东秦岭上宫金矿成矿流体与成矿物质来源新认识   总被引：3，自引：0，他引：3  

胡新露  何谋春  姚书振 《地质学报》2013,87(1):91-100

上宫金矿床位于华北克拉通南缘的熊耳地体之中,是典型的构造蚀变岩型金矿.本文对上宫金矿的同位素地球化学资料进行了系统分析和综合研究,对其成矿物质和成矿流体的来源取得了一些新的认识.氢-氧-碳同位素体系研究表明,成矿流体并非来自燕山期岩浆热液,也不是来自于太华群或者官道口群和栾川群的变质脱水作用,而主要来自深部地幔或者由幔源岩浆派生,并在成矿的过程中逐渐向大气降水演化.硫-铅-锶同位素体系指示成矿物质为壳幔混合来源,地幔和太华群可能均提供了部分成矿物质.印支期华北与扬子板块发生碰撞对接时导致了强烈的壳幔相互作用,并驱动深部流体向上运移,上官金矿正是在这种构造背景下形成的.  相似文献   

Rb-Sr Dating of Pyrite and Quartz Fluid Inclusions and Origin of Ore-forming Materials of the Jinshan Gold Deposit,Northeast Jiangxi Province,South China     

MAO Guangzhou  HUA Renmin  LONG Guangming  LU Huijuan 《《地质学报》英文版》2013,87(6):1658-1667

The Jinshan gold deposit is located in the Northeast Jiangxi province,South China,which related to the ductile shear zone.It contains two ore types,i.e.the alteration-type ore and the goldbearing quartz vein ore.Rb-Sr age dating is applied to both gold-bearing pyrite in the alteration-type ore and fluid inclusion in the gold-bearing quartz vein to make clear the time of the gold mineralization of the Jinshan deposit.Analytical results of this study yielded that the age of the alteration-type ore bodies is about 838±110Ma,with an initial 87Sr/86Sr value of 0.7045±0.0020.However,the age of the gold-bearing quartz vein-type ore is about 379±49Ma,and the initial 87Sr/86Sr is 0.7138±0.0011.Based on the age data from this work and many previous studies,the authors consider that the Jinshan gold deposit is a product of multi-staged mineralization,which may include the Jinninian,Caledonian,Hercynian,and Yanshanian Periods.Among them,the Jinninian Period and the Hercynian Period might be the two most important ore-forming periods for Jinshan deposit.The Jinninian Period is the main stage for the formation of alteration-type ore bodies,while the Hercynian Period is the major time for ore bodies of gold-bearing quartz vein type.The initial values of the 87Sr/86Sr from this study,as well as the previous isotope and trace element studies,indicate that the ore-forming materials mainly derived from the metamorphic wall rocks,and the ore-forming fluids mainly originated from the deep metamorphic water.  相似文献   

云南富宁者桑金矿床硫铅同位素地球化学特征与成矿物质来源   总被引：3，自引：0，他引：3  

章永梅  顾雪祥  摆祥  刘瑞萍  郑硌  吴程赟  彭义伟 《地学前缘》2013,20(1):32-39

者桑金矿床赋存于上二叠统吴家坪组沉积碎屑岩中,矿体受构造破碎带控制,呈似层状、透镜状产出,是滇东南金成矿带上一个典型的卡林型金矿床。硫铅同位素地球化学研究显示,沉积黄铁矿和热液硫化物(黄铁矿和毒砂)的δ34S值均为正值,变化范围较窄(8.4‰～11.3‰),与二叠纪沉积时期海水硫酸盐δ34S值一致,具有地层硫的特征。矿石中的硫主要通过地层中有机质与海水硫酸盐的热还原作用(TSR)提供。铅同位素组成中,206Pb/204Pb变化范围较宽,207Pb/204Pb和208 Pb/204 Pb较为稳定,计算获得的模式年龄变化范围大(-62～389Ma),甚至出现"负年龄",表明除正常铅外,还有较多的放射性成因铅的混入。铅主要来自于上地壳,有少量岩浆物质的混入。矿石与围岩的硫铅同位素具有一定的继承性,成矿物质主要来自地层。  相似文献   

