猫岭——王家崴子金矿区伴生元素的分布特征

对猫岭－王家葳子金矿区矿石中伴生的微量元素研究表明，猫岭金矿的As,Cd,B,Be,Sn,Bi,Pb,Sb明显偏高，其中As,Cd,B高度富集，Bi,Sb,Sn,Be,Pb中度富集；王家崴子金矿Pb,Cr,Cd,Zn,Be,Sn,As明显偏高，其中Cd,Bi,As,Pb,Sn高度富集，Cu为中度富集。矿石中As,Bi,B含量较高与赋矿围岩中该元素高的原始富集有关。岩矿显微鉴定和多种数理统计分析综合研究表明，Pb,Zn,Cu主要以方铅矿、闪锌矿、黄铜矿和黝铜矿等独立矿物形式存在，部分呈类质同像形式分布于黄铁矿、毒砂等硫化物中。As以毒砂形式存在，部分以类质同像形式存在于黄铁矿、雌黄铁矿、白铁矿和黝铜矿中：Sb,Bi以固溶体混入物形式分布于黄铁矿、毒砂和黝铜矿中；Sn,B以独立矿物形式赋存于黄铁矿、方铅矿和黝铜矿中；Cd与方铅矿和闪锌矿、黝铜矿有关；部分Cr,Be,B与云母和粘土矿物有关。     

新疆包古图斑岩铜矿磁黄铁矿和毒砂成因及其成矿指示意义

新疆准噶尔盆地西缘包古图斑岩铜矿是中亚成矿域内首例确认的还原性斑岩铜矿,具有区别于氧化性斑岩铜矿的矿物学特征。包古图斑岩铜矿的成矿闪长岩发育钾硅酸盐蚀变和绢英岩化蚀变及少量青磐岩化蚀变,铜矿化主要集中在钾硅酸盐蚀变阶段和绢英岩化蚀变阶段。钾硅酸盐蚀变和绢英岩化蚀变两阶段发育不同的金属矿物共生组合：前者发育磁黄铁矿,具有黄铜矿+辉钼矿+黄铁矿+磁黄铁矿+钛铁矿+闪锌矿±毒砂组合,黄铁矿主要呈细粒—粗粒五角十二面体,富集Cu而亏损As;后者发育毒砂和碲铋矿物,出现与毒砂共结晶的碲化铋以及不含其他硫化物的独立毒砂脉体,具有辉钼矿+黄铜矿+黄铁矿+毒砂+闪锌矿±碲铋矿物组合,黄铁矿主要呈粗粒立方体,黄铁矿和毒砂中均富集Au+Ag+Te+Bi。钾硅酸盐蚀变和绢英岩化蚀变阶段的硫化物具有不同的组成、结构和成分,反映了绢英岩化蚀变阶段As—Au—Ag—Te—Bi矿化和钾硅酸盐蚀变阶段Cu—Mo—Au—Ag矿化叠加的关系。利用磁黄铁矿和毒砂成分反演了其形成温度和硫逸度,钾化蚀变阶段的温度和硫逸度分别为267~600℃和-1.5~-9.5;绢英岩化蚀变阶段的温度和硫逸度分别为209~325℃和-15.8~-9.7,同时构建了不同阶段的矿物组合相图,结果显示磁黄铁矿的形成和早期低氧逸度流体相关,毒砂的形成与流体温度降低和硫逸度降低相关。同时推断在早阶段Cu—Mo—Au—Ag矿化期和晚阶段As—Au—Ag—Te—Bi矿化期,由于温度和硫逸度存在差异,Cu和As经历了不同的反应沉淀过程。     

招远大尹格庄金矿床微量元素特征及其意义

该文以山东招远大尹格庄金矿床中微量元素为研究对象,通过对矿床围岩、矿石等微量元素的研究,表明大尹格庄金矿围岩中微量元素以富含 Bi,Au,Pb,W,Ag,Sn 为特点,矿体和矿化体中元素组合为 Au,Ag,As,Sb,Hg,B, Cu,Zn,Bi,Mo,Mn,Co,Ni,W。在5个成矿阶段中,第二阶段与第三阶段微量元素的富集程度较明显,表现为 Au, Ag,As,Co,Bi,Cu,Pb,Zn 等的富集,成矿元素可分为2个分带序列,主成矿元素为 Au Ag Cu Pb Zn Bi 组合、头晕元素 As Sb Hg 组合和尾晕元素 Co Ni 组合。     

