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Science China Earth Sciences 2005年第8期48卷 1089-1105页

作者： FAN Qicheng1,2. ZHANG Hongfu1, SUI Jianli1, ZHAI Mingguo1, SUN Qian2.& LI Ni2.1. institute of Geology and geophysics, Chinese Academy of Sciences,{2. 10002., China 2. institute of Geology, China seismological bureau,{2. 10002., China 1. institute of Geology and geophysics Chinese Academy of Sciences 100029 Beijing China 2. institute of Geology China Seismological Bureau 100029 Beijing China

On the basis of mineral assemblage, mineralogy, petrology, and major, trace ele-mental and isotopic geochemistry of the underplated granulite- and eclogite-facies accumulate, peridotite and pyroxenite xenoliths entrained in Hannuoba Cenozoic basalts, this work con-strained the petrological constituents for the crust-mantle transitional zone, which is supported by the results of high-temperature and pressure velocity experiments on rocks and geophysics deep survey. Present lower part of lower crust is mainly composed of granulite-facies mafic accumu-lates (dominantly plagioclase websterite) and crust-mantle transitional zone dominantly com-posed of eclogite-facies pyroxenites with or without garnet and spinel lherzolites; Archaean ter-rain granulite is only nominally early lower crust. Magma underplating in the crust-mantle boundary led to the crustal vertical accretion and the formation of the crust-mantle transitional zone, which is a significant mechanism for the chemical adjustment of the crust-mantle boundary since the Phanerozoic.

关键词： magma underplating, xenolith petrology, geochemistry, cust-mantle boundary constituent, Hannuoba.

Si-and alkali-rich melt inclusions in minerals of mantle peridotites from eastern China:Implication for lithospheric evolution

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Science China Earth Sciences 2006年第1期49卷 43-49页

作者： FAN Qicheng1, SUI Jianli2. XU Ping2. LI Ni1, SUN Qian1 & WANG Tuanhua1 1. institute of Geology, China seismological{2., beijing 10002., China 2. institute of Geology and geophysics, Chinese Academy of Sciences, beijing 10002., China 1. institute of Geology China Seismological Bureau Beijing 100029 China 2. institute of Geology and geophysics Chinese Academy of Sciences Beijing 100029 China

Minerals of spinel- and garnet-facies mantle xenoliths entrained in Cenozoicbasalts from eastern China (North China, Northeastern China and Southeastern China coastal area)contains lots of melt inclusions. Studies on these melt inclusions show that the glass inclusionsare rich in SiO_2.(60%—68%) and alkalis (K_2.+Na_2. = 5%—11%, especially for K_2.) as well asvolatiles such as H_2. and CO_2.(2.—7%), which belong to dacites and andesites of the high-K calcicalkali series rocks with few shoshonites. High Al and Ca diopside in melt inclusion is the productof melt crystallization at high temperature and pressure, rather than the product ofdevitrification. Results show that these K-rich (in general K_2. > 3%) intermediate-acidic silicatemelt inclusions have characteristics of continent without a genetical link to host basalts and theirphenocrystic minerals. Thus, these trapped melt inclusions represent melts of Mesozoic lithosphericmantle-crust interaction and imply that the continental lithospheric mantle beneath eastern Chinahad undergone fragmentation and recreation processes during the Mesozoic and Cenozoic periods. Thisresult undoubtly provides important implication for the evolution of sub-continental lithospherebeneath eastern China. We propose that these Si- and alkalis-rich melts should be responsible forthe mantle chemical heterogeneity underneath eastern China.

关键词： Si- and alkali-rich melt inclusion, mantle peridotite, lithospheric evolution, eastern China.

