内蒙古沙锡拉特地区土壤地球化学特征及找矿方向

内蒙古沙锡拉特地区位于大兴安岭多金属成矿带中段,为明确找矿方向,对研究区进行1∶1万土壤地球化学测量。采用单元素异常、组合异常与因子分析对研究区土壤地球化学数据进行评价。单元素异常显示,Ag、Pb、Zn与Sn元素的异常规模大、强度高。组合异常圈定4个异常,分为Ag—Au—As—Sb与Bi—W—Pb—Zn—Sn两类。因子分析将所分析元素分为五组,其中F1因子由Ag—Au—As—Sb元素组成,F2因子由Pb—Zn—Sn元素组成。根据土壤地球化学异常特征与区域成矿地质条件,在本区圈定2个找矿靶区,BQ—1为Pb—Zn—Sn找矿靶区,BQ—2为Ag找矿靶区。     

青海省纳日宗地区水系沉积物地球化学特征及找矿远景

纳日宗地区位于南祁连岩浆弧和宗务隆山—夏河—甘加裂谷的接触部位,该区及其周边已发现金属矿床(点)10余处,具有良好的金、铅、铜矿找矿前景。以该区1∶5万水系沉积物测量的16种元素含量数据为基础,统计分析了水系沉积物地球化学参数、元素相关性、成矿有利度系数等指标,总结了元素组合、富集贫化规律及其与地质背景、地质构造与成矿作用的关系。区内主要富集元素为Sn、Pb、Bi、As、Sb,成矿有利度系数高的元素有As、Pb、W、Au、Bi、Sb。结果显示,水系沉积物元素异常沿NW—NWW向断裂构造分布,初步认为构造发育地段具有较好的Au、Pb、W找矿潜力。依据单元素异常特征和成矿地质条件,圈定综合异常74处,划分出3个找矿远景区,指出了各找矿远景区的找矿方向。     

河北省怀安县朱家洼矿区地球化学特征与找矿方向

河北怀安朱家洼矿区位于华北板块北缘中段太古宙、元古宙、中生代金银铅锌铁硫铁矿成矿带,为火山热液型金多金属矿。为查明该区成矿规律,明确找矿方向,在区内开展了水系沉积物测量、土壤地球化学测量等工作。通过对元素分布、元素相关性、元素异常等特征研究表明,Au、Mo为本区主成矿元素;各元素异常平面分布具有分带性,高温元素W、Sn、Bi异常位于骆驼山火山机构中心,中低温元素Pb、Zn、As、Ag等异常分布于火山机构边部及周边围岩中,成矿元素Au、Mo异常主要位于火山机构西侧围岩中。异常查证发现金钼矿化体2条,金钼矿化受火山机构和北西向构造带控制。依据成矿地质条件、地球化学异常及查证成果认为,朱家洼矿区Au、Mo成矿潜力大,火山机构西侧围岩区是该区重点找矿地段。     

赣东北资溪县架上钨钼普查区土壤地球化学异常特征及其找矿预测

架上钨钼普查区位于赣东北地区,区域上具有良好的钨钼矿成矿地质条件。为了分析矿区成矿地质及地球化学条件,根据1∶1万土壤地球化学测量结果,运用相关分析和因子分析等方法,显示W、Mo、Bi、Cu、Ag元素相对富集成矿的可能性较高,通过迭代方法,计算10种元素的背景值和异常下限值,共圈定单元素异常219个,其中Au异常12个,Ag异常30个,Mo异常12个,Cu异常25个,Pb异常35个,Zn异常23个,W异常20个,Sn异常20个,Bi异常22个,As异常20个。结合成矿地质条件及各元素异常特征,圈出找矿靶区2处,其中Ⅰ级靶区1处(Ⅰ甲),Ⅱ级靶区1处(Ⅱ甲)。     

云南李子坪锡多金属矿区地球化学特征及找矿预测

工作区在区域地球化学上属滇东南Sn、W、Ag、Au多金属地球化学区的南东端老君山Sn、Zn、Ag、W、Sb多金属地球化学分区。元素的化探异常分布与花岗岩和深变质岩系(花岗片麻岩、片麻岩、片岩类)分布规律基本一致,为Sn、W、Bi、U、Th、Be等元素高含量区,Li、B、Sr、Nb、Ta、Ag、As、Cu、Zn、Pb、Cd、Mo、F、Au等元素部分高含量区。土壤地球化学测量中采用一种非正规网度,系统研究土壤中化探元素富集规律,总结其与基岩及矿化体的联系。通过运用化探找矿方法,发现化探异常并进行查证,优选了重要异常,确定找矿靶区;结合已知锡多金属矿化体部位,开展地质地球化学剖面测量,圈定甲1类异常AP-3异常1个,经深部钻探工程验证,初步确定为一中型锡多金属矿床。     

