南秦岭元古宙板内火山作用特征及构造意义

南秦岭元古宙火山岩主要由两大类岩石构成，一类为SiO245%-57%的基性火山岩系，另一类为SiO267%-78%的酸性火山岩系，主要岩石类型为细碧岩、玄武岩和石英角班岩、流纹岩。基性火山岩整体上属拉斑玄武岩系列，酸性火山岩属钙碱系列。火山岩强烈富集稀土元素，尤其是轻稀土元素，酸性火山岩和基性火山岩有相似的稀土元素特征，显示了源区特征的不同。基性火山岩富集强不相容元素，相对亏损Nb和Ti, 成于大陆裂谷环境，具有大陆拉斑玄武岩的特征。同位素特征表明基性火山作用与地幔柱活动密切相关。南秦岭的中、晚元古代大陆拉张及由古地幔柱活动所引发的陆裂火山岩浆活动是古秦岭洋打开的先兆。     

甘肃南祁连党河南山奥陶纪火山岩的岩石地球化学特征

甘肃南祁连褶皱带党河南山早奥陶纪火山岩主要赋存于吾力沟群中。地球化学研究结果表明,本区火山岩由基性火山岩和中性火山岩组成,基性火山岩分属拉斑玄武岩和钙碱性玄武岩,而中性火山岩则属钙碱性安山岩。它们均具有低TiO2、MgO,选择性富集大离子亲石元素(Rb、Th、Ba、Sr)和轻稀土元素(La、Ce、Sm),具有较高的高价大阳离子比值和Nb的强烈亏损,岩石学和地球化学特征表明本区火山岩形成于岛弧环境。     

祁漫塔格地区十字沟蛇绿岩地质特征

十字沟蛇绿岩产出于东昆仑西段祁漫塔格结合带东部,主要由蛇纹岩、辉长岩、辉绿岩、基性火山岩及硅质岩等组成。其中,从超基性岩—基性岩—基性火山岩,具稀土总量逐渐增加,轻稀土弱亏损型特征,基性火山岩为洋脊玄武岩,总体岩石化学成分与大洋中脊低钾拉斑玄武岩相当,三者的配分型式基本一致,说明其继承了源区地幔的特征,微量元素显示基性火山岩具弧后盆地玄武岩特点。Nεd(t)比值表明玄武岩来自亏损地幔源区,总体地球化学特征显示以N-M ORB型为主,兼具有E-M ORB型的特征,形成于与俯冲作用有关的弧后盆地环境,形成时代为晚奥陶世。后期至少经历了3期以上构造变形变质作用的叠加改造,于早志留世运移至地表。     

纸房地区早奥陶世海相火山岩岩石化学特征

纸房地区具有早奥陶世海相火山岩存在。火山岩层中以溢流相的中基性火山岩为主 ,局部地段比较发育以酸性岩类为主的次火山岩 ,中基性火山岩的岩石化学类型属于拉斑玄武岩钠质类型。岩石化学特征表明火山岩形成于洋岛构造环境     

辽河群含硼岩系基性火山岩地球化学特征及形成环境

以往研究认为辽东古元古界地层中存在基性火山岩和中酸性火山岩组成的双峰式火山岩,并以此作为辽吉大陆裂谷的重要证据。本文重点讨论了辽河群含硼岩系中基性火山岩的地球化学特征,结果表明,这些基性火山岩原岩为玄武岩,属高钾—中钾玄武岩,具有拉斑玄武岩和碱性玄武岩双重特征。主量元素表现为富钠、低硅、高铁的特征。稀土元素配分曲线主要显示平坦型曲线,与大洋环境下形成的正角闪岩具有较为相似的稀土元素分布模式。辽河群含硼岩系中基性火山岩原岩的形成环境为大洋环境。     