Crustal structure of Gondwana-and Yangtze-typed blocks:An example by wide-angle seismic profile from Menglian to Malong in western Yunnan

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Science China Earth Sciences 2005年第11期48卷 1828-1836页

作者： ZHANG Zhongjie1, BAI Zhiming1, WANG Chunyong2. TENG Jiwen1, Lü Qingtian3, LI Jiliang1, SUN Shanxue1 & WANG Xinzheng1 1. institute of Geology and geophysics, Chinese Academy of Sciences,{2. 10002., China 2. institute of geophysics, Chinese seismological bureau,{2. 100081, China 3. institute of Deposition Resource, Chinese Academy of Geological Sciences,{2. 100037, China 1. institute of Geology and geophysics Chinese Academy of Sciences 100029 Beijing China 2. institute of geophysics Chinese Seismological Bureau 100081 Beijing China 3. institute of Deposition Resource Chinese Academy of Geological Sciences 100037 Beijing China

The wide-angle seismic profile between Menglian and Malong crosses the Baoshan block (Gondwana-typed), and Simao and southwestern Yangtze blocks (Yangtze-typed). By in-terpreting the wide-angle seismic data, we obtained the seismic crust/upper mantle structure of P-wave velocities together with the seismic reflections of these three blocks, Changning- Menglian and Mojiang suture zones among the mentioned three blocks. Our interpreting results demonstrate that the P-wave crustal velocity of Simao block is slower than that of Baoshan and southwestern Yangtze block and the crustal thickness gradually thickens from the Baoshan block, Simao to southwestern Yangtze block. Crustal reflection patterns of these three blocks have dis-tinct differences too. For the Gondwana-typed blocks, seismic reflections in the upper crust are well developed while in middle-lower crust they are very weak. The crustal reflections in the Yangtze block are very well developed. The crustal reflection patterns in Simao and southwest-ern Yangtze blocks are distinguishable. The average thickness of the crust in the studied area is about 40 km. And we make some discussions on the crustal thickening model of the three blocks in western Yunnan and tectonic setting of seismic developing and interaction of Gondwana and Yangtze blocks.

关键词： Gondwana blocks,Yangtze blocks,wide-angle profile,crustal structure,tectonic setting

The crustal structure under Sanjiang and its dynamic implications:Revealed by seismic reflection/refraction profile between Zhefang and Binchuan,Yunnan

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Science China Earth Sciences 2005年第9期48卷 1329-1336页

作者： ZHANG Zhongjie1, BAI Zhiming1, WANG Chunyong2. TENG Jiwen1, Lü Qingtian3, LI Jiliang1, LIU Yifeng1 & LIU Zhenkuan4 1. institute of Geology and geophysics, Chinese Academy of Sciences,{2. 10002., China 2. institute of geophysics, China seismological bureau, beijing 100085, China 3. institute of Deposition Resource, Chinese Academy of Geosciences,{2. 100037, China 4. School of Exploration and Information, China University of Geosciences,{2. 100083, China 1. institute of Geology and geophysics Chinese Academy of Sciences 100029 Beijing China 2. institute of geophysics China Seismological Bureau 100085 Beijing China 3. institute of Deposition Resource Chinese Academy of Geosciences 100037 Beijing China 4. School of Exploration and Information China University of Geosciences 100083 Beijing China

The fault belts in Sanjiang mainly include Jinshajiang-Honghe fault, Lancangjiang fault and Nujiang fault (called Sanjiang faults) in western Yunnan Province, China. By interpreting the wide-angle seismic reflection/refraction profile between Zhefang and Binchuan, which crosses Tengchong and Baoshan blocks in Dianxi (western Yunnan) tectonic zone, we recon- struct the crustal structure with seismic traveltime tomography for crustal P-wave velocity and the seismic scattering image for crustal seismic reflection structure. In this paper, we firstly present the crustal structure images of P-wave velocity and seismic reflection under the wide-angle seismic profile. These results demonstrate that, the crustal velocity structure and seismic reflec- tion structure along the profile can be divided into 3 segments, and there is an obvious difference of crustal structure among the eastern, the western and the middle segment. Generally, crustal P-wave velocities in the Baoshan segment are 0.1―0.2.km/s slower and seismic reflection am- plitudes from Moho discontinuity are stronger than the other 2.segments. In the studied area, crustal thickness is about 40 km, and shows the thickening tendency from west to east along the profile. Additionally, it can be seen that there is one strong-amplitude seismic reflection event as bright points at the depths of 8―10 km, along the segment of 80―115 km of the profile (south- ward of Tengchong); and seismic reflection wave-field from Moho discontinuity varies obviously along the lateral direction. Finally, we make some discussions on the crustal thickening pattern in the Sanjiang fault belt, structural environment of earthquake development and the contact rela- tionship between the Tengchong block, Banshan block and Luxi trough.