土壤地球化学测量在汝城县蕴坪矿区的找矿应用

总结了湖南汝城县蕴坪矿区的地质特征,并对该区1∶1万土壤地球化学测量元素含量特征及元素组合特征进行了研究,认为该区Ag、Pb、Zn、W、Sn、Mo、Bi等地球化学异常显示明显,其中Pb、Zn、W为矿区主成矿元素。Ag、Pb、Zn、W、Sn、Mo、Bi异常强度大、分带好、浓集中心和峰值明显,异常范围受区内断裂构造破碎带、棋梓桥地层等控制。在矿区内圈定出YP1～YP3三个预测靶区,通过槽探及钻探工程验证于YP1和YP2内发现了Pb-Zn-1号铅锌矿体,在YP3内发现了Pb-Zn-2号铅锌矿体。结合矿区地质成矿条件和土壤地球化学异常特征,初步总结了蕴坪矿区铅锌矿找矿标志,为该区进一步找矿提供了指导。     

滇西北香格里拉翁水地区水系沉积物地球化学特征及找矿预测

翁水地区位于滇西北义敦岛弧南段,属于香格里拉弧斑岩型Cu-Mo-W成矿带,区内已发现大型休瓦促Mo-W矿床及多处金属矿床(点),具寻找Mo、 W、 Pb和Zn等多金属矿前景。1∶50 000水系沉积物地球化学测量成果显示,翁水地区Cu、 W、 Pb、 Zn、 Sn、 As、 Sb、 Bi、 Co和Ni等元素丰度显著高于西南三江成矿带水系沉积物背景值;元素异常明显受控于构造和岩性,Au元素主要富集在喇嘛亚组三段(T₃lm³);W、Mo和Bi元素主要富集在二长花岗岩;Pb, Zn元素主要富集在图姆沟组二段(T₃t²)。综合研究区元素异常特征、成矿地质条件及异常查证结果,圈定29处地球化学综合异常,优选2处找矿预测区,即休瓦促Mo-W A级找矿预测区和磨莫亚Pb-Zn-Ag B级找矿预测区,为进一步找矿工作提供了勘查方向和重要参考。     

藏东达翁金矿区土壤地球化学特征与找矿潜力研究

藏东达翁金矿区位于班公湖-怒江成矿带东段,其成矿地质背景和成矿地质条件优越。为研究该矿区找矿潜力,利用SPSS软件对1∶10000土壤地球化学测量获得的Au、Ag、Cu、Pb、Zn、As、Sb、Mo、W、Bi等10种元素数据进行多元统计分析,运用元素异常NAP值累加方法和组合元素NAP值异常评序方法分别对各元素的成矿潜力及综合异常的找矿潜力进行评价。结果表明：区内矿化与中酸性岩浆热液有关,Pb、As、Sb、Ag、Bi是矿化体前缘晕指示元素,Au是主成矿元素,W是近矿指示元素,Cu、Mo是矿化体尾晕指示元素;Au的成矿潜力最大,Bi、Mo成矿潜力较大,Sb、Ag有一定的成矿潜力;区内共圈定土壤地球化学综合异常5个,其中HS-1综合异常找矿潜力最大,其次是HS-4综合异常。结合成矿地质特征和异常查证结果认为,区内具有寻找隐爆角砾岩型金矿、斑岩型钼金矿的巨大潜力及热液型银锑铋多金属矿的较大潜力。     

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。     

半荒漠戈壁地区土壤地球化学找矿研究——以阿拉善右旗塔布格地区为例

内蒙古阿拉善塔布格地区主要地貌形态为荒漠、戈壁和山地,本文基于1∶1万土壤地球化学测量工作成果,系统总结了塔布格地区地质特征,并对研究区内元素含量、异常组合和土壤地球化学异常等特征进行研究,结果表明:Au、Ag、Pb异常强度高、规模大,具有明显的浓集中心和浓度分带,多元素异常套合好,且与地质构造对应,异常查证发现含金石英脉,Au、Ag、Pb为主要成矿元素,As、Sb、Bi、Hg、Sn、Cu、Mo、Zn、W为成矿指示元素。综合地质成矿背景及化探异常特征,在区内圈定两处以金为主的多金属找矿靶区,认为后续工作主攻矿种应为金,主攻矿化类型为与韧-脆性构造变形有关的构造热液型金多金属矿化。     

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