玻利维亚多尔各市D铜矿矿物元素组合分带及找矿预测

玻利维亚多尔各市D铜矿地处安第斯褶皱带中段,西科迪勒拉构造带东侧南端。矿体主要赋存于多尔各组二段(E3t2)地层中。通过对多尔各市D铜矿矿物分带、主元素及微量元素组合分析,采用数理统计分析方法。研究结果表明:(1)粉砂岩型矿化(Ⅰ型矿化):近矿硅化增加,矿化范围叠加石膏脉,围岩泥质(脉)含量减少,方解石化(隐晶质)发育减弱;远离矿化硅化减弱,石膏脉消失,方解石化增强,泥化增强。(2)砂砾岩型矿化(Ⅱ型矿化):近矿硅化增加,矿化范围叠加石膏脉,围岩泥质(脉)含量减少,方解石化(隐晶质)减弱;远离矿化段,硅化减弱,石膏脉消失,方解石化增强,泥化增强。(3)石英脉型矿化(Ⅲ型矿化):内带主要发育矿化、硅化,最显著的特征为发育大量矿化脉及石英脉;外带发育泥质脉及石英脉。(4)Cu—Ag元素组合为矿区重要的矿化元素组合内带,Ca—Mn元素组合为矿区近矿围岩褪色蚀变元素组合中带,U—V元素组合为矿区含矿"红层"元素组合外带。通过矿物分带、地球化学元素分析,确定找矿靶区,并在靶区探获铜矿量770.08万吨、平均品位1.77%、金属量136304t。     

甘肃花牛山金矿区热红外高光谱遥感特征分析与找矿预测

利用甘肃省花牛山金矿区热红外高光谱遥感数据(CASI/SASI/TASI)提取矿化蚀变矿物进行矿物填图,通过地面热红外高光谱测试验证其准确性,对热红外高光谱遥感矿化蚀变矿物分布规律和组合特征进行分析,结合矿床矿体特征、围岩蚀变特征,建立基于CASI/SASI/TASI数据蚀变矿物分带找矿预测模型。利用该模型在找矿预测区内进行找矿预测,新发现多处金、铜等多金属矿化线索,找矿效果显著,为热红外高光谱遥感蚀变矿物填图技术的推广应用提供了实例。     

阿尔泰阿舍勒铜锌矿床模型及找矿靶区预测

阿舍勒大型铜锌矿是我国典型的海相火山岩块状硫化物(VMS)型矿床,赋存于阿舍勒盆地早—中泥盆世阿舍勒组海相火山-沉积岩系中。结合阿舍勒铜锌矿最新勘探成果,通过对阿舍勒铜锌矿床矿物组合分带、矿石构造分带及成矿温度分带的研究,在Ⅰ号矿体9～21线0 m标高以下划分出一走向近NS向的火山喷流通道并总结了成矿模型。最终划分出Ⅰ号矿体9～21线-200 m以下及Ⅴ号矿化蚀变带深部两处找矿靶区。     

山东招远界河金矿床矿化垂向变化特征研究

界河金矿床作为胶东地区典型的蚀变岩型金矿床,目前通过坑道工程揭露已经探明其矿体垂深达800m左右。从矿区浅部向深部,其矿化呈现出一定的规律性变化:矿化类型呈现出浅部以蚀变岩型矿化为主、深部以裂隙脉型矿化为主的分带规律;矿体规模逐渐变小,矿化强度逐渐减弱,矿体产状也逐渐变缓。此外,矿物组分、矿石组构、围岩蚀变以及微量元素特征等从浅部向深部也均呈现出规律性的变化。结合区域内石英脉型和蚀变岩型金矿化的垂向分带特征,初步建立了胶东地区金矿化在垂向上的"三段式"分带模式:浅部以石英脉型矿化为主,中部以蚀变岩型矿化为主,深部则以裂隙脉型矿化为主。     

西南北海道地区早川、释迦坑矿床的铜铅锌矿化作用

早川与释迦坑矿床的铜铅锌矿化作用特征,集中表现在单位矿脉的构造、矿物组合、矿化阶段以及矿脉中石英和母岩氧同位素组成等方面.早川与释迦坑的矿床中,存在着黄铜矿—黄铁矿—黝铜了—方铅矿—伴有闪锌矿的石英脉(铜铅锌石英脉)以及方铅矿—伴有闪锌矿的石英脉(铅锌石英脉.铜铅锌石英脉较铅锌石英脉更早期形成.铜铅锌石英脉的矿物组合为黄铜矿、黄铁矿、黝铜矿—砷黝铜矿、方铅矿、闪锌矿、硫砷铜矿、车轮矿、板硫锑铅矿、碲银矿、黄锡锌矿、砷等轴硫钒铜矿、Cu-Fe-Zn-Sn-S系矿物、硫碲铋铅矿、硫铜铋铅矿、石英以及磷灰石.铅锌石英脉的矿物组合为方铅矿、闪锌矿、黄铁矿、黄铜矿、黝铜矿、银金矿及石英.随着矿化作用早期向晚期过渡,闪锌矿中的FeS含量有所减低.黝铜矿—砷黝铜矿的单一颗粒中,Sb与As之间的化学组成出现明显的非均质性.     

