库鲁克塔格赛马山一带中元古界构造变形研究

通过构造解析的研究，确定赛马山地区中元古代所发生的阿尔金运动共有三幕变形，第一幕发生在长城纪早期，为EW向伸展机制下中部构造相的大规模顺层滑脱韧性变形，形成了赛马西山顺层滑脱韧性变形带，具超塑性流动变形特征和多层结构样式，第二幕发生在长城纪末，为主期变形，在NS向挤压机制下，在浅部构造相形成了EW向紧闭褶皱（局部倒转褶皱），并卷入早期的顺层滑脱韧性变形带，褶皱后期，由于应力的集聚，在浅表层次下，沿兴地塔格群内岩层软弱面发生剪切而形成了滑脱面，产生由南向北的逆冲，形成了具叠瓦扇结构的永红山飞来峰构，第三幕，蓟县纪末由于SN向强烈挤压后出现“松驰”引张而产生EW向挤压应力，形成NS向开阔褶皱，叠加于主期褶皱之上，形成了赛马西山－永红山穹盆构造。     

楚雄盆地中—新生界构造变形特征

根据近年笔乾研究，楚雄盆地中生代以后经历三期变形作用：早期（燕山期）主要发育于密者挤压逆冲带，显示横向置换特征，中期（喜马拉雅早期）是主变形期，西带显示由SW向NE逆冲，以叠瓦状闻和冲构造系统为其特征，晚期（喜马拉雅中晚期）发育于陡坡和深切割区，表现为重力滑动构造，这些构造期次的确定为研究该盆的发展，演化提供理论依据，亦为寻找油气资源提供靶区。     

西昆仑山南缘上三叠统变质岩系及构造变形特征

西昆仑山南侧沿北西向分布的变质复理石海相碎屑岩系，其时代主要属晚三叠世，是巴颜喀喇山群的西延部分，它的东段和西段岩石变质程度、构造样式和变形机制的不同，是同一构造带中不同的构造层次构造的反映，东段属下部构造层次，西段属深部构造层次和深熔花岗岩，它们形成于晚三叠世昆仑地块南缘的陆缘盆地，印支期褶皱变质，燕山期和喜山期的挤压，抬升和剥蚀，使东西两段出露了于不同深度构造层次形成的构造。     

沁水盆地南缘中-新生代构造变形与构造应力场

沁水盆地南缘自中生代以来,主要经历了印支期、燕山期、喜马拉雅期三期构造活动的影响。通过对地表露头的断 层面擦痕、纵弯褶皱及共轭节理系的研究,获得了古构造应力场信息。在研究区东部 NNE 向的太行山断裂带内,逆冲挤压 构造非常明显,与其相伴发育的不对称背斜构造表明其主压应力方向为 110°;中部的 EW 向正断层、地堑系可能是印支期 近 SN 向挤压作用下形成的逆冲构造经历了新生代构造反转作用而产生的,新生代伸展作用非常显著,伸展方向为 26°, 249°,347°;西部边界由近 SN 向断裂组成,存在新生代近 EW 及 NEE-SSW 向伸展运动的擦痕证据,伸展方向为 94°,72°。 区内发育 NNW-SSE,NW-SE,NE-SW,NEE-SWW,近 SN 等几个方向的共轭节理系,表明存在过燕山期 NW-SE 向的水平 挤压构造应力场和喜山期 NE-SW 向水平挤压构造应力场,近 EW 向水平挤压应力场可能是在这两期主要构造应力场转换过 程中形成的。     

兰坪盆地某些逆冲推覆构造研究

本文厘定了兰坪盆地某些逆冲推覆构造的存在并作了深入的探讨。提出该区推覆构造属由西侧的自南西西向北东东推覆和东侧的自北东东向南西西推覆的两组逆冲断层组成的对冲结构类型。通过宏观和微观资料的综合研究，构造应力场属晚特提斯构造活动的一部分，即印度板块与欧亚板块会聚时，于滇西派生出北东东一南西西向的挤压应力场，形成陆壳内部边缘以脆性变形为主的薄皮构造。推覆构造主要形成于喜马拉雅运动早期，对其深入研究，于滇西喜马拉雅期构造特征的认识具有重要的意义。     