玄武岩标准样品铁铜锌同位素组成   总被引：7，自引：7，他引：0  

唐索寒  闫斌  朱祥坤  李津  李世珍 《岩矿测试》2012,31(2):218-224

报道了三种玄武岩标准样品(BCR-2、BIR-1a和GBW 07105)的铁铜锌同位素数据。实验使用HNO3-HF混合酸消解玄武岩标准样品;AGMP-1阴离子交换树脂分离提纯样品中的铜铁锌,利用多接收等离子体质谱仪(MC-ICPMS)测定铁铜锌同位素比值,分析过程中使用样品-标准-样品交叉法校正仪器的质量分馏。实验得到BCR-2、BIR-1a和GBW 07105标准样品的高精度铁铜锌同位素组成(95%置信水平的不确定度)分别为:δ56FeBCR-2-IRMM014=0.070‰±0.018‰(2SD),δ65 CuBCR-2-SRM976=0.16‰±0.04‰(2SD),δ66 ZnBCR-2-IRMM3702=-0.072‰±0.020‰(2SD);δ56 FeBIR-1a-IRMM014=0.044‰±0.026‰(2SD),δ65CuBIR-1a-SRM976=0.027‰±0.019‰(2SD),δ66 ZnBIR-1a-IRMM3702=0.085‰±0.032‰(2SD);δ56FeGBW 07105-IRMM014=0.126‰±0.039‰(2SD),δ65 CuGBW 07105-SRM976=0.12‰±0.01‰(2SD),δ66ZnGBW 07105-IRMM3702=0.22‰±0.03‰(2SD)。这些数据在误差(不确定度)范围内与国际上已发表的数据是一致的。三个玄武岩标准样品的铁铜锌同位素组成数据的发表为铁铜锌同位素研究提供了统一的标准,使地质样品的铁铜锌同位素数据的质量监控成为可能。  相似文献   

分析系数法用于评价农业地质调查样品52个项目分析质量等级     

王烨  陈爱平 《岩矿测试》2012,31(2):355-360

土壤地球化学样品分析测试质量控制目前采用内部质量控制和外部质量控制相结合方法,重点从准确度、精密度、虚拟图等方面确保元素地球化学图成图质量,应用效果良好,不足之处是规范未规定统一的分析方法及评价分析质量等级的参数。分析系数是评价分析结果准确度和精密度的一个综合指标,既适用于实验室内部质量控制,又适用于实验室间质量控制,其评价方法简便易懂、量化直观,但在地矿实验室较少应用,有较好的推广应用价值。文章应用分析系数法评价河南省农业地质调查样品中4个日常监控土壤标准物质中52个项目的分析质量水平。依据多目标区域地球化学调查规范(1∶250000)相关指标计算出分析系数允许限,划分了质量评定等级并进行了实际应用。研究结果显示,4个土壤标准物质共208个分析项目中,其中138个项目达到优秀级,58个项目为良好级,12个项目为及格,总体分析质量好。对分析质量差的Se、Cr、I、Br、Th、C、Pb、Cd等8个项目,应查明原因,采取相应措施,提高这些项目分析的准确度和精密度。  相似文献   

