桐柏—大别山高压超高压变质带

桐柏—大别山高压超高压变质带自南向北可划分为３个带：绿帘－蓝片岩相变质带，高压榴辉岩相变质和超高压榴辉岩相变质带，超高压变质带形成于加里东期洋壳俯冲作用过程中，而前两个高压变质带则是印支期陆－陆俯冲－碰撞作用的产物。     

康古尔塔格韧性剪切带变质作用研究

康古尔韧性剪切带是一个复杂而强烈的构造变形带，其特征表现为４个变形期次。由于韧性剪切──区域动力作用，使变质程度明显高于剪切带两侧的区域埋深变质，变质特征表现在葡萄石－绿纤石相经韧性变形作用后，形成一套低绿片岩相变质地层，体现出前进变质作用的特点──矿物普遍细粒化，并发生动态重结晶，这套低绿片岩相变质地层，为金的富集成矿提供了可靠的矿源层。     

新疆西南天山蓝片岩的变质作用pTDt轨迹及构造演化

西南天山蓝片岩的变质作用ｐＴＤｔ轨迹显示进变质作用为快速升压过程，退变质作用为近等热降压过程。自俯冲杂岩进入俯冲带到形成蓝片岩后抬升出露于造山带，变质作用经历了浊沸石相（４１５Ｍａ？）→硬柱石－蓝闪片岩相（４０８Ｍａ？）→蓝闪绿片岩相（３４５Ｍａ）→０绿片岩相（３１４Ｍａ）连续渐变演化的过程。蓝片岩中现存主要蓝闪绿片岩相矿物组合并非峰期变质矿物组合。造山运动晚期的大规模韧性推覆作用促成蓝片岩快速抬     

桂东南云开岩群斜长角闪岩的变质作用PT轨迹及其动力学意义

桂东南中新元古界云开岩群是一套中浅变质岩系,并形成一系列绿片岩相-角闪岩相的递增变质带,通过对云开岩群角闪岩相变质带(十字石-蓝晶石带)中斜长角闪岩变质作用的PT轨迹的系统研究显示,其包括了由早期绿片岩相变质阶段(M1)→峰期角闪岩相变质阶段(M2)→近等温降压变质阶段(M3)→近等压降温变质阶段(M4)→晚期绿片岩相退变质阶段(M5)五个阶段的顺时针PT演化轨迹,其地质动力学过程属于典型的板块俯冲碰撞→抬升模式,表明云开地块北缘造山带的地质构造演化经历了俯冲碰撞及碰撞后的快速抬升过程。     

内蒙古头道桥地区蓝闪石片岩和相关变质岩石岩石学特征及其构造意义

内蒙古头道桥地区出露了一套经高压变质形成的岩石组合。本次研究通过岩相学和矿物化学分析,根据矿物组合的不同,识别出蓝片岩、绿片岩两种不同类型的岩石类型。其中,蓝片岩的矿物组合为角闪石（蓝闪石、蓝透闪石）+绿帘石+钠长石+绿泥石+石英+赤铁矿±多硅白云母±方解石±榍石;绿片岩的矿物组合为绿泥石+钠长石+石英±绿帘石±角闪石（阳起石、镁角闪石、蓝透闪石、冻蓝闪石等）±多硅白云母±赤铁矿。确定了蓝片岩的峰期变质级别为绿帘-蓝闪片岩相,峰期变质温度为400~600℃,压力为1.2~1.4 GPa。绿片岩的峰期变质级别为绿帘-角闪岩相。结合前人研究成果,认为蓝片岩和绿片岩的形成与额尔古纳地块和兴安地块的碰撞拼合有关。     

陕西宽坪群某些前进变质矿物的研究

在宽坪群区域变质作用研究中,通过对某些前进变质矿物(角闪石、斜长石、黑云母、白云母、石榴石)成分结构的分析,不仅为了解这类矿物形成时的物理化学条件提供了较可靠的信息,而且为变质相带划分和变质相系确定提供了重要依据。这类矿物分布广,一般贯通整个变质带。其形态、光性及成分、结构随变质温度和压力的变化,显示宽坪群自南向北前进变质带(低绿片岩相—高绿片岩相—低角闪岩相)的存在或区域热流的分布状况。白云石和角闪石的成分及结构反映其形成于中压环境。这与变质泥质岩中出现的蓝晶石、十字石、铁铝榴石组合反映的中压相系特征是一致的。     

