内蒙花敖包特Pb-Zn-Ag多金属矿床原生晕分带特征与深部矿体预测模型

花敖包特Pb-Zn-Ag多金属矿床构造上位于滨西太平洋成矿域内蒙古大兴安岭成矿带南段, 是一个近年来发现的与白垩纪早期构造岩浆活动有关的隐伏热液脉状矿床.研究表明: (1)矿体原生晕发育, 且分带明显.据其异常强度建立的元素横向分带顺序(从强到弱)为Cd→Pb→Zn→Ag→Sb→In→Hg→As→Cu→Sn→W→Mo→Bi, 排在序列前面的Cd、Pb、Zn、Sb、Ag等5种元素, 可作为远矿指示元素; 排在序列后端的As、Bi、Mo、W等4种元素, 可作为近矿指示元素.(2)根据Grigorian原生晕分带计算方法, 获得矿体原生晕轴向分带序列(自矿体头部至尾部)为Sb→Pb→Cd→Ag→Zn→Hg→Cu→In→As→Bi→Sn→Mo→W, 与Grigorian建立热液矿床标准分带基本一致.(3)构建深部矿体找矿模型, 其预测评价指标(Sb×Pb×Cd×Ag)_D/(As×Sn×Mo×W)_D在矿体头部为1.30、矿体中上部为0.35、矿体中下部为0.056、矿体尾部为0.005, 这表明该指标随深度的增加有规律地降低, 是预测深部矿体资源潜力的有效指标.      

豫西龙门店银矿K4矿体原生晕特征及深部预测

对龙门店银矿K4矿体Au、Ag、Cu、Pb、Zn、W、Mo、Hg、As、Sb、Bi等11种微量元素的原生晕特征进行研究,为矿体深部成矿预测提供理论依据。微量元素统计学分析表明,Pb、Zn可作为矿体主要的近矿指示元素,矿体的成矿过程具有多期次叠加的特点;分析K4矿体原生晕地球化学参数垂向变化规律,发现矿体前缘和中部分别表现出明显的尾晕指示元素强异常和前缘晕指示元素强异常;计算得到矿体自上而下的轴向分带序列为W—Mo—Au—Hg—Cu—As—Bi—Zn—Ag—Sb—Pb,出现了明显的"前尾晕共存"和"反向分带"现象。依据上述K4矿体原生晕特征,建立了矿体原生叠加晕模型,并预测矿体深部存在规模较大的盲矿体,909 m标高以下有较大的找矿潜力。     

西藏驱龙斑岩铜钼矿地球化学异常特征

驱龙铜矿发育多元素的岩石地球化学异常.成矿元素Cu、Mo、(Ag)异常强、规模大,异常与矿化区一致;伴生元素Au、Bi、Pb、As、Sb、Hg异常在Cu、Mo异常边部并套合产出的B Co、Ni Mn Zn的异常主要分布铜钼矿化带外侧.Na₂O在矿化区显示负异常,K₂O为正异常.从异常元素组合、水平分带性和贫Na₂O、富K₂O的成矿环境表明,矿床属典型的斑岩型铜矿地球化学特征,并受到了强烈的剥蚀.     

四川大岩子铂-钯矿床的原生地球化学异常特征及盲矿预测

迄今为止文献中未见有铂矿原生晕研究的报道,通过对大岩子矿区地表和不同中段坑道原生晕的研究,发现在铂-钯矿体周围有清晰的F、Sb、Cd、Hg、As、Ag、Au、Pd、Pt、Cu、Ni元素的原生晕,其中F、Sb、Cd、Hg、As为前缘指示元素,Au、Ag为近矿指示元素,Pt、Pd、Cu、Ni为成矿指示元素.元素的垂直分带序列为(地表至矿体):(F、Sb、Cd、Hg、As)-(Ag、Au)-(Pd、Pt)-(Cu、Ni).地表岩石地球化学测量发现的Ⅲ号Pd、Pt异常带,具有多元素异常组合特征,判断为矿致异常,推测在该异常带下方可望找到隐伏矿体.坑道原生晕研究发现,在PD4中段出现浓集中心醒目、浓度分带清晰的F原生晕,推测在PD4中段下方可能存在新的盲矿体.     

