赣南寨背A型花岗岩体的地球化学特征及其构造地质意义

赣南寨背岩体主要为黑云母钾长花岗岩,黑云母结晶晚于长石和石英,锆石群型地温测量标尺显示其结晶温度为８００℃～９００℃,表明寨背岩体形成于一种高温贫水的花岗质岩浆。岩石的化学成分特点为准铝质（Ａｌ２Ｏ３为１２．２１％～１２．６２％）,富硅（ＳｉＯ２为７５．６６％～７６．７４％）,偏碱（Ｎａ２Ｏ＋Ｋ２Ｏ为７．９３％～８．９０％）,ＦｅＯＴ／ＭｇＯ值高（５９～１４８）,ＣａＯ和ＭｇＯ含量低（分别为０．１０％～０．６５％和０．０１％～０．０２％）,富含ＲＥＥ（Ｅｕ除外,ΣＲＥＥ平均为５００μｇ／ｇ）,Ｙ、Ｇａ、Ｎｂ等高场强元素（ＨＦＳＥ）以及Ｆ,Ｓｒ和Ｂａ较低。这些特点与本区的Ｉ型和Ｓ型花岗岩有明显差别,是一种典型的Ａ２型花岗岩。寨背岩体Ｒｂ－Ｓｒ等时线年龄为１７６Ｍａ,与辉长岩、双峰式火山岩有密切的时空关系,表明赣南地区在燕山早期即进入拉张裂解阶段。     

晋南中条山北峪奥长花岗岩的岩石地球化学

野外工作发现，北峪奥长花岗岩侵入于绛县群变富钾流纹岩之中，结合其２１０７±５９Ｍａ的全岩Ｒｂ－Ｓｒ等时线年龄，应为早元古代岩浆侵入的产物。北峪岩体具高的Ａｌ２Ｏ３含量和高的δ＾１８ＯＳＭＯＷ（‰）比值，表明为铝过饱和的Ｓ型花岗岩。其高的Ａｌ２Ｏ３含量和低的Ｙｂ含量及强烈分异的稀土图谱，表明形成于大陆环境。在ＬＩＬＥ元素特点上，北峪奥长花岗岩亏损Ｕ，Ｔｈ，Ｋ，Ｒｂ，具低的Ｒｂ／Ｓｒ比值和高的Ｋ／Ｒｂ     

扬子克拉通北缘新元古代岛弧花岗岩类成分极性…

对扬子克拉通北缘新古代岛弧花岗岩类成分极性的地球化学研究表明，在ＳｉＯ２含量相近的条件下，由北向南岩石中Ｋ２Ｏ、Ｋ２Ｏ＋Ｎａ２Ｏ，Ｋ２Ｏ／Ｎａ２Ｏ逐渐增加，而ＣａＯ逐渐降低；从北向南，微量元素Ｒｂ，Ｂａ，Ｔｈ，Ｚｒ，Ｎｂ，Ｔａ，ΣＲＥＥ及Ｒｂ／Ｔｈ，Ｒｂ／Ｎｂ，ΣＬＲＥＥ／ΣＨＲＥＥ（Ｌａ／Ｙｂ）Ｎ等逐渐增加或具增加趋势，而Ｓｒ，Ｃｏ，Ｎｉ和Ｓｒ／Ｂａ具逐渐降低或具降低趋势；同位素组成成由北向南δ     

青藏高原乌依塔克花岗岩体地球化学及其大地构造意义

乌依塔克花岗岩体分布于乌依塔克蛇绿岩套中,与其中的基性熔岩呈侵入接触关系,形成时代比蛇绿岩套（超）镁质岩稍晚;岩石类型为斜长花岗岩,斜长石属钠长石;岩石高ＳｉＯ２,低Ａｌ２Ｏ３,富Ｎａ２Ｏ,贫Ｋ２Ｏ（〈１％）,里特曼指数σ为０．９６￣１．０８,是钙质的;稀土元素总量较低,并且属轻稀土元素亏损型;除Ｙ含量较高外,其他微量元素含量均较低;ＩＳｒ为０．７０２５８８,εＳｒ（ｔ）为－１６．１,εＮｄ（ｔ）     

一个古元古代A型流纹岩

山西吕梁群流纹岩是一个古元古代的弱碱性火山岩,它具有高ＳｉＯ２,Ｎａ２Ｏ＋Ｋ２Ｏ和Ｚｒ,Ｇａ等高场强元素和高ＦｅＯ＾＊／ＭｇＯ,Ｒｂ／Ｓｒ和Ｇａ／Ａｌ比值,以及低ＣａＯ,Ｓｒ和Ｅｕ／Ｅｕ＾＊的地球化学特征,相似于Ａ型花岗质岩石。它形成于大陆边缘裂谷环境,化学成分及同位素特征为高εＮｄ（ｔ）值,低（＾８７Ｓｒ／＾８６Ｓｒ）ｉ值,表明流纹岩的原始岩浆由下地壳晚太古代变质岩受裂谷岩浆和热流作用的影响部分     