微晶白云母对环氧灌注胶电阻率和抗压强度的影响     

罗柯  汪灵  雷燕  李自强 《矿物学报》2012,32(3):403-408

为了克服现有绝缘灌注胶用非金属矿物填料存在的不足,为新型绝缘灌注胶的制备与应用提供科学依据,采用PC68型数字高阻计和与之配套使用的适用于直径为Ф=18 mm的小块样品电阻率测试的自制小型电极实验装置,以及WE-100型液压万能试验机等,研究微晶白云母用量对E-51环氧树脂绝缘灌注胶电阻率和抗压强度的影响,并采用扫描电镜（SEM）对材料的微观组织结构进行了分析,结果表明：微晶白云母对绝缘灌注胶体积电阻率基本上没有不利影响,而对绝缘灌注胶表面电阻率有一定改善作用,当用量为40 phr时,其表面电阻率可达7.53×1014Ω;微晶白云母用量〈100 phr时,绝缘灌注胶的抗压强度会随用量的增加而增大,而用量〉100 phr时,抗压强度则迅速降低;从绝缘灌注胶绝缘性能、力学性能和胶液黏度等因素考虑,微晶白云母的优化用量为80 phr。  相似文献   

建筑文物中石灰质修复材料的研制     

张东丽  刘鑫  戴仕炳  张培萍 《世界地质》2012,31(3):599-602

为实现对建筑文物的“原真性”修复,利用X 射线衍射仪和激光粒度分布仪测定了历史建筑物中原胶凝材料矿物的组成和结构,并采用湿化学方法对原勾缝剂进行物料组成的复原,证明历史勾缝剂材料主要为石灰基材料。在复原的原胶凝剂材料配方的基础上分别加入活性火山灰、木质纤维素、分散性胶粉、早强剂和减水剂等对勾缝剂进行性能改进。经反复试验优选出了修复用勾缝剂材料的配方,并测试了试样的各项物理性能。结果表明,修复材料抗压强度达14. 47 MPa,饱和吸水率为 27. 07%,体积变化率＜ 1%,冻融循环4 次不变,证明改性后勾缝剂材料可以满足修复胶凝材料的性能要求。  相似文献   

Production and Certification of a Unique Set of Isotope and Delta Reference Materials for Boron Isotope Determination in Geochemical,Environmental and Industrial Materials     

Jochen Vogl  Martin Rosner 《Geostandards and Geoanalytical Research》2012,36(2):161-175

Isotopic reference materials are essential to enable reliable and comparable isotope data. In the case of boron only a very limited number of such materials is available, thus preventing adequate quality control of measurement results and validation of analytical procedures. To address this situation a unique set of two boron isotope reference materials (ERM‐AE102a and ‐AE104a) and three offset δ¹¹B reference materials (ERM‐AE120, ‐AE121 and ‐AE122) were produced and certified. The present article describes the production and certification procedure in detail. The isotopic composition of all the materials was adjusted by mixing boron parent solutions enriched in ¹⁰B or ¹¹B with a boron parent solution having a natural isotopic composition under full gravimetric control. All parent solutions were analysed for their boron concentration as well as their boron isotopic composition by thermal ionisation mass spectrometry (TIMS) using isotope dilution as the calibration technique. For all five reference materials the isotopic composition obtained on the basis of the gravimetric data agreed very well with the isotopic composition obtained from different TIMS techniques. Stability and homogeneity studies that were performed showed no significant influence on the isotopic composition or on the related uncertainties. The three reference materials ERM‐AE120, ERM‐AE121 and ERM‐AE122 are the first reference materials with natural δ¹¹B values not equal to 0‰. The certified δ¹¹B values are ?20.2‰ for ERM‐AE120, 19.9‰ for ERM‐AE121 and 39.7‰ for ERM‐AE122, each with an expanded uncertainty (k = 2) of 0.6‰. These materials were produced to cover about three‐quarters of the known natural boron isotope variation. The ¹⁰B enriched isotope reference materials ERM‐AE102a and ERM‐AE104a were produced for industrial applications utilising ¹⁰B for neutron shielding purposes. The certified ¹⁰B isotope abundances are 0.29995 for ERM‐AE102a and 0.31488 for ERM‐AE104a with expanded uncertainties (k = 2) of 0.00027 and 0.00028, respectively. Together with the formerly certified ERM‐AE101 and ERM‐AE103 a unique set of four isotope reference materials and three offset δ¹¹B reference materials for boron isotope determination are now available from European Reference Materials.  相似文献   

