Geochemical Characteristics of Sinian Manganese Deposits in China   总被引：1，自引：0，他引：1  

ZHU Kaijun  YAO GuolongTianjin Geological Academy  State Bureau of Metallurgical Industry  No. Youyi R  Tianjin 《《地质学报》英文版》2000,74(3):534-539

Sinian is one of the main periods of the formation of manganese deposits in China. Sinian manganesedeposits are mainly hosted in carbon-rich black shale and siliceous shale formed during the Sinian interglacial period. The composition of manganese ore is simple. The main ore mineral is manganiferous carbonates. The grade of manganese ore is about 16-25%, with Mn/Fe>5 and P/Mn=0.006-0.14. Based on the tectonic setting and geological and geochemical characteristics of manganese deposits, this paper discusses the process of migration and concentration of manganese and ore-forming conditions of Sinian manganese deposits in China.  相似文献   

Geochronology and Significance of Granites Associated with Gold Deposits in the Jidong Area, China   总被引：1，自引：0，他引：1  

Neal MCNAUGHTON  David GROVES 《《地质学报》英文版》2000,74(2):306-310

The Jidong area is located on the north margin of the North China craton. It is a nucleus composed of the oldest rocks in China. Precambrian metamorphic rocks with various Phanerozoic granitoids invaded are widespread. Gold deposits here have close spatial relations to granitoids. Some deposits occur within them and others in the outer zone of the contact belt of the intrusion, extending thousands of metres. There have been controversial views in regard to the relations of the deposits to the intrusions although traditional techniques have been used to date the intrusions. In order to solve such a problem, the SHRIMP technique was adopted to date the U-Pb ages of zircon collected from the Yuerya intrusion which hosts the large-sized Yuerya Au deposit and Qingshankou intrusion 2 km away from the Jinchangyu (larger-sized) Au deposit. Analysis shows that the ages of 175±1 Ma and 174±3 Ma for Yuerya intrusion and the age of 199±2 Ma for Qingshankou granite indicate the Early Yanshanian stage of the Meso-  相似文献   

利用卫星观测海面信息反演三维温度场   总被引：3，自引：0，他引：3  

王喜冬  韩桂军  李威  齐义泉 《热带海洋学报》2011,(6)

基于历史观测的温盐剖面资料,采用回归分析方法统计出海面温度异常、海面动力高度异常与温度剖面异常之间的相关关系;然后利用高分辨率的卫星遥感海表面温度(SST)和卫星观测海面高度(SSH)信息重构了三维海洋温度场。在台湾岛周边海域建立了时间分辨率为天、空间分辨率为0.25°×0.25°的三维温度分析场。通过与实测资料的比较分析,文章所构建的分析场能够较好地描述海洋三维温度场的结构特征,能够较为真实地反映海洋的中尺度变化过程。该分析场可以作为海洋数值模式的初始场,也可以作为伪观测同化到海洋数值再分析和预报系统中,进而改善三维温、盐、流的数值再分析和预报。  相似文献   

GPS测量揭示的福建沿海地区的现今地形变   总被引：12，自引：6，他引：6  

郭逢英  史粦华  丁学仁  林继华  刘序俨  黄声明  黄立人  马青 《大地测量与地球动力学》2003,23(3):87-92

根据福建GPS监测网3期(1997，1999，2001)观测资料的计算结果，分析了福建沿海地区的现今地形变特征。(1)福建地区有两个剪应变相对集中区，北部是湾口、闽清一带；南部是泉州、厦门一带。这两个区的剪应变随时间变化有加强的趋势。(2)南部剪应变集中区基本处于压应变环境，并且主要断裂两侧存在相对较高的剪应变集中区，值得关注。  相似文献   

基于断层相互作用的地震活动有限元模型   总被引：5，自引：1，他引：4  

陈化然  李轶群  汪翠芝  柴金翼  董晓阳 《大地测量与地球动力学》2002,22(2):86-90

基于断层相互作用，初步建立了西南地区有限元动力学模型，讨论了由于地震发生产生的应力变化对西南地区整个系统的应力调整情况。初步结果表明，许多强震均发生在应力增强区。因此，本模型对判断未来强震危险区有一定的意义。  相似文献   

华北地区地壳水平运动演化特征研究   总被引：13，自引：6，他引：7  

张跃刚  胡新康 《大地测量与地球动力学》2004,24(1):56-62

将华北地区划分为阴山-燕山、鄂尔多斯、山西、太行、冀鲁、胶辽6个块体，应用1995、1996、2001年GPS观测资料研究了这些块体的水平运动演化特征。结果显示出华北地区各块体的相对运动既有继承性也有差异性。华北各块体的总体水平运动趋势是向东漂移，但是个别块体，如鄂尔多斯块体，在1995～1996年期间出现了相对的西向运动。1995～1996年期间华北各块体的运动速率比1996～2001年期间的运动速率要大，特别是阴山-燕山块体。1995～1996年期间鄂尔多斯块体和相邻的山西块体表现为张性分离，阴山-燕山块体之间表现为左旋走滑，这一现象可能与1996～1999年期间发生在华北西北部的3个地震的孕震过程有关。进一步分析表明，加密的连续GPS观测可用于地震预报。  相似文献   