辽东地区早元古代火山岩特征及其形成的动力学背景

辽东地区早元古代火山岩是下元古界辽河群地层的重要组成部分,它们由酸性和基性两套火山岩组成。前者形成于辽河裂谷发育早期的拉张裂陷阶段,属于壳源岩浆成因;后者形成于辽河裂谷发育中晚期的强烈拉张裂陷阶段,属于幔源岩浆成因。重点讨论了基性火山岩的岩石学、矿物学、岩石化学和地球化学特征,结果表明,这些基性火山岩主要为一套海底喷发的基性枕状熔岩,具有大陆拉斑玄武岩和大洋拉斑玄武岩的双重特征,是辽河裂谷由大陆壳向大洋壳演化过程中的产物。火山岩形成的动力学背景与早元古代时期热地幔对流形式的出现以及郯-庐断裂带发生右旋平移剪切活动密切相关。     

白松—奔都地区晚三叠世义敦岛弧带火山岩岩石地球化学特征及成因

白松—奔都地区义敦岛弧带火山岩,系三叠系上统曲嘎寺组和图姆沟组一套基—酸性火山岩。其中曲嘎寺组火山岩为玄武岩、玄武安山岩组合;图姆沟组火山岩为玄武安山岩、流纹岩组合。流纹岩中可见黄铁矿化和铜、铅、锌等矿化。曲嘎寺组玄武岩属大洋拉斑玄武岩(OT),图姆沟组玄武岩属大陆拉斑玄武岩(CT)。     

闽北早古生代岛弧火山岩的岩石地球化学特征

作者系统地研究了福建政和早古生代岛弧火山岩的岩石地球化学特征。研究表明该火山岩是以岛弧拉斑玄武岩-钙碱性火山岩组合为特征的岛弧火山岩系列，并具有从拉斑系列向钙碱性系列演化的特征；该火山岩源于亏损地幔，并且受到一定的陆壳物质混染，基性的拉斑玄武质系列受到陆壳物质混染较少，而中性钙碱性系列则受到较大程度混染。     

南秦岭元古宙西乡群大陆溢流玄武岩的确定及其地质意义

中元古代西乡群火山岩是南秦岭元古宙最老的火山岩系，以其大面积分布，具浅海－陆相火山岩组合，属大陆拉斑玄武岩系列，具大陆板内火岩岩地球化学特征及与大的基性侵入体共生等特点、可确认其属大陆溢流玄武岩系。     

西秦岭丹凤群变质火山岩的地质地球化学特征及其成矿环境初探

位于西秦岭褶断带的甘肃省两当县太阳寺一带金及多金属矿床的规模已达大型。丹凤群是该矿床的重要的含金、银、铅岩系。其火山岩以基性玄武岩为主,另有部分中性安山岩及少量的酸性流纹岩,具有从基性-中性-酸性的岛弧火山岩的演化模式。变玄武岩表现出岛弧拉斑玄武岩特有的富Al^₂O₃、贫TiO₂的特征。构造环境图解表明,这些玄武岩多为岛弧拉斑玄武岩,微量元素特征与Condie1982年给出的岛弧拉斑玄武岩相似,微量元素投点也多落入岛弧玄武岩区。稀土含量特征及球粒陨石标准化模式与岛弧拉斑玄武岩的特征相似,W(∑REE)值高,且富轻稀土,稀土配分模式为右倾型。岩石组合、岩石化学及地球化学特 征指示其为早古生代不成熟的岛弧环境。大规模的火山活动形成了太阳寺一带原始地壳和初始矿源层,后经断裂改造,含矿热液活化转移,使成矿物质进一步富集成矿。     

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.     