安徽省休宁县小贺毒砂——多金属伴生金矿地质地化特征及找金前景浅析

小贺毒砂～多金属矿矿石中部分样品的含金品位可达≥0．3g/t,明显具备伴生金矿产地特征,矿床赋存于晋宁晚期的灵山片麻状花岗岩岩体的断裂带中,岩体遭受强烈挤压破碎和广泛的矿化蚀变,岩石Au、Ag、Pb、Zn、As及Sb、Bi、Cu、Mo异常显著,Au/Ag比值0．03,Co/Ni比值＞1,Pb/Zn比值＞2,Sb/Bi比值＞2,反映出良好的含金性,剥蚀程度较低,具备寻找蚀变岩型金矿床的地质条件。特别值得指出的是1号矿体矿石含金达工业品位,尚有一定广度和深度的矿化蚀变带的存在,小贺毒砂～多金属伴生金矿值得进一步评价。     

热液型金矿床围岩蚀变过程中元素迁移规律--以张家口地区东坪、后沟、水晶屯金矿为例

张家口地区东坪、后沟、水晶屯金矿围岩蚀变发育 ,主要的蚀变类型有钾长石化、硅化、黄铁矿化、绿泥石化等。通过蚀变岩常量元素、微量元素的定量计算发现 ,三个金矿床围岩蚀变过程中元素迁移、富集有明显的规律 ,即常量元素 (SiO2 、K2 O、FeO) ,亲硫元素 (成矿元素 :Au、Ag、As、Sb、Bi、Pb、Zn)明显富集 ,其它亲铜亲铁元素 (Cr、Co、Ni、Cu)略有富集。蚀变热液是一种来自深部的携带亲硫元素富硅的碱性流体     

胶东山后金矿床地质体微量元素特征及找矿意义

对胶东招平断裂上的山后金矿34个钻孔进行了原生晕测量,分析了Au、Ag、cu、Pb、zn、As、Sb、Bi、Mo、Hg等10种元素,统计了胶东岩群、荆山群、玲珑花岗岩及招平断裂蚀变带中微量元素含量及变化.变质岩、花岗岩均富Bi、Ag,而贫Hg、Sb、Au、Cu、zn、As;胶东岩群、荆山群中金的丰度值相近,它们均为金矿的矿源岩;在招平断裂蚀变带中Au、Ag、Pb、Mo、Bi等元素出现了明显富集,而Cu、zn、Sb、Hg等元素没有富集,矿床多金属硫化物阶段不发育;根据聚类分析结果,Au与Ag、Cu、Pb、zn生成于不同的成矿期,招平断裂中的Au矿体形成于金成矿期,招平断裂上盘荆山群地层中的Au、Ag、cu、Pb、Zn多金属矿体形成于金银多金属成矿期;招平断裂北段的成矿条件要比南段好;根据As、Mo元素含量的变化,确定出山后金矿深部矿体预测的简单准则,并对金矿深部进行了简单成矿预测.     

玲珑金矿大开头矿区47号脉微量元素特征

选择胶东玲珑金矿典型矿体47号脉为研究对象,应用基岩地球化学方法,测试微量元素含量,研究微量元素与金的相关关系、计算微量元素的浓集系数并确定其轴向分带,探讨微量元素对深部金成矿的指示意义,期待能对玲珑金矿深部找矿提供一些参考.初步认识如下:矿区金矿体的最佳指示元素依次为Au、Ag、Bi、As、Cu、Co、Mo、Sb;金矿体的轴向分带序列从上到下依次为As、Pb、Ag、Cu、Hg、Sb、Mo、Ni、Th、V、U、Mn、Zn、Bi、Co、Au;矿体中Au、Bi、Ag、As富集系数大,Cu、Co富集系数中等,而Zn在矿体中相对亏损.研究结果表明,在深部47号矿体仍有较好的成矿前景.     

