康滇地轴东缘铅锌矿床铅硫同位素地球化学研究

康滇地轴东缘不同时代碳酸盐地层中铅锌矿床的铅同位素研究表明,其＾２０７Ｐｂ／＾２０４Ｐｂ与＾２０８Ｐｂ／＾２０４Ｐｂ呈良好线性关系,＾２０７Ｐｂ／＾２０６Ｐｂ和＾２０８Ｐｂ／＾２０６Ｐｂ为一常数。结合对本区床的稀土元素及成矿流体地球化学的研究,判定不同层位铅锌矿床是在同一个成矿体系同时形成的,一次成矿,其成矿年龄为２４５Ｍａ;同时说明不同矿床成矿金属有相同的来源,主要来自上地幔。成矿硫以来自地层中     

我国矽卡岩型铜矿床同位素地质特征及其“三位一体”成矿模式

总结了典型折矽卡岩型铜矿床同位素地质地球化学特征，认为我国矽卡岩型铜矿床成矿岩体（＾８７Ｓｒ／＾８６Ｓｒ）ｉ一般在０．７０６￣０．７１０变化，岩体为幔壳混合源型。矿石铅同位素组成均匀、稳定，特别是铀铅，＾２０６Ｐｂ／＾２０４Ｐｂ＝１７．０７５￣１８．１００，＾２０７Ｐｂ／＾２０４Ｐｂ＝１５．３３７￣１５．６３５，比值变化小，而＾２０８Ｐｂ／＾２０４Ｐｂ比值变化稍大，矿石铅源主要来自成矿岩体。矿石δ     

论“华夏古大陆”—铅同位素研究证据

我国东南部地区一批中生代花岗岩类岩石中长石铅同位素数据表明,至少可将该地区地壳基底岩石划分三大块体。一是武夷块体,其范围包括江－绍断裂带以南,赣江－河源断裂以东和政和一大埔断裂中,南段以西地区,它们的中生代花岗岩长石铅同位素＾２０６Ｐｂ／＾２０４Ｐｂ,＾２０７Ｐｂ／＾２０４Ｐｂ和＾２０４Ｐｂ／＾２０４Ｐｂ三组比值平均分别为１８．２２６;１５．６２０和３８．７２５;另一块体为闽台块体,即政和一大埔断     

大厂锡石多金属硫化物矿床铅同位素演化及其矿床成因的意义

大厂锡石多金属硫化物矿床由两类４形矿化组成,一类为层状及似层状矿化：另一类为不规则脉状矿化,包括大脉状,细网脉状和囊状３种不同形态的矿化。这两类矿化在铅同位素的组成上有比较明显的差异,而相同形态的矿化之间大致相同。层状矿化＾２０７Ｐｂ／＾２０４Ｐｂ和＾２０６Ｐｂ／＾２０４Ｐｂ的比值较低,在同位素比值图上的数据点比较分散,且放射性同位素的含量随生成时代的变断而呈现规律性的增加。     

大别山北缘中生代火山—侵入岩铅同位素组成特征及其地质意义

大别山北缘中生代火山－侵入岩的１４个夺铅同位素组成表现为高的非放射性成因＾２０４Ｐｂ,较低的＾２０６Ｐｂ／＾２０４Ｐｂ比值和低且相对一致的＾２０７Ｐｂ／＾２０４Ｐｂ比值,属于明显的低Ｕ／Ｐｂ体系,并暗示它们由具低μ值的源岩衍生的。     

东坪式金矿床铅同位素组成特征及其化探评价

东坪式金矿床产于华北克拉通化缘深大断裂－－尚义－赤城断裂的南侧,海西期水泉沟正长岩杂岩体内外接触带。矿体具有明显的分层笥,自上而下矿石类型由石英脉型向钾、硅化蚀变岩型过渡。矿床形成于燕山早期,成矿物质主要来源于正长岩杂岩体。矿石铅同位素组成与正长岩杂岩体相似,在＾２０７Ｐｂ／＾２０６Ｐｂ－＾２０８Ｐｂ／＾２０６Ｐｂ图解上,矿石、正长岩、矿石中的钾长石脉石及太古宇桑干群变质岩呈线性分布,矿石与正长岩     

粤西大沟谷钠长石岩型金矿床成矿物质来源研究

粤西大沟谷钠长石岩型金矿床主要产于震旦系乐昌峡群呈似层状及脉状分布的钠长石岩中，钠长石岩的岩石化学成分及微量元素组成与金矿体的基本相同。黄铁矿Ｐｂ、Ｓ同位素组成可分为两组：富放射性成因铅贫＾３４Ｓ体系；贫放射性成因铅富＾３４Ｓ体系，前者与震旦系片岩的组成相似，后者为自较老富基性岩的沉积岩。     

南天山托云盆地晚白垩世——早第三纪玄武岩的地球化学特征 …

托云盆地晚白垩世－－早第三纪碱性橄榄玄武岩Ｓｒ、Ｎｄ、Ｐｂ同位素组成表明,本区玄武岩以低Ｓｒ、Ｐｂ和相对高的Ｎｄ同位素值（＾８７Ｓｒ／＾８６Ｓｒ为０．７０３５５４￣０．７０３８８４;＾１４３Ｎｄ／＾１４４Ｎｄ为０．５１２８３８￣０．５１２９０４;＾２０６Ｐｂ／＾２０４Ｐｂ为１８．００６３￣１８．４７２０;＾２０７Ｐｂ／＾２０４Ｐｂ为１５．４４１１￣１５．５０６０;＾２０８Ｐｂ／＾２０４Ｐｂ为３７．     

南秦岭东江口岩体群Pb,Sr和Nd同位素地球化学特征及其对物源的制约

以区域地球化学研究成果为基础,通过Ｐｂ、Ｓｒ、Ｎｄ同位素特征分析,揭示出东江口岩体群的Ｐｂ同位素特征与南泰岭东段基底具有耦合关系,而与其它构造单元则存在明显的差异,＾２０４Ｐｂ－＾２０７Ｐｂ／＾２０６Ｐｂ,＾２０４Ｐｂ－＾２０８Ｐｂ／＾２０６Ｐｂ图解研究表明,该岩体群为下地壳源花岗岩类,Ｎｄ同位素特征（ｔＤＮ和εＮｄ（ｔ）表明,耀岭河群最适合于作为岩体群的主要物源。该岩体群和耀岭河群的Ｓｒ同位素存     

赤峰红花沟金矿田铅同位素组成特征及其成因意义

内蒙赤峰红花沟金矿田矿石铅的２０６Ｐｂ／２０４Ｐｂ范围为１５．４７—１６．４９,２０７Ｐｂ／２０４Ｐｂ为１４．６６—１５．８９,２０８Ｐｂ／２０４Ｐｂ为３５．９２—３８．４８。在铅同位素演化图中呈线性排列,反映出两端元的混合,即古老的基底岩石铅与古老的多阶段演化铅的混合。中－新生代岩浆岩和太古代片麻岩等岩石铅的２０６Ｐｂ／２０４Ｐｂ为１７．３—１８．１,２０７Ｐｂ／２０４Ｐｂ为１５．４—１５．７,２０８Ｐｂ／２０４Ｐｂ为３７．２—３８．２,与矿石铅明显不同,表明矿石铅来源与上述岩石无关。而含透辉石斜长角闪岩的铅同位素组成与矿石铅范围一致或接近,两者间可能有成因联系。矿石铅可能主要来源于太古代基底绿岩建造之含透辉石斜长角闪岩。     

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