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1.
《地质学报》2010,(5)
王坪石岩体具有超酸性(SiO2=73%～76%)、SiO2过饱和(大量石英)、偏铝质到弱过铝质(Al2O3=12.48%～14.23%)和碱性(Na2O+K2O=7.83%～9.41%)的特征。总稀土较低(ΣREE=(54.41～140.21)×10-6),稀土配分型式为左陡右缓的轻稀土元素富集、重稀土元素亏损型。微量元素富集K、Pb等大离子亲石元素以及Rb、Th、U等强不相容元素,相对亏损Ba等大离子亲石元素和Nb、Ta、Ti、La、Ce等高场强元素和P元素。Sr-Nd-Pb同位素地球化学研究表明,该岩体的(87Sr/86Sr)i较低(0.70498～0.70503),εNd(t)为负值(-10.9‰～-12.1‰),以上特征结合岩浆混合的证据表明,该岩体的物质来源主要为下地壳古老变质岩(变质杂砂岩),但受到地幔端员的混染作用。 相似文献
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在区域地质调查及综合研究的基础上,通过详细的岩石学、接触关系、同位素年龄及地球化学特征研究,对位于天水南部地区的晚加里东期百花岩体、熊山沟岩体,早华力西期党川岩体、火炎山岩体的地球化学特征及形成的构造环境进行了讨论.百花岩体岩石化学低钾(K2O/Na2O=0.13～0.91)、低铝(A/CNK=0.74～0.78),微量元素相对富集Cr、Ni、Y、Rb、Sr,贫Nb、Zr,稀土元素丰度较低(∑REE=107.71 × 10-6～191.13×10-6);熊山沟岩体早期岩石化学成分低钾(K2O/Na2O:0.33～0.42),晚期岩石相对富集钾(K2O/Na2O=1.01～1.43),微量元素富集Th、Hf、Nb、Zr等元素.晚加里东期岩体的共同特点是岩石属拉斑-钙碱性系列,稀土元素以富集轻稀土元素、无铕负异常或铕负异常不明显为主要特征,氧同位素值较低(δ18O: 3.32‰),岩石具Ⅰ型花岗岩的特征.熊山沟岩体物质来源于下地壳,百花岩体形成于岛弧构造环境.党川岩体富集SiO2(SiO2=72.29%～73.40%)、K2O(K2O/Na2O=0.86～2.01)、Al2O3(A/CNK=1.05～1.20);火炎山岩体岩石总体SiO2含量较低(平均69.70%),但K2O(K2O/Na2O=1.14～1.88)、Fe2O3 FeO、MgO较高.早华力西期岩体的共同特征是岩石具钾玄质系列岩石地球化学特征,为过铝质岩石(A/CNK>1.0),相对富集大离子亲石元素Ba、zr、Rb、Sm、Ta及Rb、Ba、Th、Nb等,稀土元素丰度较高,轻稀土元素富集,铕亏损强烈,铕负异常明显,δEu值较低(δ Eu=0.36～0.61),(87Sr/86Sr)0大于0.7070,氧同位素δ18O较高(δ18O= 8.89‰～ 11.08‰),物源为上地壳物质,属壳源花岗岩类,岩石具S型花岗岩的特征,形成于后碰撞构造环境或后造山构造环境. 相似文献
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龙王(石童)A型花岗岩地球化学特征及其地球动力学意义 总被引：11，自引：0，他引：11
龙王花岗岩岩体产于华北克拉通南缘,岩石类型主要为黑云母钾长花岗岩,局部见有霓辉石花岗岩。岩体高硅(SiO2=72.17%～76.82%)、富碱(K2O+Na2O=8.28%～10.22%,K2O/Na2O>1),碱性指数AI(agpaitic index)=0.84～0.95,分异指数DI=95～97,铝指数ASI(aluminium saturation index)=0.96～1.13。含铁指数高(FeO/(FeO+Mg)=0.90～0.99),岩石为准铝质至弱过铝质、碱性—碱钙性、铁质A型花岗岩。岩石富集大离子亲石元素,稀土元素含量很高(854～1572μg/g);高场强元素(Nb、Ta、Zr、Hf)的富集程度明显低于大离子亲石元素,因此在微量元素蛛网图上呈相对亏损特征;岩石显著亏损Ba、Sr、Ti、Pb;εNd(t)=-4.5～-7.2,Nd模式年龄为2.3～2.5Ga。εHf(t)=-1.11～-5.26,模式年龄tHf1=2.1～2.3Ga,tHf2=2.4～2.6Ga。黑云母钾长花岗岩中的锆石主要为无色透明柱状晶体,CL图像多数显示清晰的岩浆成因的韵律环带结构,锆石LA-ICPMSU-Pb年龄为... 相似文献
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阿拉善地块北缘雅干花岗岩体地球化学、地质年代学及其对区域构造演化制约 总被引：4，自引：1，他引：3