河南省嵩县萑香洼金矿矿床地球化学特征

莅香洼金矿发育有与金矿关系密切的地球化学异常,Au及相关元素的平均含量从安山岩→蚀变安山岩→蚀变岩→矿化蚀变岩呈几何级数递增。沿F985构造蚀变带走向,Pb、Ag与Au的组合异常通常与金的矿体晕分布一致,而As、Sb组合则更多反映了矿体前缘晕的组合特点,沿倾向,Au及相关元素自浅而深具有分段富集特征,并在1023m标高和976m标高构成二个浓集中心。其理想的元素轴向分带序列为：前缘晕As、Sb—Ba,矿体晕Au、Ag、Pb、Zn、Cu、Mo,矿尾晕（Cu、Mo）-（Co、Ni、Bi）。文章在前人研究的基础上,系统总结了莅香洼金矿床的地球化学特征,总结了构造蚀变岩型金矿床的地球化学找矿标志,建立了萑香洼金矿床的地球化学找矿模型。     

内蒙古香林香达铜矿区地球化学找矿研究

针对矿区地表及井下四个中段共采集地层和构造蚀变岩样品194件,分析Ti、V、Cr、Mn、Co、Ni、Au、Ag、Cu、Pb、Zn、W、Sn、Mo、Bi、As、Sb、Hg等18种微量元素含量,编制各元素地球化学0号勘探线横剖面图,综合利用地球化学图件分析法与格里戈良分带指数法,确定元素的轴向分带序列。通过地质地球化学资料可知,石英闪长岩、构造蚀变岩中Cu、Ag、As、Au、Mo、Sn元素含量高,变异系数大,表明这些元素参与成矿蚀变作用。矿区原生晕轴向分带序列为:(Zn、Cr1、Hg1、Ni、As)→(Pb、V、Mn、W、Cr_2、Ti)→(Hg_2、Sb、Co、Bi、Sn、Ag、Au、Mo、Cu),根据元素地球化学横剖面图中主成矿元素异常高值带向下延伸未封闭、矿体向下未尖灭、特征前缘晕元素Hg、成矿晕元素Cu出现矿尾晕等特征,说明矿体向下仍有一定的延伸,预示着深部具有一定的找矿潜力。     

半宽金矿床微量元素地球化学研究

半宽金矿床有两类矿石:石英-黄铁矿型和石英-多金属硫化物型。微量元素研究表明元素组合为Bi、Pb、Au、Ag、Zn、Sb、W、Cu、As、Mo。矿石中铅含量是区分黄铁矿型矿石和多金属硫化物矿石的重要指际。金矿化与Co/Ni、Cu+Pb、Rb/Sr值密切相关。1号脉和9号脉矿石微量元素的对比研究表明9号脉Au与Mo、Ag、Hg,As、Pb具显著正相关;1号脉Au与其他元素相关性不明显。9号脉经历三次金矿化,1号脉仅有一次金矿化。从矿石微量元素地球化学研究结果分析,9号脉下部仍有延伸。     

The terrestrial fauna of the Late Triassic Pant-y-ffynnon Quarry fissures,South Wales,UK and a new species of Clevosaurus (Lepidosauria: Rhynchocephalia)

Pant-y-ffynnon Quarry in South Wales yielded a rich cache of fossils in the early 1950s, including articulated specimens of new species (the small sauropodomorph dinosaur Pantydraco caducus and the crocodylomorph Terrestrisuchus gracilis), but no substantial study of the wider fauna of the Pant-y-ffynnon fissure systems has been published. Here, our overview of existing specimens, a few described but mostly undescribed, as well as freshly processed material, provides a comprehensive picture of the Pant-y-ffynnon palaeo-island of the Late Triassic. This was an island with a relatively impoverished fauna dominated by small clevosaurs (rhynchocephalians), including a new species, Clevosaurus cambrica, described here from a partially articulated specimen and isolated bones. The new species has a dental morphology that is intermediate between the Late Triassic Clevosaurus hudsoni, from Cromhall Quarry to the east, and the younger C. convallis from Pant Quarry to the west, suggesting adaptive radiation of clevosaurs in the palaeo-archipelago. The larger reptiles on the palaeo-island do not exceed 1.5?m in length, including a small carnivorous crocodylomorph, Terrestrisuchus, and a possible example of insular dwarfism in the basal dinosaur Pantydraco.     

