山西中条山地区北峪奥长花岗岩的同位素年龄和同位素地球化学特征

追索北峪奥长花岗岩与围岩接触关系，发现北峪奥长花岗岩已侵入于围地层中，表明其为早元古代岩浆型侵入体。使用全岩Ｒｂ－Ｓｒ等时线方法测定北峪奥长花岗岩时代，获得的年龄为２１０７±５９Ｍａ（２σ），由此推断北峪岩体成岩时代为２１００Ｍａ，代表了本区绛县运动岩浆成事件年龄。     

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     

吉林南部太古代花岗岩Sm—Nd,Rb—Sr同位素年龄测定

吉林南部太古代花岗质岩石经同位素年龄测定，英云闪长质片麻岩类的Ｒｂ－Ｓｒ全岩等时年龄为２４１７±１２１Ｍａ，Ｓｍ－Ｎｄ全岩等时年龄为２４１６±１２７Ｍａ，模式年龄为２８４０Ｍａ；辉石花岗岩类的Ｒｂ－Ｓｒ全岩等时年龄为２３４６±２３２Ｍａ，Ｓｍ－Ｎｄ全岩等时年龄为２４４０±１５９Ｍａ，模式年龄为２７８０Ｍａ。反映这些岩石都是在太古宙晚期形成的，并且是在较短的时间间隔内完成的，其模式年龄与华北地台太古宙主体地壳的形成时代一致。     

阿尔泰地区中、新生代岩浆活动的同位素年龄证据

长期以来，对阿尔泰地区有无印支、燕山期岩浆活动一直存在争议。本研究得到以下年龄结果：将军山花岗岩（＾４０Ａｒ／＾３９Ａｒ坪年龄）２２０Ｍａ、康布铁堡花岗岩（＾４０Ａｒ／＾３９Ａｒ高温视年龄）２１４Ｍａ、尚可兰花岗岩（Ｒｂ－Ｓｒ全岩等时线年龄）１７６Ｍａ、阿拉尔花岗岩（＾４０Ａｒ／＾３９Ａｒ坪年龄）１３１Ｍａ。以上数据和与本区处在同一构造单元的前苏联矿区阿尔泰及山区阿尔泰１２个浅色花岗岩锆石Ｕ－Ｐｂ     

浙西南早元古代花岗质岩石的年代

用单颗粒锆石Ｕ－Ｐｂ稀释法获得的浙西南前寒武纪变质基底中花岗质岩石的年龄为：下际二长花岗岩１９７５±８０Ｍａ，里庄二长花岗岩１８７０±３６Ｍａ，田后花岗闪长岩１８３２±８０Ｍａ，三枝树混合岩１９６３±４４Ｍａ。这些年龄数据证实本区基底岩石在１８７５±１００Ｍａ时期经历了一次广泛强烈的岩浆热事件，表明八都群（麻源群）岩石的形成应早于２．０Ｇａ。三枝树地区“鹤溪群”中混合岩年龄为１８６３±４４Ｍａ，斜长角闪岩全岩矿物Ｓｍ－Ｎｄ等时线年龄为２０７１±４８Ｍａ，表明景宁三枝树地区变质岩的时代应为早元古代，并非原来所属“鹤溪群”划归的晚古生代，这套变质岩可能是浙闽变质基底的一部分。     

黑龙江碾子山晶洞碱性花岗岩岩体年龄及其意义

用Ｋ－Ａｒ法和和Ｒｂ－Ｓｒ等时线法测定了碾子山晶洞碱性花岗岩的年龄，花岗岩及其围岩安山岩、正长斑岩、碱流岩、玄武岩和闪长岩脉的年龄分别为１２３、１４１、１３５、１２０、１０８和８０Ｍａ。该期碱性花岗岩的侵位反映了大兴安岭南部早白垩世以形成拗陷盆地为物质特征的构造岩浆活动。碱性花岗岩与其主要围岩构成了同一Ｒｂ－Ｓｒ等时线，表明它们是同源的；Ｓｒ同位素初始值和其他同位素证据表明它们是由上地幔来源的母岩     