河南铁炉坪银矿床地球化学特征研究

铁炉坪银矿床成矿溶液具有一低温，低盐度特征，可能来自于岩浆期的热液。成矿作用受太古界太华群，燕山期岩浆活动和构造活动三要素控制，太华群和燕山期岩浆岩可能提供了矿源。矿床原生地球化学异常具Ag,Pb,Cu,Zn,Au,Sb,As和Hg多元素组合特征，异常分带序列自下而上为Bi,Mo,Cu,Au→Ag，Pb,Zn→Hg,As,Sb。     

利用累加指数对老湾金矿带地表及深部含矿性评价

老湾金矿带是桐柏-大别山(北坡)金银成矿带的重要组成部分,位于金银成矿带的南亚带。在对该成矿带成矿地质背景和原生地球化学异常分析研究的基础上,采用矿体前缘元素As,Sb和尾部元素Mo,Pb(Ni)的累加比值: (As+Sb) /(Mo×10+Pb)和(As+Sb) /(Mo×10+Ni),确立了该矿带的累加指数评价指标。利用累加指数结合原生地球化学异常元素组合,对该矿带地表及深部的含矿性进行预测评价,扩大了原矿体规模且发现了新矿体。     

珲春黑山金铜矿区地球化学垂向分带研究

文章以黑山金铜矿区zK001钻孔资料为基础,对该区矿化进行了矿物学、成矿元素地球化学垂向分带研究.矿物学研究表明矿区由地表向深部,夕卡岩蚀变带由外带逐渐过渡为内夕卡岩带,再过渡为正常的闪长岩.以改良格里戈良分带指数法为主,辅以重心法,确定此矿床元素综合分带序列由浅到深为①Cu Sb Zn Ag;②Au Ni As Co Zn Hg Bi.与矿床浅部以铜矿体为主,深部以铜金矿体为主的地质事实相符合,并与矿物学分带相一致.     

胶东大型金矿床的地球化学分带特征

胶东地区大型、特大型金矿都严格受构造控制,具有多期多阶段叠加成晕特点,一般都有1~2个主成矿阶段.在矿体周围能形成异常的元素有Au、Ag、Cu、Pb、Zn、As、Sb、Bi、Mo、Hg、Co、Mn、Ni、W（F、B）等元素.单阶段形成的晕具有明显的垂直分带,Hg、As、Sb（B、F）强异常总是分布在矿体上部及前缘,而Bi、Mo、Mn、Co、Ni的强异常总是分布于矿体下部及尾晕,Au、Ag一般正相关,Cu、Pb、Zn有时偏于矿体上部,有时偏于下部.典型金矿床的元素组合及矿床地球化学异常垂直分带特征是研究金矿床原生叠加晕叠加结构、建立矿床叠加晕模型、确定盲矿体预测的重要标志.     

福建紫金山矿田罗卜岭斑岩型铜钼矿地球化学立体探测示范

罗卜岭矿床是与晚中生代花岗闪长斑岩体有关的隐伏斑岩型铜钼矿床,矿区位于紫金山矿田的东北部;铜钼矿体主要产于绿泥石化-绢英岩化和(弱)钾化-绢英岩化带中,矿石矿物组合为黄铜矿+辉钼矿;少量过渡类型矿体产于高级泥化带中,矿石矿物组合为蓝辉铜矿+铜蓝+辉钼矿.罗卜岭矿区的原生晕地球化学三维模型显示,微量元素具有一定的分带特征,低温元素Au与高温元素组合W、Sn、Bi分布于矿体上方,中低温元素Pb、Zn、Ag分布于Cu、Mo元素之间;元素直观垂向分带序列大致为:(As、Sb、Hg)-(W、Bi、Sn)-Ga-Au、Ba-Cu、Ag-Pb、Zn-Mn-Mo;前缘晕的元素与氧化物组合为As、Sb、Au、Ga、Al2O3,矿体近矿晕元素组合为Ag、Pb、Zn,缺失尾晕元素组合;Cu、Mo可直接作为找矿指示元素,Au、Ag、Pb、Zn、As、Sb、Ga、Ba、Mn可作为间接指示元素,矿床深部K2O正异常与Al2O3负异常可作为斑岩型铜钼矿的重要找矿标志,这一规律对紫金山矿田深部和外围隐伏斑岩型矿体的勘查工作具有重要的参考意义.     

热带雨林景观区土壤测量的应用效果

老挝中部、北部热带雨林地区的大地构造位置大致处于北西向长山岩浆—构造带和北东向琅布拉邦岩浆—构造带的交汇部位。该区域地表土壤测量分析表明,Cu与Pb、Zn、Ag、Sn、Mo、Sb、Hg、As、Cd、Co、B i总体呈共消长关系,为最佳元素组合。本区Cu、Pb、Zn等主要成矿元素沿花岗岩与灰岩接触带分布,Cu、Pb、Zn相关性不大并具有明显的分带性,Cu分布于接触带靠近花岗岩一侧,Pb、Zn分布于接触带靠近灰岩一侧,共伴生组分Mo、Sn、B i、Ag、Cd等异常明显。本区的元素组合可划分为5类:①Cu与Ag;②Pb与B i;③Zn与Cd;④Sn与Mo;⑤Sb与Hg、As。从元素分布特征看,本区具有矽卡岩的成矿特征,同时又可能有斑岩成矿的潜力。     

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