位于阿拉善北部中蒙边境地区的雅干花岗岩体以二长花岗岩为主,岩体的锆石离子探针U-Pb年龄为283.2±2.2Ma (n=14,MSWD=0.016).该花岗岩体具有相对较低的SiO2含量(66.96％～70.71％),和较高的A12O3(15.05％～16.05％)和(Na2O+ K2O)含量(7.24％～9.19％),且岩体钠含量稍高(Na2O/K2O＞1).雅干花岗岩体总体上表现为高钾钙碱性及偏铝质-过铝质的特征.岩体稀土元素总合量为101.9×10-6～133.1 ×1O-6,在稀土元素配分模式图中,岩体表现为轻-重稀土元素中等程度-强烈分异,同时具有明显的负Eu异常(δEu =0.59 ～0.77);在微量元素原始地幔标准化蛛网图中,岩体表现为亏损Nb、Ta、P、Ti,富集Ba、Rb、Cs、Th、K等大离子亲石元素;岩体同位素特征则表现为具有高的(87 Sr/86 Sr)i值(0.707654 ～0.710235)以及负εNd(t)值.根据雅干花岗岩体的形成时代、地球化学特征以及相关的沉积建造特征,可推断该岩体形成于后碰撞环境,表明古亚洲洋在阿拉善地块北缘北部地区的分支于早二叠世(283.2 ±2.2Ma)之前已经闭合. 相似文献
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通过对陕西金堆城钼矿区花岗斑岩体和八里坡斑岩体进行地球化学测试,测得金堆城斑岩体的SiO2含量为72.89%～74.06%,MgO为0.07%～0.3%,稀土总量为43.29×10-6～93.94×10-6,稀土元素配分曲线呈右倾型,具有明显的铕负异常和弱的负铈异常(δEu为0.43～0.78,δCe为0.74～0.86),富集大离子亲石元素K、Rb、U、Th和Sr等元素,亏损Ba、P和Ti等元素。八里坡斑岩体的SiO2含量为69.87%～70.80%,Al2O3 14.93%～15.46%,MgO 0.28%～0.48%,Sr/Y比值大于60,稀土总量为125.23×10-6～139.63×10-6,铕为无异常或微弱的正异常(δEu为0.98～1.04),铈为微弱的负异常(δCe为0.92～0.96),富集Ba、U、K等大离子亲石元素,而亏损P、Ta和Ti等元素。金堆城斑岩体和八里坡斑岩体的岩石类型为I型花岗岩,Pb同位素显示金堆城斑岩体的Pb主要来自下地壳,但有地幔物质的加入,八里坡斑岩体的Pb主要来自下地壳。金堆城斑岩体的ε(Nd,t)值为较低负值(-13.8～-15.2),但ε(Sr,t)变化较大,为-46.4～13.6,八里坡斑岩体具有负低ε(Nd,t)值(-20.4)和正高ε(Sr,t)值(64.5～65.2)。金堆城花岗斑岩和八里坡花岗斑岩的Sr、Nd、Pb同位素与华北地块相似,这两个岩体的源区为华北地块组成部分。 相似文献
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《矿物学报》2013,(4)
湖北省蕲春县烈马咀花岗岩主要为黑云母二长花岗岩,由黑云母、钾长石、斜长石和石英等矿物组成,属于梅川杂岩体主岩体乱泥滩单元的组成部分。LA-ICP-MS锆石U-Pb定年结果显示,其U-Pb谐和年龄为123±0.85 Ma(N=15,MSWD=0.21),206Pb/238U表面年龄加权平均值为123±1 Ma(N=15,MSWD=0.21),略晚于乱泥滩主岩体侵位年龄(131 Ma)和大别山地区晚中生代岩浆活动峰期年龄(130 Ma)。烈马咀花岗岩主-微量元素分析显示,主要元素以高SiO2(74.76%77.64%)、富碱(K2O+Na2O 7.18%77.64%)、富碱(K2O+Na2O 7.18%7.96%)和过铝质(Al2O312.73%7.96%)和过铝质(Al2O312.73%14.06%)为特征;微量元素以富集大离子亲石元素(如Rb和Pb等)和亏损高场强元素(如Nb、Zr、P和Ti等)为特征;稀土元素具有轻稀土富集和Eu负异常(δEu=0.4114.06%)为特征;微量元素以富集大离子亲石元素(如Rb和Pb等)和亏损高场强元素(如Nb、Zr、P和Ti等)为特征;稀土元素具有轻稀土富集和Eu负异常(δEu=0.410.65)特征。烈马咀花岗岩成岩年龄和岩石地球化学特征显示其成因与大别山造山带内晚中生代花岗岩类似,均来自古老下地壳物质的部分熔融,形成于晚中生代整个中国东部岩石圈伸展减薄的构造背景下。 相似文献
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国庆钾长花岗岩岩体出露于蒙古自治区额济纳旗西南部的盘陀山一带,北邻牛圈子-洗肠井缝合带,LA-ICP-MS测得该岩体的U-Pb年龄为439.1±8Ma。岩体SiO2含量73.31%～74.36%,A/CNK>1.1,K2O/Na2O=1.25～1.40,里特曼指数介于2.06～2.22之间,属于高钾钙碱性、过铝质花岗岩系列,岩体富集大离子亲石元素,亏损高场强元素。稀土和微量元素分析显示钾长花岗岩总体轻稀土元素富集,轻、重稀土元素分馏较低,具有较明显Eu负异常(δEu=0.65～0.77),具K、Rb、Ba、Th等元素富集,Nb、Ce、Zr、Hf、Sm、Y、Yb等元素亏损的特征。综合分析表明,国庆钾长花岗岩为壳源S型同碰撞花岗岩;结合区域构造演化历史,认为国庆钾长花岗岩为古老地壳物质重熔形成,是早志留世月牙山-洗肠井古洋盆闭合同碰撞阶段的产物。同时对该区志留—泥盆纪碰撞伸展环境下成矿前景初步分析,为矿床研究和区域矿产预测工作提供参考。 相似文献
