利用InSAR技术研究黄土地区滑坡分布

InSAR技术能够获取大面积、连续、高精度的地表垂直形变信息,可用来监测地震、火山、滑坡等自然灾害造成的地表形变。文章介绍了InSAR技术在监测陕北黄土地区滑坡中的应用,首先进行野外地质勘察和TM光学遥感影像解译,接着通过EnviSat SAR数据差分干涉处理,获取研究区干涉形变场,提取出滑坡位移量,最后详细分析黄草湾至董家寺沿线一带的滑坡变形范围,并划定出了4个有一定变形的重点监视区。     

湖北清江和尚洞风化岩壁放线菌分离及基于16S rRNA的种类分析

为探究湖北清江和尚洞岩壁放线菌物种组成及其与碳酸盐岩相互作用的关系,分别采集该洞穴无光区风化岩壁样品2份（W1和W2）和弱光区风化岩壁样品1份（W3）,采用经改良的5种已知放线菌分离培养基及1种自主设计的风化岩壁浸汁培养基两种策略优化设计分离培养基。采用稀释涂布法分离放线菌,并选择放线菌特异引物进行16S rRNA基因扩增和序列测定并构建系统发育树。结果表明,从3份风化岩壁样品中共纯化到放线菌72株,分属于放线菌纲（Actinobacteria）的4个属:链霉菌属（Streptomyces,69株）、红球菌属（Rhodococcus,1株）、冢村氏菌属（Tsukamurella,1株）和微杆菌属（Microbacterium,1株）,其中链霉菌属为优势菌属。无光区样品W1和W2分离到菌株较少,分别为9株和10株,而弱光区样品W3分离到菌株较多,为53株。研究结果为进一步研究放线菌与洞穴碳酸盐矿物相互作用的潜在关系奠定了基础。      

青藏铁路设计与建设——第六届国际冻土工程会议回顾

The 6^th International Symposium on Permafrost Engineering was successfully held in China in September 2004. About 150 scientists and engineers from 7 countries attended the symposium in Lanzhou on 5～7 September, and about 35 people from 6 countries participated in the field trip along the QinghaiTibet Highway/Railway on 8～13 September and the seminar in Lhasa on 14 September 2004. During the Symposium, the latest progress on permafrost engineering and the surveys, design and construction of the Qinghai-Tibet Railway were exchanged and inspected. Fifty-eight technical papers in English from the Symposium were published in the first volume of the Proceedings of the Symposium, as a supplement of the Journal of Glaciology and Geocryology, before the symposium. About 6 papers from the symposium are published in the second volume in the volume 27(1) of the Journal of the Glaciology and Geocryology, after the symposium. The Qinghai-Tibet Railway (QTR) under construction will traverse 632 km of permafrost, and the engineers are facing unprecedented engineering and environmental challenges. With the QTR under construction and to be completed in 2007, permafrost engineering has become the research focus of permafrost scientists and engineers in China. Many encouraging and promising achievements in permafrost engineering have been obtained during the past three years. However, there are still numerous engineering and environmental problems needing to be solved or resolved. In the discussions, some experts pointed out that methods, such as removal of snow cover on the embankments and toe areas, light-color embankments and side slope surfaces, awnings for shading the solar radiation, hairpin or tilted thermosyphons, could be applied to actively cool the roadbed of the QTR. Some new ideas on utilization of the natural cold reserves were proposed to protect the QTR permafrost roadbed from thawing. Many questions and answers on the survey, design, construction, operations, maintenance and environmental protection were exchanged in situ and in the Lhasa seminar with participation by some major railway designers, regulators and administrators.     

云南羊拉铜矿床成矿流体特征及成矿过程

云南羊拉铜矿床位于金沙江构造带中部,是中-晚三叠世金沙江洋盆向西俯冲闭合碰撞造山过程中形成的一个大型铜矿床。矿体多呈层状、似层状顺层产出,但明显受层间破碎带和滑脱带控制。从流体包裹体研究入手,讨论了该矿床成矿流体的特征、演化以及流体不混溶(沸腾)作用与成矿的关系。流体包裹体研究表明,干夕卡岩阶段(Ⅰ)、湿夕卡岩磁铁矿阶段(Ⅱ)、石英硫化物阶段(Ⅲ)以及方解石硫化物阶段(Ⅳ)中发育多种类型的包裹体,主要为气液水两相包裹体和含子矿物多相包裹体,纯液相水包裹体次之,少见纯气相有机质包裹体。其中,含子矿物多相包裹体发育于Ⅰ阶段石榴石、Ⅱ阶段绿帘石,尤其是Ⅲ阶段石英中。Ⅰ、Ⅱ阶段成矿流体具有高温、高盐度特征,均一温度分别为413~593 ℃和336~498 ℃,盐度分别为19.1%~49.7% NaCleq和15.7%~53.3% NaCleq;Ⅲ阶段成矿流体均一温度为148~398 ℃,并具有低盐度(2.1%~9.6% NaCleq)与高盐度(35.5%~65.3% NaCleq)共存的特征;Ⅳ阶段成矿流体具有低温(132~179 ℃)、低盐度(3.4%~10.4% NaCleq)特征。根据流体包裹体的微观特征并结合矿区的宏观地质特征,认为流体不混溶(沸腾)是导致本矿区金属沉淀成矿的主要机制。     

