华北克拉通北部1.70Ga非造山环斑花岗岩岩套

北京裂谷是古克古代晚期在华北拉通太古代基底上直接发育的初生夭折裂谷。Ｕ－Ｐｂ年龄表明，位于裂谷的断陷台阶至断陷中的四条平行的东西向带是同时的岩套。这包括北部大斜长岩－纹长二长岩杂岩体；赤城－古北口岩带的斜长岩，含橄石英正长岩及富钾与环斑花岗岩；沙厂环斑花岗岩杂岩体及南部谷－蓟县火山岩带。     

元古代北京裂谷槽中钾质碱性火山—深成作用

北京东部密云－平岩－带，受中元古代拉张性断裂控制，裂谷断陷区内的大红峪组钾质碱性玄武质与响岩质火山岩在时间及空间上与侵入相球斑花岗岩－辉绿岩共生。它们具有相似的板内碱性玄开岩和Ａ型花岗岩的同位素及地球化学特征。双峰式铁镁质及硅铝质岩浆是上地幔及下地壳更低程度部分熔融产物。     

东秦岭北部富碱侵入岩岩石化学与分布特征

在东秦岭北部，富碱侵入岩的侵位与空间分布受同一个区域构造带（华并陆块南缘）控制，构成一个区域性的富碱岩浆岩带。根据岩石学和岩石化学研究，岩石类型主要分为三大类：（1）碱性岩类，即含有似长石或碱性暗色矿物的正长岩类；（2）碱性花岗岩类，包括钠铁闪石花岗岩及孪生的钾长花岗岩类；（3）石英正长岩类，包括碱性长石为主的石英正长岩、英碱正长岩和花岗正长（斑）岩类。根据富碱岩浆岩带的岩石化学特征，自北而南可以划分为三个亚带：北部碱性岩亚带，以SiO2饱和而l2O3不饱和出现碱性暗色矿物为特征；中部碱性花岗岩亚带，以SiO2强饱和而Al2O3不饱和出现碱性暗色矿物和大量石英为特征；南部石英正长岩亚带，以SiO2和Al2O3都饱和但CaO强烈亏损，缺乏Ca质斜长石，出现碱性长石占长石总量的绝对优势（一般＞95％）为特征。三个亚带富碱岩浆在化学成分方面虽有差异，但共同具有富碱高钾钙征，ALK＝10－15，K2O含量范围5％－15％，K2O／Na2O＝1．26－8．30。     

华南绍兴-恩平富碱侵入岩带的厘定及其动力学意义初探

根据野外地质及室内岩相学、矿物成分和岩石化学的研究，从华南腹地厘定了一条重要的中生代NE向富碱侵入岩带－绍兴－恩平富碱侵入岩带。该岩带全长约1400km，宽100－150km，不仅发育有狭义的碱性岩（方沸黑云橄榄黄长岩、白榴黄长煌斑岩、霞石正长岩、霓辉石正长岩、黑榴石正长岩和含霓石石英正长岩）和碱性花岗岩（钠闪石花岗岩、霓辉石钠闪石花岗岩），还发育有大量的正长岩类－二长岩类－碱长花岗岩或晶洞钾长花岗岩。这些富碱侵入岩主要形成于晚中生代。绍兴－恩平燕山期富碱侵入岩带的厘定将对研究华南中生代的动力学的背景与演化具有重要的意义。     

安徽两条A型花岗岩带

安徽长江两岸平行对称分布有两条Ａ型花岗岩带。江北为大龙山－城山－黄梅尖岩带；江南为花园巩－茅坦－浮山岩带。它们均由正长岩、石英正长岩和碱长花岗岩组成，形成年龄约１２８Ｍａ．这些岩石富碱贫水，全碱含量高达９％～１２％，而Ｈ２Ｏ＋只有约０．５％，富含高场强元素，Ｇａ×１０４／Ａｌ比值也高，花岗岩高达２．７～３．８。其形成环境为古裂谷拉张环境。两个岩带的花岗岩是正长岩浆通过ＡＦＣ（同化混染－分离结晶联合作用）机制演化形成，而正长岩浆则是碱性玄武岩浆通过以分离结晶为主的ＡＦＣ机制形成．     

水泉沟杂岩体的地质学和岩石学研究

水泉沟岩体为岩浆成因，岩体的侵位深度２－３ｋｍ，侵位时代为印支期，划分为４种岩石组合１，水泉沟岩体是一个钾质－高钾质的钙碱性，弱碱性和碱性岩石共存的杂岩体。岩石化学成分变异图解证明岩浆存在两种演化趋势，一是酸性演化趋势；辉石闪长岩－角闪二长岩－石英碱长正长岩－碱长花岗岩；二是碱性演化趋势；正长岩－霓辉正长岩－碱长正长岩。     

宽甸环斑花岗岩的同化混染成因

环斑花岗岩是发育于前寒武纪的一种特殊岩石。本文从环斑花岗岩的地质学、岩石学及矿物学等方面讨论了宽甸元古宙环斑花岗岩的成因,认为环斑花岗岩是由分异出石英二长岩的富钾质残余岩浆在深部同化围岩(类似盖县组的矽线石榴黑云斜长片麻岩及黑云母变粒岩等岩石)形成的含大量围岩捕虏晶的晶粥状岩浆,经侵位结晶而成。环斑长石的斜长石外壳是来自围岩的捕虏晶,它通过流动、吸附作用附着于钾长石巨晶的周围,构成环斑结构。     

北京及附近元古宙裂谷槽中球斑花岗岩套的地球化学

北京及其以东地区(河北省境内)受东西向断裂制约,侵入了一套元古宙(1.4—1.8 Ga)的球斑花岗岩套,并形成了3条侵入岩及火山岩带。斜长岩/辉长岩及碱性玄武岩与含橄石英正长岩、球斑花岗岩及粗面岩构成的双峰式岩石组合,和钾质A型花岗岩及非造山花岗岩的同位素、微量及稀土元素地球化学等资料,都说明本区存在一个初期裂谷。由上地幔及下地壳低比例熔融派生的混合岩浆,经分离结晶形成堆积斜长岩。缺水的花岗岩浆,分异演化成钾质次碱性花岗岩系列,分离结晶不彻底时,则形成韵律式喷溢行动。     

元古代北京裂谷槽中钾质碱性火山－深成作用

北京东部密云一平谷一带，受中元古代拉张性断裂控制，裂谷断陷区内的大红峪组钾质碱性玄武质与响岩质火山岩在时间及空间上与侵入相球斑花岗岩一辉绿岩共生。它们具有相似的板内碱性玄武岩和Ａ型花岗岩的同位素及地球化学特征。双峰式铁镁质及硅铝质岩浆是上地幔及下地壳更低程度部分熔融产物。     

A型花岗岩的岩石学亚类及其物质来源

评述和总结了国内外Ａ型花岗岩的岩石学特征,指出目前被划归为这类的岩石至少包括非造山和造山两种环境的７种类型（或组合）,即：①环状杂岩体中的碱性及准碱准铝质岩类;②斜长岩微纹二长岩紫苏花岗岩和钾质（环斑）岩花岗岩类;③层状杂岩体中的酸性岩类;④正长岩花岗岩类;⑤二长正长花岗岩类;⑥碱长碱性花岗岩类;⑦碱钙性花岗岩类。认为这些岩石的差异本质上反映出它们物质来源的多样性,亏损地幔、原始地幔、富集地幔、壳幔和地壳物质是这些岩石的潜在源岩。     

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