平均0.875μg/g,表明查木罕矿床成矿物质主要来源于上地壳。结合区域上已有研究成果,早白垩世是西拉木伦钼成矿带一期重要的成矿作用,并与中国东部大规模成矿时限相一致,该期成矿作用发生于中国东部岩石圈减薄构造背景。 相似文献
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霍吉河钼矿是小兴安岭地区于近年发现的大型斑岩型钼矿床。本文在对矿化特征分析的基础上,采用LA-ICP-MS锆石U-Pb技术对霍吉河成矿花岗质杂岩测年,获得中细粒花岗闪长岩和斑状花岗岩成岩年龄分别为181.0±1.9 Ma(n=15, MSWD=4.7) 和193.6±1.4 Ma(n=25, MSWD=2.3)。通过辉钼矿Re-Os同位素分析,获得等值线年龄176.3±5.1 Ma(n=5, MSWD=1.3)和加权平均年龄为181.2±1.8 Ma (n=5, MSWD=1.3)。两种方法获得的年龄大致相近,表明成岩与成矿于同一系统形成,成岩大致始于193.6±1.4 Ma,成矿于岩浆期后181.2±1.8 Ma。霍吉河钼矿成岩成矿年龄与乌奴格吐山铜钼矿、兰家沟钼矿和杨家杖子钼矿等矿床辉钼矿Re-Os同位素年龄相近,表明中国东北地区广泛存在早侏罗世岩浆成矿作用。微量元素和同位素显示,霍吉河花岗闪长岩和斑状花岗岩属A型花岗岩,形成于地壳挤压向拉伸转换的构造环境,成矿物质主要来自岩浆。 相似文献
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湘西大溶溪钨矿床中辉钼矿Re-Os同位素定年及其地质意义 总被引：9，自引：2，他引：7
湘西大溶溪钨矿床,为雪峰隆起区内的一个中型白钨矿矿床。文章对该矿床中穿插钨矿体的含辉钼矿石英脉进行了Re-Os同位素年代学研究。分析结果显示,该矿中辉钼矿的Re-Os同位素模式年龄为217.0~221.1 Ma,平均为（219.0±1.2） Ma,其对应的等时线年龄为（223.3±3.9） Ma,揭示其形成于晚三叠世。这些年龄数据与矿区内大神山花岗岩的侵位时间〔（224.3±1.0） Ma〕基本吻合,表明该区含辉钼矿石英脉的形成与花岗岩的侵位具有密切的时、空联系。考虑到该区钨矿体的形成时间介于花岗岩和含辉钼矿石英脉之间,因此,推断大溶溪钨矿床形成于223 Ma左右。该研究成果,不仅为湘西雪峰隆起区存在多期次的钨成矿事件提供了可靠证据,同时又进一步证实了华南地区确实存在一次区域性的与印支期花岗岩有关的成矿作用。 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
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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
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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
15.
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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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