The effect of water on accessory phase solubility in subaluminous and peralkaline granitic melts

The solubilities of columbite, tantalite, wolframite, rutile, zircon and hafnon were determined as a function of the water contents in peralkaline and subaluminous granite melts. All experiments were conducted at 1035 °C and 2 kbar and the water contents of the melts ranged from nominally dry to approximately 6 wt.% H₂O. Accessory phase solubilities are not affected by the water content of the peralkaline melt. By contrast, solubilities are affected by the water content of the subaluminous melt, where the solubilities of all the accessory phases examined increase with the water content of the melt, up to 2 wt.% H₂O. At higher water contents, solubilities are nearly constant. It can be concluded that water is not an important control of accessory phase solubility, although the water content will affect diffusivities of components in the melt, thus whether or not accessory phases will be present as restite material. The solubility behaviour in the subaluminous and peralkaline melts supports previous spectroscopic studies, which have observed differences in the coordination of high field strength elements in dry vs. wet subaluminous granitic glasses, but not for peralkaline granitic glasses. Lastly, the fact that wolframite solubility increases with increasing water content in the subaluminous melt suggests that tungsten dissolved as a hexavalent species.     

Quaternary stresses revealed by calcite twinning inversion: insights from observations in the Savonnières underground quarry (eastern France)

Calcite samples were extracted both from the rock matrix and the superficial coating of a karstified fault plane of an underground quarry, located in the eastern border of the Paris basin. The karstification is dated as Quaternary. Analysis of mechanical calcite twinning reveals that only the calcite matrix has also undergone a compression trending WNW that can be attributed to the Mio-Pliocene alpine collision. Both coating and matrix have undergone a strike-slip regime with σ₁ roughly trending north–south, that could correspond to the regional present-day state of stress, a strike-slip compression rather trending NNW, modified by local phenomena. To cite this article: M. Rocher et al., C. R. Geoscience 335 (2003).     

HYDROGEOLOGY

正20141756 Chen Ruige(Mathematical College,China University of Geosciences,Beijing100083,China);Zhou Xun Numerical Simulation of Groundwater Level Fluctuation in a Coastal Confined Aquifer with Sloping Initial Groundwater Level Induced by the Tide(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,32(7),2013,p.1099-1104,6 illus.,16 refs.) Key words:confined water,groundwater level     

METAMORPHIC PETROLOGY

正20141408 Cai Jia(Institute of Geology,Chinese Academy of Geological Sciences,Beijing100037,China);Liu Fulai Petrogenesis and Metamorphic P-T Conditions of Garnet-Spinel-Biotitebearing Paragneiss in Danangou Area,Daqingshan-Wulashan Metamorphic Complex Belt(Acta Petrologica Sinica,ISSN1000-0569,CN11-1922/P,29(7),     

SERIALS

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GEOPHYSICAL EXPLORATION

正20142386An Guoying(China Aero Geophysical Survey and Remote Sensing Center for Land and Resources,Beijing 100083,China)Application of Satellite Remote Sensing in Regional Hydrogeological Investigation:Taking Cenozoic Strata in Wenquan Sheet(1∶250 000)of Karakoram Range as an Example(Geosci-     

QUATERNARY GEOLOGY & GEOMORPHOLOGY

正20141016An Chengbang(Key Laboratory of Western China’s Environmental Systems,Ministry of Education,Lanzhou University,Lanzhou 730000,China);Zhao Yongtao Lake Records during the Last Glacial Maximum from Xinjiang,NW China and Their Climatic Impli-     

PETROLEUM GEOLOGY

正20141538 Cao Qing(School of Earth Sciences and Engineering,Xi’an Petroleum University,Xi’an 710065,China);Zhao Jingzhou Characteristics and Significance of Fluid Inclusions from Majiagou Formation,Yichuan Huangling Area,Ordos Basin(Advances in Earth Science,ISSN1001-8166,CN62-1091/P,28(7),2013,p.819-828,7 illus.,3 tables,43 refs.)     

GEOCHEMISTRY

正20142002 Wei Hualing(Institute of Geophysical and Geochemical Exploration,Chinese Academy of Geological Sciences,Langfang065000,China);Zhou Guohua Element Content and Mineral Compositions in Different Sizes of Soil in Tongling Area,Anhui Province(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,32(11),2013,p.1861