Physics of Seismic Sources Ⅰ. Presentation of Seismic Sources     

Chen Yuntai  Wu ZhongliangInstitute of Geophysics  CSB  Beijing  China 《中国地震研究》1999,(2)

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Relationship between Mesozoic Magmatism and Subduction in the Da Hinggan-Yanshan Area   总被引：1，自引：0，他引：1  

SHAO Ji''anPeking University  Beijing LIU Futian  CHEN Hui  HAN QingjunInstitute of Geology  Geophysics  Chinese Academy of Sciences  Beijing 《《地质学报》英文版》2001,75(1)

High-resolution tomographic images of the belt crossing the Japan Trench-Changbai Mountains-Dong Ujimqin Qi are represented in this paper, revealing the shape of a subducted slab in the western Pacific region and characteristics of the lithospheric structures under the Changbai Mountains and the Da Hinggan Mountains. Studies of the spatial distribution, subduction time and the time-lag between the subduction and magmatism, combined with petrology and isotope geochemistry of the Late Mesozoic volcano-plutonic rocks from the Da Hinggan Mountains-Yanshan Mountains have further proved the independence of magmatic activities from the subduction of the Pacific plate. The Mesozoic tectono-thermal evolutionary history and structural characteristics of the lithosphere in the Da Hinggan Mountains and North China suggest that the formation and evolution of magma have probably a close relationship with the delamination and thinning of the continental lithosphere and the underplating resulting from the consequent up  相似文献   

Numerical Modelling of Ore-forming Dynamics of Fractal Dispersive Fluid Systems   总被引：9，自引：0，他引：9  

DENG Jun  FANG Yun  YANG Liqiang  YANG Junchen  SUN Zhongshi  WANG Jianping  DING Shijiang  WANG QingfeiChina University of Geosciences  Beijing China University of Geosciences  Wuhan Institute of Geology  Geophysics  Chinese Academy of Sciences  Beijing Jilin University  Changchun 《《地质学报》英文版》2001,75(2):220-232

Based on an analysis of the fractal structures and mass transport mechanism of typical shear-fluid-ore formation system, the fractal dispersion theory of the fluid system was used in the dynamic study of the ore formation system. The model of point-source diffusive illuviation of the shear-fluid-ore formation system was constructed, and the numerical simulation of dynamics of the ore formation system was finished. The result shows that: (1) The metallogenic system have nested fractal structure. Different fractal dimension values in different systems show unbalance and inhomogeneity of ore-forming processes in the geohistory. It is an important parameter to symbolize the process of remobilization and accumulation of ore-forming materials. Also it can indicate the dynamics of the metallogenic system quantitatively to some extent. (2) In essence, the fractal dispersive ore-forming dynamics is a combination of multi-processes dominated by fluid dynamics and supplemented by molecule dispersion in fluids and  相似文献   

Indosinian Foreland Fold-and-Thrust Belt Bordering Yunnan and Guangxi, China   总被引：2，自引：0，他引：2  

WU Genyao Institute of Geology  Geophysics  Chinese Academy of Sciences  Beijing 《《地质学报》英文版》2001,75(4):391-397

Recent discoveries of ophiolites indicate that there must be a Palaeotethyan geosuture zone bordering China and Vietnam, which separates the Vietbac block from the South China subcontinent. The Indosinian foreland fold-and-thrust belt bordering Yunnan and Guangxi provided further evidence for the palaeotethysides. The oceanic crust was subducted southwestwards while the magmatic arc migrated northeastwards, and the continent-arc collision occurred in the Late Triassic with the thrusting being extended towards the north or northeast. The features of thrust-nappe structure are discussed, which proved the continental margin of the Palaeotethyan ocean there to be a complicated one. A face-to-face collision occurred first along the NW-striking segment and then along the ENE-striking segment accompanied by transpression or oblique thrusting occurring along the NW-striking one.  相似文献   

Investigation of Fine Velocity Structure of the Basement Layer of the Shallow Crust in Western Yunnan Region     