A Method for Rapid Determination of Re and Os Isotope Compositions Using ID‐MC‐ICP‐MS Combined with the Sparging Method     

Tatsuo Nozaki  Katsuhiko Suzuki  Gregory Ravizza  Jun‐Ichi Kimura  Qing Chang 《Geostandards and Geoanalytical Research》2012,36(2):131-148

A simple, rapid method for the determination of Re and Os concentrations and isotope compositions using isotope dilution multi‐collector inductively coupled plasma‐mass spectrometry (ID‐MC‐ICP‐MS) combined with Carius tube digestion and sparging introduction of Os was developed. For Os measurement, four channeltron ion counters to detect different Os isotopes were used simultaneously, which led to a drastic reduction in the measurement time. Rhenium isotopes were measured by means of eight Faraday cups with solution nebulisation and an ultrasonic membrane desolvator. The representative ¹⁸⁸Os count rate of an Os standard solution containing 50 pg of total Os was approximately 110000–120000 cps at the onset of measurement; the Re intensity of our in‐house 10 pg g^?1 standard solution reached 1820 V/μg g^?1 with a sample uptake rate of 95–99 μl min^?1. These values indicate that the sensitivity of the method was sufficient even for samples with low Re and Os concentrations, such as chert. As the temporal variations of the amplification efficiency of the ion counters differed from one another, we adopted a sample‐calibrator bracketing method to correct the measured Re and Os isotope ratios. The Re and Os concentrations via the isotope dilution method and the ¹⁸⁷Os/¹⁸⁸Os ratios of two sedimentary rock reference materials (JMS‐2 and JCh‐1) on the basis of the isotope ratios determined by the MC‐ICP‐MS and by negative thermal ionisation mass spectrometry (N‐TIMS) were comparable within their ranges. Based on Os isotope measurement of the IAG reference material [Durham Romil Os (DROsS)], the average difference from the recommended value and precision of Os isotope measurements by the sparging method in combination with multi‐ion‐counters were 0.72% and 0.76% [1RSD (%), n = 29], respectively. The precisions in the ¹⁸⁷Os/¹⁸⁸Os ratios [1RSD (%)] of JMS‐2, JCh‐1 and DROsS were 0.35–0.71, 1.56–3.31 and 0.99–1.28%, respectively, which depended on their Os ion intensities. No systematic difference was observed between the Re and Os geochemical compositions of JCh‐1 and JMS‐2 obtained by means of digestion with inverse aqua regia and CrO₃‐H₂SO₄ solutions, suggesting that either acid solution can be used for the sparging method of sedimentary rock samples. As CrO₃‐H₂SO₄ solution is believed to liberate predominantly the hydrogenous Re and Os fraction from organic‐rich sediment, the sparging method combined with CrO₃‐H₂SO₄ digestion and multi‐ion‐counters in the mass spectrometry is expected to be a powerful tool for reconstructing the secular change in marine Os isotope compositions with high sample throughput.  相似文献   

Analysis of the steady‐state flow of a compressible viscoplastic medium over a wedge     

Oana Cazacu  N. D. Cristescu  M. J. Schmidt 《国际地质力学数值与分析法杂志》2006,30(6):489-499

A new model for calculating the resistance to penetration into geological or geologically derived materials is proposed. We assume steady‐state flow of the target material over the penetrator. The target medium is described by a rate dependent constitutive equation that accounts for combined effects of strain rate and compaction on yielding. The wedge‐shaped penetrator is considered to be rigid. The influence of the characteristics of the penetrator/target interface, impact velocity, target mechanical properties and nose geometry on the resistance to penetration is investigated. It is found that for low to intermediate impact velocities, accounting for friction results in a blunter optimal wedge geometry for optimal penetration performance. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献