Groundwater System Division and Description of Asia

Based on landform, climate, river system, geological structure and hydrogeological structure and from the perspective of systematology, the groundwater system of Asia can be divided into 36 secondary groundwater systems under 11 primary ones by the intercontinental scale. This forms part of the work of the groundwater series map of Asia, which is compiled according to groundwater system division and evaluation of the total amount and types of aquifer, reflecting the large-scale features of groundwater resources in Asia. Systematic profiling of groundwater in this way provides a scientific basis for groundwater exploitation planning and management in Asia, and avoiding disputes over groundwater resources and the environment among Asian countries.     

中国大陆壳体的区域元素丰度

中国大陆壳体由华夏壳体、西域壳体和藏南壳体构成。本文给出这３个壳体的质量模型和元素丰度,并从成矿元素,热源元素和镧系元素方面讨论它们的区域丰度特征。结论认为,它们的地球化学背景是各不相同的。     

地震作用下丰满重力坝的塑性损伤

基于混凝土塑性损伤本构模型,将可以表征材料和结构渐进破坏的损伤变量作为内变量,考虑了混凝土拉压异性的损伤变量,利用有限元软件ABAQUS,对丰满混凝土重力坝在经受地震作用下的结构损伤区域的发展变化进行安全性评价。在数值计算过程中,对于受地震荷载作用所引起的地面水平运动而导致大坝水位水平运动对坝体的影响,通过扩充后的广义Westergaard公式予以计算模拟。通过分析得到了丰满大坝在地震作用下的塑性损伤破坏情况,并评价了丰满大坝的安全性,亦说明利用损伤力学对大坝进行安全性评价是一个可行的方法。     

Tectonic Units Division of Crystalline Basement in the Tarim Basin, NW China

<正>By the geological investigation for crystalline basement outcrops in Northeast and northwest margins of Tarim Basin,we provide essential constrains interpreting the structure,petrology and age of the pre-Sinian basement.On the basis of interpretation for aeromagnetic anomalies,     

山西原平王家庄条带状磁铁石英岩矿床元素地球化学特征及其地质意义

山西原平王家庄铁矿床为五台山地区产出的条带状铁建造（BIF）的典型代表。含矿岩石为磁铁石英岩,围岩主要为斜长角闪岩、角闪变粒岩、石英片岩等。通过对变质岩的原岩恢复,得出其原岩主要为火山岩,具有从拉斑玄武岩向钙碱性火山岩演化的特点,局部有陆源碎屑的加入。微量元素中相对亏损Ta、Nb、Zr、Ti等高场强元素,相对富集K、Rb等大离子亲石元素,具有较低的w(Y)/w(Nb)比值,表明本区处于岛弧和活动大陆边缘带的构造环境。磁铁石英岩的稀土元素配分型式为向右缓倾斜的轻稀土富集型,具轻微铕正异常和轻微铈负异常,稀土元素特征表明BIF形成于典型的海洋环境,早太古代洋壳俯冲产出的高温气水热液对于BIF的沉积发挥了重要的作用。Eu轻微正异常说明本区火山活动较弱,海底高温热液对BIF的沉积贡献相对较少。BIF与其围岩在原始地幔标准化不相容元素蛛网图中的相关性说明二者有相同或相似的物质来源和成岩环境,二者同属一个沉积盆地,但却有不同的沉积过程和形成条件。     

西天山阿希型金成矿系列的成矿流体特征

西天山吐拉苏盆地中发育的低硫浅成低温热液型金矿、斑岩型金矿和层控浅成低温热液改造型金矿属于与晚古生代火山次火山岩系有关的金矿组合———阿希型金成矿系列。通过对各类型金矿含金石英脉矿物包裹体流体成分的分析 ,吐拉苏盆地中可以区分出两期不同的流体场 ,分别是成矿前的统一流体场和成矿期的局部流体场。前者是伴随着早石炭世大哈拉军山组火山爆发而形成的产物 ;后者是在成矿前统一流体场的基础上 ,受局部热动力活动影响而形成的局部成矿流体场 ,又可分出 3种不同的类型。成矿前统一流体场与成矿期 3种局部流体场流体均属于K+SO2 -4型 ;总体特征上具有相似性 ,均为火山、岩浆热液水和大气水的混合水 ;流体成分有随时间而呈有规律变化的现象 ;阳离子K+和阴离子SO2 -4随时间逐步减少 ,表明火山、岩浆活动随时间对流体的影响逐渐减弱 ;水的含量逐步增高 ,则表明流体随时间大气水参与程度的提高 ,同时流体的浓度也逐步降低