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对苏尼特左旗地区阿木乌岩体进行LA-ICP-MS锆石U-Pb测年、主量元素、稀土元素和微量元素测试分析。结果表明,岩体成岩年龄为235.1±3.2 Ma,属中三叠世。岩体具有高SiO2、富K2O、低CaO、低TiO2的特征。强烈亏损Sr、Ba、Ti、P等元素,富集K、Rb、Th等亲石元素,具有右倾"海鸥型"球粒陨石标准化稀土配分型式及强烈的负铕异常等特点。A/CNK=0.77～1.19,A/NK=1.26～1.64,表明阿木乌岩体具有偏铝质A型花岗岩的特征。具有较高的Y/Nb值(2.31～3.001.2),显示出A2型花岗岩的特征,说明岩体形成于造山后的伸展环境。 相似文献
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内蒙古敖汉旗克力代岩体锆石U-Pb年代及地球化学 总被引：1，自引：0，他引：1
通过LA-ICP-MS锆石U-Pb测年对内蒙古敖汉旗克力代岩体进行研究。结果表明,岩浆锆石的加权平均年龄为263±1 Ma,表明其结晶年龄为中二叠世。岩石地球化学分析表明,岩体具有高Si(SiO2=69.94%～72.56%),富ALK(Na2O+K2O=8.04%～9.23%),贫Fe(FeOT=1.50%～1.82%)、Mg(MgO=0.65%～0.86%)、Ti(TiO2=0.32%～0.35%)的特点;A/CNK值为0.87～0.93,为准铝质;A/NKC1.1,显示出I型花岗岩特征。固结指数(SI)为6.06～7.36,分异指数(DI)为88.82～91.82,说明岩体经历了较强的分异演化作用。稀土元素总量较低(ΣREE=91.76×10-6～143.16×10-6),轻稀土明显富集,重稀土相对亏损,LREE/HREE值平均为9.14,(La/Yb)N平均值为8.36,δEu平均值为0.58,为Eu亏损型。大离子亲石元素(LILE)Rb、K较富集,强烈亏损高场强元素(HFSE)Nb、Ti、Ta。因此,判定克力代岩体为高钾钙碱性I型花岗岩。结合测年结果和地球化学特征,判定该岩体为晚海西期华北板块和西伯利亚板块碰撞作用形成的同碰撞型花岗岩。 相似文献
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琼北地区花岗岩出露较少,多零星分布在翁田镇至大致坡镇一带。本次研究选取该区域的翁田岩体为研究对象,通过LA-ICP-MS锆石U-Pb定年,限定该岩体形成时代为245.1±2.4 Ma,属于中三叠世。翁田岩体主要岩性为中粒斑状黑云母正长花岗岩,属于高钾钙碱性系列,具有高SiO2(74.57～76.15 wt%)、高碱(Na2O+K2O=7.15～8.48 wt%)、低MgO(0.19～0.31 wt%)的特征,属于准铝质-过铝质花岗岩。岩石轻稀土富集,重稀土亏损,具强的负Eu异常,富集大离子亲石元素如Rb、Th、U、K等,明显亏损Nb、Ta,强烈亏损Ba、Ti、Sr、P,具高104Ga/Al、FeOt/MgO、K2O/Na2O比值和高(Zr+Nb+Ce+Y)含量,具有铝质A型花岗岩特征。结合区域资料,翁田铝质A型花岗岩的出现,表明海南岛在中三叠世处于伸展环境。 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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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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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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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
18.
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
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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