Hu Hongxiang  Gao ShiyuInstitute of Geophysics  SSB  Beijing China 《中国地震研究》1995,(3)

In this paper the authors have discussed the results of investigation of fine velocity structure in the basement layer of the Simao-Zhongdian DSS profile in western Yunnan region.The depth of upper Pz interface of the basement layer is about 0-3.5 km,and the depth of the lower P1 interface is 11.0-17.0 km.The velocity of the basement layer on the southern side of the Jinhe-Erhai deep fault is 5.70-6.30 km/s,and has increased to 6.30-6.50 km/s on the northern side.Their transitional zone is situated near Jianchuan County.Along the profile some localities,where the faults cut across the lateral variation of Pz interface velocity,are quite obvious in addition to the variation in depth.The velocity isopleths are relatively sparse in the southern region of JYQ S.P.(shot - point),near the DC S.P.,and in the south ZT S.P.The magma has apparently risen up along the deep faults to the upper crust in these localities,forming a large intrusive rock zone in the basement layer.In Jinggu region the basaltic magma has  相似文献   

Deep Structures in China and Its Adjacent Areas: Plate Tectonics and Its Metallogenic Significance     

Chen Shengzao Institute of Geophysics  State Seismological Bureau  Beijing 《《地质学报》英文版》1995,69(3):223-239

This paper proposes a new tectonic pattern of the deep-seated structures in China and its adjacent areas (including the T - A - B system of the Ryukyu Islands). This is based on studies of the gravity field and gravity inversion coupled with the summation of the most recent achievements in geophysical studies. From a plate-tectonic point of view, the metallogenic characteristics and their indications at depth, as well as relevant geophysical-geological characteristics of four tectonic environments of the Chinese continent are analysed, and a classification of composite metallogenic provinces and belts and prediction of metallogenic prospects are made. The author extends the Kunlun-Qilian-Qinling tectonic belt to the T-A-B system of the Ryukyu Islands through the NW deep boundary of the Hangzhou Bay, and also proposes the following basic views' the migration and superposition of tectonic environments led to the formation of a composite metallogenic system; the change in the tectonic environment resulted  相似文献   

定点地形变仪的标定问题     

朱虎 《地震地磁观测与研究》1993,14(1):33-40

地形变仪器常用的标定方法可分两类:一类是间接标定法,它通过测定仪器的某几个参数而计算出仪器的格值,由于换算环节多,容易引进系统误差;另一类是直接标定法,它通过给出的一个已知物理量与仪器的输出信号对比来标定仪器的格值,此种方法精确度高,重复性强。大多数地形变仪可以用直接法标定,本文还介绍了用直接法对水平摆倾斜仪和浮子水管倾斜仪的标定。  相似文献   

中美青藏高原数字宽频带地震观测     

郑重 《地震地磁观测与研究》1993,14(1):41-44

1991年7月至1992年7月,中美合作在青藏高原进行了天然地震观测。布设了由11个台站组成的台阵,其中7个台站由北至南分布在青藏公路格尔木至拉萨段沿线,2个分别在其两侧,另外2个在青藏高原东部。此台阵使用REF TEK 72A-02记录器和宽频带STS-2地震计,进行事件触发及连续记录。此次观测为在青藏高原内采集地震数据提供了极好的机会。  相似文献   

N-DP新型数据回放仪的研制     

张焕生  马云生 《地震地磁观测与研究》1993,(3)

主要介绍N-DP新型数据回放仪的研制思路、结构、特点及应用情况。  相似文献   

中国地震报告数据处理系统   总被引：1，自引：0，他引：1  

陈培善  李强 《地震地磁观测与研究》1993,14(3):19-24

地震观测报告是一份具有广泛使用价值的地震基础资料。中国地震报告数据处理系统是提高中国地震报告质量的关键一环。其主要水平反映在:数据采集和处理自动化;采用最先进的数值计算方法;采用最先进的激光照排技术;用磁介质进行数据传递。  相似文献