北秦岭晚古生代—中生代花岗岩类的Nd.Sr.Pb同位素地球化学特征及Nd.Sr

北秦岭晚古生代—晚中生代花岗岩类的Ｎｄ，Ｓｒ同位素研究表明：具低放射成因Ｐｂ同位素组成的花岗质岩基主要是南秦岭基底变质岩深熔的产物；而具高放射成因Ｐｂ同位素组成的原地、半原地型花岗岩类是北秦岭丹凤群有关岩石深熔和交代作用形成的产物．它们都可分为Ｉ型和Ｓ型，并可同时共存，岩浆源区中都有基性岩石物质的加入，其区别是基性岩类物质对Ｉ型花岗岩类的贡献分数较大，具有较小的亏损地幔模式年龄；由于岩浆源区中不同物质组成的混合，花岗岩类的亏损地幔模式年龄并不代表真实的壳幔分异事件的年龄．从新元古代到晚中生代，Ｉ型花岗岩类的ｄ（ｔ）和ＴＤＭ具逐渐变小的趋势，反映了地壳中基性岩石物质发生深熔作用的时间逐渐变晚，而Ｓ型花岗岩类的ｄ（ｔ）增大，ＴＤＭ变小，反映了基性岩石物质加入比例的增大，暗示着碰撞作用阶段具更加强烈的岩浆作用     

北秦岭东段峡河岩群中斜长角闪岩Sm－Nd同位素年龄

北秦岭造山带东段的牌楼沟地区，峡河岩群中的斜长角闪岩（原岩为基性火山岩）测得全岩Ｓｍ－Ｎｄ同位素等时线年龄为１６０５±７６Ｍａ，钛同位素初始比值为εＮｄ（Ｔ）＝＋５．３，表明峡河岩群变质岩系形成于中元古代。斜长角闪岩来源于亏损的地幔源区。上述测定结果，为阐明北秦岭造山带在中元古代时期的构造演化提供了佐证。     

祁连山金佛寺岩体的岩石学和同位素年代学研究

金佛寺岩体位于北祁连山区山前断裂南侧，属加里东晚期侵入体。由金佛寺花岗闪长岩－石英二长岩、大草滩二长花岗岩及干巴口二云母花岗岩３个侵入阶段的岩体组成。前两阶段岩体的全岩Ｒｂ－Ｓｒ等时线年龄分别为４１９．８７±０．４Ｍａ和４０３．７±０．０８Ｍａ。表明其侵位时代为志留纪中晚期。岩体定位以后经历了３次抬升和两次沉降。     

扬子克拉通北缘元古宙基底同位素地质年代学和地壳增生历史：Ⅱ．火地垭群

扬子克拉通地壳的生成始于太古宙，但依据目前的研究成果，其主体形成于元古宙，对位于扬子克拉通北缘，分布在碑坝地区重要的基底岩系之一的火地垭群铁船山组火山岩进行了Ｓｍ－Ｎｄ和Ｒｂ－Ｓｒ同位素地球化学研究．同位素年代学数据表明，铁船山组岩系形成于约（１６６８５）Ｍａ的中元古代，并源于高亏损的地幔岩浆库（ｄ（ｔ）７．５３．１０），且其亏损地幔模式年龄ＴＤＭ（（１．６８±０．１０）Ｇａ）与Ｓｍ－Ｎｄ等时年龄是一致的．Ｒｂ－Ｓｒ同位素年代学揭示出在新元古代早期（约（８６０±１２）Ｍａ的晋宁期）铁船山组岩系受到了构造热事件的改造．该事件与区内大规模的基性－超基性和碱性、中－酸性岩浆活动的同时出现在时间上是一致的．这些晋宁期岩浆作用有着以下共同特征：（１）岩浆源于亏损程度大为降低的岩浆库；（２）模式年龄ＴＤＭ与铁船山组火山岩的形成时代相近．在本区的西乡地区，同为中元古代形成的西乡群底部的白勉峡组火山岩与其周围的晋宁期基性－超基性和碱性、中－酸性岩浆岩在年代学特征、岩浆库性质和亏损地幔模式年龄等多方面与碑坝地区铁船山组火山岩及其周围晋宁期岩浆岩的特征是类似的．这些同位素地球化学特征所揭示的区内地壳增生和晋宁期构造历史进一     

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