西天山菁布拉克岩带基性－超基性岩的Nd、Sr同位素地球化学

新疆西天山菁布拉克岩带基性－超基性岩的全岩εＮｄ（ｔ）约为－５．１－＋６．４，８７Ｓｒ／８６Ｓｒ（ｔ）约为０．７０３７－０．７０９４。幔源岩浆同化围岩和结晶分异联合作用（即ＡＦＣ过程）可以解释这些岩石的Ｎｄ、Ｓｒ同位素组成。     

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     

福建省花岗岩类Nd-Sr同位素特征及其意义

本文报道了福建省范围内前人分析数据稀疏或空白区域内的１８个古生代－中生代花岗岩体的Ｎｄ、Ｓｒ同位素组成：εＮｄ（ｔ）＝－３．６～－１６．４,（８７Ｓｒ／８６Ｓｒ）ｉ＝０．７０５５～０．７３１８,ｔＤＭ＝１．２～２．３Ｇａ。结合前人分析数据,区分出三个地域区带：福安－南靖断裂以东的沿海带：εＮｄ（ｔ）＝－１．５～－６．８,（８７Ｓｒ／８６Ｓｒ）ｉ＝０．７０５６～０．７０９９,ｔＤＭ＝１．１～１．４５Ｇａ,弧后伸展构造背景下的幔－壳岩浆混合是该带花岗岩的主要成岩方式;福安－南靖断裂以西的内陆区域：εＮｄ（ｔ）＝－４．０～－１６．４,（８７Ｓｒ／８６Ｓｒ）ｉ＝０．７０６４～０．７４１０,ｔＤＭ＝１．３～２．３,其中加里东－印支期花岗岩主要由与麻源群相当之地壳物质部分熔融形成,而燕山期花岗岩,一部分由与麻源群相当或较年轻的地壳物质部分熔融产生,也有一部分可能由壳－幔岩浆混合形成;福建省南部的纬向带：εＮｄ（ｔ）＝－３．６～－７．５,（８７Ｓｒ／８６Ｓｒ）ｉ＝０．７０５５～０．７０９９,ｔＤＭ＝１．２～１．５５,同位素特征与沿海带相似,但该带构造拉张发育时间较沿海带略早     

加拿大苏必利尔区太古宙煌斑岩脉的成因：微量元素和Nd—Sr同位…

出露于加拿大苏必利尔罗灵河杂岩体中的含角闪石斑晶和单斜辉石斑晶的煌斑岩，具有碱性，含霞石标准矿物的玄武岩质成分（ＳｉＯ２＜５０ｗｔ％），成分变化从原始岩浆到分异岩浆［Ｍｇ／Ｍｇ＋∑Ｆｅ）＝０．６６－０．４０；Ｎｉ＝２００－３５ｐｐｍ］，岩石富含ＬＲＥＥ［Ｃｅ／Ｙｂ）ｍ＝１６－２６，Ｃｅｎ＝６０－３００；ｎ＝球粒陨石标准化］，Ｓｒ（８７０－１８００ｐｐｍ），Ｐ２Ｏ５（０．４－１．３ｗｔ％）和Ｂａ（１     

西天山前寒武纪天窗花岗片麻岩的锆石U—Pb年龄及Nd—Sr同位素特征

采用颗粒级锆石Ｕ－Ｐｂ定年方法,精确测定了西天山前寒武纪天窗花岗片麻岩的结晶锆石年龄为７９８Ｍａ,它代表了花岗质岩浆的结晶时代。花岗片麻岩具有较高的ＩＡＳ值（１．１７￣１．５５）和ＬＩＬＥ、ＬＲＥＥ含量,明显的Ｅｕ负异常（δＥｕ＝０．２４－０．３８）和Ｂａ、Ｓｒ、ｐ、Ｔｉ、Ｎｂ、Ｔａ的亏损,表明源岩为成熟度很高的陆壳物质。其负的εＮｄ（ｔ）值（－４．４￣－６．４）和较高的初始＾８７Ｓｒ／＾８６Ｓｒ     