小秦岭303号石英脉流体包裹体Rb—Sr,^40Ar—^39Ar成矿年龄测定

用石英流体包裹体Ｒｂ－Ｓｒ、＾４０Ａｒ－＾３９Ａｒ法测定了小秦岭３０３号石英脉的形成时代为石元古代。其流体包裹体属Ｈ２Ｏ＋ＣＯ２＋ＣａＣｌ型,盐度为６．５％－１２．９８％,ＣＯ２含量高,Ｎａ＾＋〉Ｋ＋。３０３号石英脉Ｒｂ－Ｓｒ等时线年龄为（２３８２±３３６）Ｍａ－（２２３４±４７）Ｍａ,（＾８７ｓＲ／＾８６Ｓｒ）ｉ为（０．７３５１±０．００１９）－（０．７４１６±０．０００４）,＾４０Ａｒ＾＾３９     

滇西南那邦变质基性岩地球化学与俯冲板片裂离

中缅边界那邦麻粒岩相变质基性岩地球化学特征表明其原岩是岩浆岩,并具有ＭＯＲＢ的特性,其岩石化学具有以下特征：岩石的ＴＦｅ／ＭｇＯ值低（１．１０～２．１７）,ＡＦＭ图解上显示拉斑玄武岩演化趋势;ＴｉＯ２含量（１．１４％～１．８１％）高稀土亏损、重稀土较有富集的配分形式,稀土元素和总量（∑ＲＥＥ）值十倍于球粒陨石（２４～５０μｇ／ｇ）,（Ｌａ／Ｓｍ）Ｎ＝０．４３～０．７５（Ｌａ／Ｙｂ）Ｎ＝０．４５～０     

武当地块基性岩墙群及耀岭河群基性火山岩的Sr,Nd,Pb,O同位素研究

武当地块基性岩墙群与耀岭河群基性火山岩的Ｓｒ、Ｎｄ、Ｐｂ同位素特征反映它们具相同的混合地幔源区。前者的（＾８７Ｓｒ／＾８６Ｓｒ）ｉ＝０．６９０５￣０．７０６１,εＮｄ（ｔ）＝－１．９￣５．０,Δ＾２０８Ｐｂ／＾２０４Ｐｂ＝３５．４９￣１９０．２６,Δ＾２０７Ｐｂ／＾２０４Ｐｂ＝４￣８５,Ｔｈ／Ｔａ低,Ｌａ／Ｙｂ变化大;后者的（＾８７Ｓｒ／＾８６Ｓｒ）ｉ＝０．６４８７￣０．７０７５,εＮｄ（ｔ）＝０     

青藏高原西部喜马拉雅期花岗岩类特征及岩石系列

青藏高原西部喜马拉雅期花岗岩类岩石组合为透辉石正长岩－透辉石花岗岩－黑云母（二长）花岗岩,主要造岩矿物有钾长石、斜长石、石英、黑云母、透辉石和角闪石。岩石化学成分富碱、高钾、Ｋ２Ｏ／Ｎａ２Ｏ比值大,微量元素富集Ｒｂ,Ｓｒ、Ｂａ、Ｔｈ、Ｕ和ＬＲＥＥ,Ｓｒ、Ｎｄ同位素组成具有幔源特征,岩石属于钾玄岩（ｓｈｏｓｈｏｎｉｔｅ）系列。     

冀北燕山期三个系列花岗质岩石的地球化学特征及其成因学意义

燕山期花岗质岩石广泛出露在冀北地区,从中可以识别出碱钙性、过铝质和碱质三个岩石系列。本文系统报道了它们的产状、岩类学、主要元素、痕量元素、稀土元素、年代学和ＩＳｒ资料;重点讨论了它们的地球化学特征和成因类型问题。碱钙性岩石系列主要由石英二长闪长岩元素、二长花岗岩元素、正长花岗岩构成;ＳｉＯ２含量变化范围是６２％～７５％;Ｋ２Ｏ＋Ｎａ２Ｏ在７．６３％～８．８８％之间;Ａ／ＣＮＫ＜１．０５,ＣＡ指数５５。过铝质系列由流纹斑岩为代表,具有高硅（ＳｉＯ２＞７３％）、富钾低钠（Ｋ２Ｏ／Ｎａ２Ｏ为１．４４～９．１３）、过铝质（Ａ／ＣＮＫ是１．１７～１．４３）的特点。碱性系列的岩石组合是碱长正长岩（碱长粗面岩）－碱性石英正长岩（碱流岩）－碱性花岗岩（碱性流纹质熔结凝灰岩）。它们的ＳｉＯ２含量变化于５７％～７７％之间,Ｋ２Ｏ＋Ｎａ２Ｏ、Ｋ２Ｏ、Ｎａ２Ｏ分别大于９％、４％、５％,ＮＫ／Ａ为０．９～１．１２。以过铝质、碱钙性和碱性为序,三个岩石系列的Ｎｂ、Ｔａ、Ｚｒ、Ｈｆ、ＲＥＥ含量依序增高,显示出明显的区别。上述特征表明,三个岩石系列的性质和特征明显不同,分别属于三种岩石成因类型。     

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