常宁县黄沙窿铜矿区原生晕特征

黄沙窿铜矿区热液矿床原生晕,严格受南北向与近东西向两组构造控制.与赤铁矿化、白云石化等围岩蚀变有密切关系。区内矿化蚀变与原生晕组分,有明显的垂直分带特征。其中Ⅱ矿带元素分带序列从上至下为Sb—As—Ag—Pb—Cu—Bi—Zn—(As)—Sn。据此可作为前缘与尾缘异常的评价依据。当地表矿体引起的原生异常中,包含明显的Sb、Ag异常,且Sb/Sn>0.3;蚀变以白云石化、赤铁矿化为主,矿石矿物主要为辉铜矿时,说明该矿体向深部尚有较大的延深,延深距离可用文中提到的线性方程来判断。笔者根据前缘异常评价指标,推测ZK_(13)与ZK_(24)间有盲矿存在。     

安徽铜山矽卡岩型铜矿床控矿构造及其对矿化的影响

矽卡岩型金属矿床的形成与构造活动是密切相关的。本文以安徽铜山矽卡岩型铜矿床为研究对象,通过对岩体侵位特征、矽卡岩矿化分带特征、和矿物组合变化规律的研究,系统分析了断裂、褶皱、不整合、接触带等构造活动对本区矽卡岩型铜矿床的成矿控矿意义以及对于矽卡岩矿化的影响。研究表明,构造运动贯穿岩浆上侵、就位、岩浆热液流体活动、接触交代、成矿等整个地质过程;岩浆侵位和矿体的赋存主要受不整合面控制;垂向上矽卡岩矿化分带不同,浅部矿体主要产于石炭-二叠系(C-P)灰岩与燕山期花岗闪长岩体形成的矽卡岩接触带上,而深部矿体则是由于岩浆热液流体的灌入式侵位,发生接触交代、矽卡岩化而成矿的;断裂-接触带共同控矿导致反向矽卡岩矿化分带。     

玲珑金矿田矿物组合与地球化学分带及矿体定位预测意义

详细讨论了玲珑金矿田矿物组合和元素的空间分带，二之间的一致性说明矿物组合的空间分带是宏观的元素地球分带，且具有远程有序和短程无序的特点。同时在矿田水平方向上，由于SE→NW金属矿物的种类和含量呈增加的趋势，由少硫化物蚀变岩型向多金属硫化物石英脉型变化。由于不同矿物组合的矿脉赋矿标高具有较大的差异，这为矿体的定位预测提供了矿物学依据；另外矿物组合的垂向分带，对判定矿体的剥蚀深度和延深也具有重要的参考价值。     

东准噶尔汉人沟钨多金属矿床成矿分带及找矿方向探讨

东准噶尔汉人沟钨多金属矿床具有铅、锌、金、钨等多元素成矿特征,发育硫化物型、石英脉型等矿化类型,不同部位形成不同的矿化类型和矿产。通过对矿体赋存部位、矿化类型分布及矿物和元素组合等特征的对比分析,研究矿床在水平和垂向上的矿化分带,对矿区及区域钨、铅、锌多金属矿找矿突破具有重要意义。该矿床水平方向上以辉绿岩为中心,代表中-低温的硫化物型矿化和铅锌矿分布于代表中高温白钨矿化的两侧;垂向上铅矿-锌矿-白钨矿-黑钨矿四个分带明显,形成地表到深部从中低温到高温的成矿分带特征。矿床水平和垂向分带明显,并且随着高程的降低,成矿中心向北东方向偏移。目前勘查深度相当于"五层楼式"钨矿的远端成矿部位,深部还具有较大的找矿潜力,找矿将取得较大突破。     

陕西双王金矿床轴(垂)向黄铁矿中微量元素变化规律及深部预测

凤太矿集区是秦岭重要的铅锌金多金属成矿区之一,双王金矿是该成矿区中典型的角砾岩型金矿床。本文采用格里戈良提出的原生晕分带指数法,详细研究了双王金矿床KT9矿体和KT8矿体中ZK18-5、ZK30-1和ZK40-53个坑内钻孔的原生晕轴(垂)向分带特征,通过各钻孔中原生晕分带指数垂向变化规律、微量元素衬值及地球化学参数分析进行深部矿化预测。结果显示,双王金矿床原生晕轴(垂)向分带序列呈明显的反带现象,ZK18-5中在标高950 m附近矿化程度最好,矿体向深部逐渐尖灭;ZK30-1在标高980 m附近矿化程度最好,其深部预测有串珠状矿体存在,深部矿化前景较好;ZK40-5在标高850 m附近矿化程度最好,预测深部矿体仍有较大规模的延伸,深部矿化前景较好。     

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