冀西北水泉沟正长岩杂岩体的成因

水泉沟碱性正长岩杂岩体侵入于太古宇桑干群变质岩中，岩体主要由碱性长石正长岩、角闪碱长正长岩、正长岩、石英碱长正长岩等组成，属碱性岩系列，在岩石的石英颗粒中见有熔融包体的存在。岩石的稀土元素分布模式呈平滑的右倾模式，无明显的铕异常。岩石的Ｐｂ同位素组成为２０６Ｐｂ／２０４Ｐｂ＝１６．４５７～１８．２８６、２０７Ｐｂ／２０４Ｐｂ＝１５．２７０～１５．４７２、２０８Ｐｂ／２０４Ｐｂ＝３６．５３９～３７．３９３，石英的δ１８Ｏ值为８．０‰～８．５‰，（８７Ｓｒ／８６Ｓｒ）ｉ≈０．７０５，岩石的ｔＤＭ为１．６～１．９Ｇａ，εＮｄ（ｔ）为－７．４５～－１３．１，明显大于区域基底的εＮｄ（ｔ）值（－２０±）。以上结果表明，岩体为上地幔和下地壳物质部分熔融的产物。岩体角闪石３９Ａｒ－４０Ａｒ年龄３２７Ｍａ，为海西期岩浆作用的产物     

新疆阿尔曼太蛇绿岩时代的Nd—Sr同位素地质研究

本文通过测定采自新疆阿尔曼太兔子泉一带蛇绿岩的堆晶辉长岩、辉绿岩和安山玢岩，获得Ｓｍ－Ｎｄ等时年龄为５６１±４１Ｍａ，εＮｄ（ｔ）＝６．１，Ｒｂ－Ｓｒ等时年龄为３９２±１７Ｍａ，（８７Ｓｒ／８６Ｓｒ）ｉ＝０．７０４１，前者为蛇绿岩的形成时代，后者为蛇绿岩遭受后期变质作用的时间。札河坝－阿尔曼太蛇绿岩的形成环境可能是古亚洲洋向南俯冲引起的弧后盆地     

郭家岭花岗岩的时代与成因

与前人的划分不同，本所指的郭家岭花岗岩只包括郭家岭和丛家两个岩体。由郭家岭岩体的５个全岩样品给出的Ｒｂ－Ｓｒ等时线年龄为２００．６±３．４８Ｍａ，（＾８７Ｓｒ／＾８６Ｓｒ）ｉ＝０．７１１２７、Ｒ＝０．９９９５５，表明该岩体支运动末期形成的。常量元素、微量元素及稀土元素表明该花岗岩是由壳幔物质混合形成的。     

山东蓬莱,临朐新生代碱性玄武岩的钕,锶同位素组成

本文报道了鲁东和鲁西新生代碱性玄武岩１３个样品的Ｎｄ，Ｓｒ同位素组成，１４３Ｎｄ／１４４Ｎｄ＝０．５１２９６７－０．５１２７４４，８７Ｓｒ／８６Ｓｒ＝０．７０３４９－０．７０４５０。它们在地质剖面上呈现规律性变化，可能与其地幔源区同位素组成的层状分带有关。鲁西地幔源区具有较鲁东更加亏损的组份。两地地幔源区在演化中都曾发生过地幔交代（或富集）作用，根据玄武岩Ｎｄ同位素模式年龄估计地幔交代作用发生的时     

对桐庐早白垩世火山—侵入岩成因的几点认识

本文报导了对桐庐火山－侵入岩进一步研究所获得的认识。单颗锆石Ｕ－Ｐｂ年龄测定表明桐庐火山－侵入岩是早白垩世火山活动的产物（１３４．４～１３４．９Ｍａ）。浅部岩浆房中从上往下的流纹质、流纹英安质和石英闪长质岩浆具有相近似的Ｒｂ－Ｓｒ和Ｓｍ－Ｎｄ同位素初始比,（８７Ｓｒ／８６Ｓｒ）ｉ＝０．７０８～０．７０９、εＮｄ（ｔ）＝－５．２７～－６．５６,高场强元素比（如Ｚｒ／Ｎｂ＝１０．１～１３．１）也相近似,表明盆地中各种火山－侵入杂岩是同源的。流纹英安岩中钾长石碎斑周围“组分过冷边”的存在说明岩穹壳内部酸性岩浆的冷凝、结晶要比酸性熔岩流来得慢。盆地中心浅成侵入岩中的中性岩包体的Ｒｂ－Ｓｒ和Ｓｍ－Ｎｄ同位素成分、Ｍｇ／（Ｍｇ＋Ｆｅ）以及Ｎａ／（Ｎａ＋Ｃａ）比表明它们是岩浆房下部石英闪长质岩浆的岩浆熔离作用产物     

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