应用GPS观测资料反演潜在震源参数     

陈绍绪  李延兴  张跃刚 《大地测量与地球动力学》2004,24(1):72-76

根据点源孕震力学模型 ,应用福建 台湾地区GPS位移速度资料反演 1999年台湾南投Mw7.6大震前的孕震参数。反演所得的震中与实际发生的地震震中相差 6 7km ,主压应力场方向为 319.9°,倾角 - 2 8.6° ,即仰角2 8.6° ,与用震源机制解得到的P轴方向和倾角分别相差 17°和 8.6° ,与菲律宾板块向亚洲板块挤压的方向是一致的。用土耳其地区GPS位移速率资料反演 1999年土耳其Mw7.6地震前的孕震参数 ,反演得到的震中与实际震中相差 70km ,主应力方位角和倾角分别为 16 2 .5°、11.5°,与震源机制解结果分别差 2 4 .5°和 1.5°。  相似文献   

Impending HRT wave precursors to the Wenchuan M_s8.0 earthquake and methods of earthquake impending prediction by using HRT wave     

QIAN FuYe  ZHAO BiRu  QIAN Wei  ZHAO Jian  HE ShiGen  ZHANG HongKui  LI ShiYu  LI ShaoKun  YAN GuLiang  WANG ChengMin  SUN ZhenKai  ZHANG DongNing  LU Jun  ZHANG Ping  YANG GuoJun  SUN JiaLin  GUO ChunSheng  TANG YuXiong  XU JianMing  XIA KunTao  JU Hang  YIN BangHong  LI Ming  YANG DongSheng  QI WeiLuo  HE TaiMing  GUAN HuaPing & ZHAO YuLin Institute of Geophysics  China Earthquake Administration  Beijing  China  Tianjin Hi-tech Development Co. Ltd  Tianjin ... 《中国科学D辑(英文版)》2009,(10)

We deployed four geo-electric monitoring stations in Sichuan and Yunnan provinces from 2004, using the new generation of equipment (PS-100) and technologies to capture the HRT wave earthquake precursor. Before the Wenchuan Ms8.0 earthquake, we recorded the HRT wave precursor at the only operating station in Hongge (HG, Δ=465 km) and found that significant impending signal had been recorded at the station in the early morning ( 0―5 am) of 12th of May, 2008. The precursor for this earthquake is consistent wit...  相似文献   

秦岭造山带中两条新元古代岩浆岩带   总被引：42，自引：6，他引：36  

陆松年  陈志宏  李怀坤  郝国杰  相振群 《地质学报》2005,79(2):165-173

秦岭造山带中的新元古代岩浆岩带分为南、北两带,北带主要发育于秦岭岩群分布区,由新元古代早期花岗质岩石组成,由于受到强烈变质、变形,构成了NW向花岗片麻岩体群。岩石总体化学特征反映一种挤压性的动力学背景,其形成时代集中在95 5～84 4 Ma。南带分布于陡岭岩群分布区、南秦岭及“勉略构造带”以南的汉南一带,由双峰式火山岩、基性辉长岩侵入体及板内花岗质侵入岩组成。与北带花岗质岩石所受到的强烈变质、变形形成鲜明对比,除邻近构造带的岩体外,它们变质、变形程度较弱,以弱片麻状至块状构造为主,形成时代介于810～710 Ma之间,反映大陆地壳处于减薄的伸展机制。这条岩浆岩带的发育,显示秦岭造山带南部曾存在一条新元古代中期裂谷带,它是劳伦、澳大利亚和塔里木—扬子等大陆初始裂解的产物,也是古太平洋形成的前兆。  相似文献   

An IBEM solution to the scattering of plane SH-waves by a lined tunnel in elastic wedge space     

Zhongxian Liu  Lei Liu 《地震学报(英文版)》2015,(1):71-86

The indirect boundary element method(IBEM)is developed to solve the scattering of plane SH-waves by a lined tunnel in elastic wedge space. According to the theory of single-layer potential, the scattered-wave field can be constructed by applying virtual uniform loads on the surface of lined tunnel and the nearby wedge surface. The densities of virtual loads can be solved by establishing equations through the continuity conditions on the interface and zero-traction conditions on free surfaces. The total wave field is obtained by the superposition of free field and scattered-wave field in elastic wedge space. Numerical results indicate that the IBEM can solve the diffraction of elastic wave in elastic wedge space accurately and efficiently. The wave motion feature strongly depends on the wedge angle, the angle of incidence, incident frequency,the location of lined tunnel, and material parameters. The waves interference and amplification effect around the tunnel in wedge space is more significant, causing the dynamic stress concentration factor on rigid tunnel and the displacement amplitude of flexible tunnel up to 50.0 and17.0, respectively, more than double that of the case of half-space. Hence, considerable attention should be paid to seismic resistant or anti-explosion design of the tunnel built on a slope or hillside.  相似文献