Définition d'une limite multicritère ; stratigraphie du passage Campanien–Maastrichtien du site géologique de Tercis (Landes,SW France)Definition of a multi-criteria boundary; stratigraphy of the Campanian–Maastrichtian interval of the geological site at Tercis (Landes,SW France)

Lithostratigraphy, physicochemical stratigraphy, biostratigraphy, and geochronology of the 77–70 Ma old series bracketing the Campanian–Maastrichtian boundary have been investigated by 70 experts. For the first time, direct relationships between macro- and microfossils have been established, as well as direct and indirect relationships between chemo-physical and biostratigraphical tools. A combination of criteria for selecting the boundary level, duration estimates, uncertainties on durations and on the location of biohorizons have been considered; new chronostratigraphic units are proposed. The geological site at Tercis is accepted by the Commission on Stratigraphy as the international reference for the stratigraphy of the studied interval. To cite this article: G.S. Odin, C. R. Geoscience 334 (2002) 409–414.     

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.     

Late Wuchiapingian (Late Dzhulfian,early Late Permian) limestone olistolites within the Tertiary flysch of Glypia Unit (Mount Parnon,central–eastern Peloponnesus,Greece)

Some olistolites reworked in a Tertiary flysch of Mount Parnon (Peloponnesus, Greece) exhibit a Late Permian assemblage, dominated by Paradunbarula (Shindella) shindensis, Hemigordiopsis cf. luquensis and Colaniella aff. minima. This association corresponds to the Late Wuchiapingian (=Late Dzhulfian), a substage whose algae and foraminifera are generally little known. Contemporaneous limestones crop out in the middle part of the Episkopi Formation in Hydra, but they are rather commonly reworked in Mesozoic and Cainozoic sequences. The palaeobiogeographical affinities shared by the foraminiferal markers of Greece, southeastern Pamir, and southern China, are very strong (up to the specific level), and are congruent with the Pangea B reconstructions. To cite this article: E. Skourtsos et al., C. R. Geoscience 334 (2002) 925–931.     

PALEONTOLOGY

正20141596 Liu Yunhuan(School of Earth Sciences and Resources,Chang’an University,Xi’an 710054,China);Shao Tiequan Early Cambrian Quadrapyrgites Fossils of Xixiang Boita in Southern Shaanxi Province(Journal of Earth Sciences and Environment,ISSN1672-6561,CN61-1423/P,35(3),2013,p.39-43,3 illus.,20 refs.)     

GEOCHEMICAL EXPLORATION

正20141719 Chen Zhijun(State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences,Wuhan 430074,China);Chen Jianguo Automated Batch Mapping Solution for Serial Maps:A Case Study of Exploration Geochemistry Maps(Journal of Geology,ISSN1674-3636,CN32-1796/P,37(3),2013,p.456-464,2 illus.,2 tables,10 refs.)     

MICROPALAEONTOLOGY

正20140962 Chen Fenning(Xi’an Institute of Geology and Mineral Resources,Xi’an710054,China);Chen Ruiming Late Miocene-Early Pleistocene Ostracoda Fauna of Gyirong Basin,Southern Tibet(Acta Geologica Sinica,ISSN0001-5717,CN11-1951/P,87(6),2013,p.872-886,6illus.,56refs.)     

PETROLOGY

正1.IGNEOUS PETROLOGY20142008Cai Jinhui(Wuhan Center,China Geological Survey,Wuhan 430205,China);Liu Wei Zircon U-Pb Geochronology and Mineralization Significance of Granodiorites from Fuzichong Pb-Zn Deposit,Guangxi,South China(Geology and Mineral Resources of South China,ISSN1007-3701,CN42-1417/P,29(4),2013,p.271-281,7illus.,     

ENVIRONMENTAL GEOLOGY

正20141205Cheng Weiming(State Key Laboratory of Resources and Environmental Information System,Institute of Geographic Sciences and Natural Resources Research,CAS,Beijing 100101,China);Xia Yao Regional Hazard Assessment of Disaster Environment for Debris Flows:Taking Jundu Mountain,Beijing as an     

PROSPECTING EXPLORATION

正20141266Fan Chaoyan(Guangdong Provincial Key Laboratory of Mineral Resources and Geological Processes,Guangzhou 510275,China);Wang Zhenghai On Error Analysis and Correction Method of Measured Strata Section with Wire Projection Method(Journal of