甘肃北山小西弓—红旗山地区中新生代变形构造及其形成机制

本文通过ＴＭ影像解释和野外验证，论证了研究区内近ＥＷ向构造带除在前中生代遭受了强烈的近ＳＮ向挤压变形外，还在中新生代叠加了脆－韧性和韧性两期近水平右扭剪切变形以及一期脆性变形，形成了现今的挤压带、剪切带和脆性断裂叠加的复杂构造格局。文中还对各期变形的最大主压应力方位、变形时代以及构造形成机制和演化进行了探讨。     

湘中龙山地区变形序列及金锑矿控矿构造

龙山金锑矿区位于湘中盆地龙山穹窿内。关于湘中地区上古生界中不同方向褶皱和龙山穹窿的形成时代均存在多种观点,对龙山金锑矿区内含矿断裂的运动学特征和时代背景等缺乏观测和认识。鉴此,笔者等根据大量地表和井下露头构造观测和解析,结合区域构造特征、矿床地质特征和已有区域构造事件研究成果,厘定了龙山金锑矿及邻区的构造变形序列以及上古生界中褶皱和龙山穹窿的形成时代,探讨了构造控矿规律及动力学机制。主要成果认识如下：(1)研究区自早至晚经历了奥陶纪末—志留纪NW向挤压、中三叠世晚期NW向挤压、晚三叠世SN向—NNE向挤压、中侏罗世晚期NWW向挤压、白垩纪区域NW—SE向伸展和古近纪中晚期NE向挤压6期主要变形事件;(2)上古生界中NE向褶皱形成于中三叠世晚期,EW向褶皱形成于晚三叠世,NNE向褶皱形成于中侏罗世晚期;龙山穹窿形成于中三叠世晚期NE向复背斜与晚三叠世EW向复背斜的叠加;(3)两期复背斜核部因应力集中而更易形成导矿、容矿断裂,加之穹窿构造常伴随隐伏花岗岩体,导致龙山金锑矿定位于龙山穹窿的中部。龙山金锑矿的导矿构造为两期复背斜相关的NE向和EW向隐伏逆冲断裂;容矿构造为中三叠晚期形成的NWW...     

变质构造岩类型及其特征

变质构造岩是由变质变形作用形成的一种特殊类型岩石,形成于地壳不同构造层次上的韧性变形带中,具有明确的构造成因的含义。依据变形机制、组构、同构造新生矿物组合,以及形成环境,将韧性剪切带中变质构造岩分为构造片麻岩系列、构造片岩系列和糜棱岩系列。构造片麻岩系列形成于地壳深部构造层次上,以颗粒流动和扩散蠕变变形机制为主,宏观上表现为条纹和条带状构造,微观上为三边平衡结构。构造片岩系列形成于地壳中浅部构造层次上,以位错蠕变和新矿物化作用为主,由同构造新生片状矿物和基质组成。糜棱岩系列主要以位错蠕变变形机制为主,动力重结晶现象普遍,由残斑和基质两个部分组成,粒度变细,S-L组构发育,形成于地壳中-中浅部层次。     

新疆南天山科克苏河地区构造变形特征

本文通过对南天山科克苏河地区构造变形特征的研究，总结出会聚板块边界造山运动过程中构造变形的演化规律为：造山运动早期，板块俯冲作用促成俯冲杂岩发生蓝片岩相变质作用的同时，发育深层次韧性挤压变形构造；俯冲作用停止后，蓝片岩抬升、拆返过程中遭受韧性挤压变形叠加；造山运动晚期，则发育大规模韧性逆冲构造和韧性平滑走滑构造；造山运动末期，发育浅层次韧脆性开阔褶皱、区域性同斜倒转褶皱及逆冲断层。     

中国中,新生代板内变形与构造应力场

在综合区域地质、古地磁、构造变形与古构造应力分析的基础上,作者对中国中、新生代进行了构造期的划分,将其分为6个构造期:(1)印支期(250-208Ma),(2)燕山期(208-135Ma),(3)四川期(135-52Ma),(4)华北期(52-23.3Ma),(5)喜马拉雅期(23.3-0.73Ma),(6)新构造期(0.73Ma以来)。      

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