关键词： Sanjiang area wide-angle seismic profile crustal structure.

Dynamic mechanisms of the post-seismic deformation following large events:Case study of the 1999 Chi-Chi earthquake in Taiwan of China

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Science China Earth Sciences 2009年第11期52卷 1813-1824页

作者： ZHU ShouBiao1,2.& CAI YongEn2.1 institute of Crustal Dynamics, China Earthquake Administration, beijing 100085, China 2.Department of{2., Peking University, beijing 100871, China 1. institute of Crustal Dynamics China Earthquake Administration Beijing 100085 China 2. Department of geophysics Peking University Beijing 100871 China

The mechanism of postseismic deformation related to strong earthquakes is important in geodynamics, and presumably afterslip or viscoelastic relaxation is responsible for the postsesimic deformation. The 1999 Chi-Chi, Taiwan of China, earthquake occurred in the region where GPS observation station is most densely deployed in the world. The unprecedented GPS data provides a unique opportunity to study the physical processes of postseismic deformation. Here we assume that the interactions of viscoelastic relaxation, afterslip, fault zone collapse, poroelastic rebound, flow of underground fluids, and all these combined contribute to the surface displacements following the main shock. In order to know the essence of the postseismic deformation after the strong event, fault zone collapse, poroelastic rebound, flow of underground fluids, and so on, are represented equivalently by the variations of the focal medium properties. Therefore, the viscoelastic relaxation, afterslip, and the variations of the equivalent focal medium properties are inverted by applying the GPS temporal series measurement data with viscoelastic finite element method. Both the afterslip rate distribution along the fault and the afterslip evolution with time are obtained by means of inversion. Also, the preliminary result suggests that viscosities of the lower crust and the upper mantle in Taiwan region is 2.7×1018 and 4.2.102. Pa·s, respectively. Moreover, the inversion results indicate that the afterslip contributing to postseismic deformation of 44.6% in 450 days after the Chi-Chi earthquake, with 34.7% caused by the viscous relaxation and 2..7% by other factors such as fault zone collapse, poroelastic rebound, and the flow of liquids.

关键词： mechanism of postseismic deformation viscoelastic finite element method GPS temporal series data Chi-Chi earthquake

The age of the plant fossil assemblage in the Liuqu Conglomerate of southern Tibet and its tectonic significance

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Progress in Natural Science:Materials International 2006年第1期16卷 55-64页

作者： FANG Aimin1, YAN Zhen1, LIU Xiaohan2. PAN Yusheng1, LI Jiliang1, YU Liangjun1, HUANG Feixing2.and TAO Junrong3 (1.Laboratory of Lithosphere Tectonic Evolution, institute of Geology and geophysics, Chinese Academy of Sciences,{2. 10002., China 2. institute of Tibet Plateau Research, Chinese Academy of Sciences, beijing 100085, China 3. institute of Botany, Chinese A cademy of Sciences,{2. 100093, China) Laboratory of Lithosphere Tectonic Evolution Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China institute of Tibet Plateau Research Chinese Academy of Sciences Beijing 100085 China institute of Botany Chinese A-cademy of Sciences Beijing 100093 China

The Liuqu Conglomerate, situated to the south of Yarlung Tsangbo Suture Zone (YTSZ), is a suit of molasse formed in a foreland basin of the Himalayan orogenic belt after the collision between the two plates of the Indian and Eurasion, It is of great significance in constraining the younger limit time of the collision of the two plates and providing stratigraphic evidence to reveal the post-colli sional tectonic evolution and uplifting history of the Tibet plateau. However, the age of this molasse suit and its correlation to other synchronous strata distributed in southern Tibet have been in great disputes for a long time. Especially in recent years, argues on its ages are growing violently with the recognition of the great sedimentary tectonic significances of this molasse. During the field work carried out recently on this molasse suit, a lot of plant fossils were found preserved in fairly good conditions in the upper part of this strata, which is of great help in determining its age. By identification, the assemblage of the plant fossils belongs to a tropic to subtropic flora developed in the southern margin of the Northern Hemisphere supercontinent during the Middle to Later Eocene, which can provide good constraint on its formation age. This paper is to give a brief introduction of the plant assemblage and its age, and to discuss their tectonic significances.