哀牢山—红河构造带古新世以来多期活动的构造和年代学证据

哀牢山—红河构造带哀牢山段可划分为东部高级变质带和西部低级变质带。构造分析表明:该构造带由3个不同变形域组成,可能代表其经历的3期左行走滑。第1期走滑发生在整个高级变质带,为拉张性左行走滑,形成角闪岩相L型构造岩。第2期走滑形成高级变质带中的高应变带,变形体制接近简单剪切,形成绿片岩相L-S型糜棱岩。第3期主要发生在低级变质带,为挤压性走滑,形成左行逆冲构造格局,并形成低绿片岩相千糜岩。地质年代学数据证明,3期左行走滑的形成时代分别是:距今58~56Ma、27~22Ma和13~12Ma±。哀牢山—红河构造带第1期左行走滑可能对应于印度与欧亚大陆距今60Ma左右的初始碰撞;第2期变形与青藏高原最强的挤压隆升期一致;第3期事件可能代表距今16~13Ma开始的青藏高原物质进一步东挤。哀牢山—红河构造带的3期主要左行走滑均发生在新生代印度与欧亚大陆的汇聚过程中。     

牡丹江地区蓝片岩中脉状青铝闪石~（40）Ar—~（39）Ar年龄及其地质意义

对穆棱县的磨刀石、椅子圈地区的蓝片岩研究，确定其经受过三期叠加变质作用：第一期为蓝片岩相变质作用；第二期为蓝闪绿片岩相变质作用；第三期为受断裂构造控制的动力变质作用，形成脉状青铝闪石、钠长石等变质矿物。通过对脉状产出的青铝闪石￣（４０）Ａｒ—￣（３９）Ａｒ年龄测定，获得较好的年龄谱，坪年龄为１５４．７±０．７Ｍａ。此年龄表明了该期变质作用与敦—密断裂发生大规模左行走滑有关，由于大型走滑断裂造成局部构造超高压，诱发了原有的蓝片岩中流体活化，而形成青铝闪石、钠长石、绿帘石等矿物组成的脉体沿剪切面分布。     

苏北海州群细碧角斑岩系的成因

海州群的变质火山岩地层,以石英角斑岩为主,细碧岩次之,角斑岩类稀少,属于细碧岩—石英角斑岩组合类型,且以普遍含钾偏高为特点。根据该岩系的岩相、岩石化学、稀土元素含量情况分析,它是元古代晚期在张性条件作用下产生陆内裂谷一海州裂陷槽,并形成海底火山喷发活动的产物。其中细碧岩和石英角斑岩分别来源于上地幔碱性玄武岩和硅铝地壳偏碱性流纹岩浆,所以具有双峰模式的组合特点。海州群沉积之后,曾多次发生区域性中一高压绿片岩相变质作用,分布上可划分为兰闪石绿片岩相、低绿片岩相、高绿片宕相等三个变质带,显示了递增变质的规律性变化。     

青藏高原可可西里地区三叠系巴彦喀拉山群低级-极低级变质作用

针对青藏高原可可西里的三叠系巴彦喀拉山群低级-极低级变质岩,利用X射线粉晶衍射分析确定了其矿物的共生组合、伊利石的结晶度Kubler指数(K)和b0值,并根据伊利石结晶度K和b0值对其区域变质作用的温压条件、分带、变质相进行了详细研究,得出了工作区5个不同岩性组合带的变质作用特征:昆仑山脉带属中压浅变质-近变质带,具葡萄石-绿纤石相和绿片岩相;不冻泉-库赛湖带属中压浅变质带,具绿片岩相;楚玛尔河带属中压近变质带,具葡萄石-绿纤石相;直达日旧带属中压浅变质带,具绿片岩相;五道梁带属中压近变质带,具葡萄石-绿纤石相.     

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