关键词： Liuqu conglomerate plant fossils age Eocene Tectonic implications.

A preliminary study on seismic design criteria of offshore platforms in Bohai Sea of China

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Earthquake Engineering and Engineering Vibration 2010年第2期9卷 223-231页

作者： Peng Yanju1,Lu Yuejun1,Yan Jiaquan2.Tang Rongyu1,Wang Junqin3 and Li Jiagang3 1. institute of Crustal Dynamics,China Earthquake Administration,beijing{2.,China 2. institute of geophysics,China Earthquake Administration,beijing 100081,China 3. beijing Research Center of China National Offshore Oil Corp.,beijing 10002.,China institute of Crustal Dynamics China Earthquake Administration Beijing 100085 China

This paper analyzes the seismicity in Bohai Sea,introducing a shape factor K to characterize the seismic risk distribution in sub-regions of the sea. Based on the seismic design ground motions for 46 platforms located in the Bohai Sea,a statistical analysis was performed for different peak ground acceleration (PGA) ratios at two different probability levels. In accordance with the two-stage design method,a scheme of two seismic design levels is proposed,and two seismic design objectives are established respectively for the strength level earthquake and the ductility level earthquake. By analogy with and comparison to the Chinese seismic design code for buildings,it is proposed that the probability level for the strength level earthquake and ductility level earthquake have a return period of 2.0 and 1000 - 2.00 years,respectively. The validity of these proposed values is discussed. Finally,the PGAs corresponding to these two probability levels are calculated for different sub-regions of the Bohai Sea.

关键词： fixed offshore platform seismic design level seismic design objective return period Bohai Sea

Geophysical and Geological Features of the Meso-Cenozoic Lower Yangtze Rift Zone

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Acta Geologica Sinica(English Edition) 1990年第4期64卷 363-378页

作者： Chen Shengzao institute of geophysics, State{2. bureau, beijing Zhu Lupei institute of geophysics State Seismological Bureau Beijing

It is clarified in this paper that the Lower Yangtze depression is a Meso-Cenozoic rift zone formed on thebasement of the Hercynian-Indosinian foreland basins. The rift zone is divided into eastern and western sectorsand is different in northern and southern parts. The rift zone in plane combination comprises *** or splitting rifts. The North Jiangsu-South Yellow Sea region represents a 'drift-type' rift basinwhose deposition center migrates gradually castward. The formation mechanism and dynamic evolution of therift basin are discussed from a viewpoint of the crustal fine-structure, with evidence in geology and geophysicsand analysis results of dynamic forces given.

关键词： Geophysical and Geological Features of the Meso-Cenozoic Lower Yangtze Rift Zone

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

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Acta Geologica Sinica(English Edition) 1995年第3期69卷 223-239页

作者： Chen Shengzao institute of geophysics, State{2. bureau, beijing institute of geophysics State Seismological Bureau Beijing

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 in the superposition of various types of mineral deposits; seismic activities and metallogeny are mutually inducing factors. These views will be helpful to a discussion on the tectonic environments and metallogenic regularities.

关键词： deep structure tectonic environment metallogeny

Earthquake Resistant Engineering and Application of Seismic Zonation Map of ChinaTechnicalInnovations

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Engineering Sciences 2004年第2期 76-81页

作者： Shi Zhenliang 1, Li Yuche 2. Zhang Xiaodong 1 (1. institute of geophysics, China{2. bureau, beijing 100081 2. S & T Commission, China{2. bureau, beijing 100036)

China is a country with high seismicity. It is very important for industry and structure to fortify against earthquakes. In this paper the outline of seismicity in China, the criteria for fortification against earthquakes and the contents of seismic zonation map of China are described. The contents of seismic safety evaluation for major construction projects, such as large dams, large bridges, long distance pipe lines for transporting oil and natural gas, nuclear plants, petrochemical enterprises and so on, are presented. Some geological disasters caused by destructive earthquake, such as earthquake caused collapse and landslide, liquefaction of saturated soil and earthquake fault and so on, are also presented. Preventive countermeasures for these disasters are discussed.

关键词： seismic zonation earthquake resistant engineering earthquake caused geological disaster