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Science china Earth sciences 2004年第2期47卷 181-192页

作者： li zhong, liu shaofeng, zhang jinfang & wang qingchen1. institute of geology and geophysics, chinese academy of sciences, beijing 100029, china 2. china University of Geosciences, beijing 100083, chinaCorrespondence should be addressed to li zhong (email: lizhongd@***) 1. institute of geology and geophysics Chinese Academy of Sciences 100029 Beijing China 2. china University of Geosciences 100083 Beijing China

Basin-fill sequences of Mesozoic typical basins in the Yanshan area, North china may be divided into four phases, reflecting lithosphere tectonic evolution from flexure (T3), flexure with weak rifting (J1+2), tectonic transition (J3), and rifting (K). Except the first phase, the other three phases all start with lava and volcaniclastic rocks, and end with thick coarse clastic rocks and/or conglomerates, showing cyclic basin development rather than simple cyclic rift mechanism and disciplinary basin-stress change from extension to compression in each phase. Prototype basin analysis, based on basin-fill sequences, paleocurrent distribution and depositional systems, shows that single basin-strike and structural-line direction controlling basin development had evidently changed from east-west to northeast in Late Jurassic in the Yanshan area, although basin group still occurred in east-west zonal distribution. Till Early Cretaceous, main structural-line strike controlling basins just turned to northeast by north in the studied area.

关键词： Yanshan, Mesozoic, basin-fill, paleocurrent, tectonic transition.

Magma underplating and Hannuoba present crust-mantle transitional zone composition: Xenolith petrological and geochemical evidence

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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, beijing 100029, china 2. institute of geology, china Seismological Bureau, beijing 100029, 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 Bureau, beijing 100029, china 2. institute of geology and geophysics, chinese academy of sciences, beijing 100029, 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_2O+Na_2O = 5%—11%, especially for K_2O) as well asvolatiles such as H_2O 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_2O > 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.

Paleomagnetic study on orogenic belt:An example from Early Cretaceous volcanic rocks,Inner Mongolia,china

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Science china Earth sciences 2004年第12期47卷 1127-1133页

作者： REN Shoumai 1,2 ,ZHU Rixiang 1 ,HUANG Baochun 1 ,zhang Fuqin 1 & wang Hongqiang 1 1.institute of geology and geophysics,chinese academy of sciences,beijing 100029,china 2.Strategic Research Center for Oil and Natural Gas,The Ministry of Land and Resources of china,beijing 100034,china 1. Strategic Research Center for Oil and Natural Gas The Ministry of Land and Resources of China 100034 Beijing China 2. chinese academy of sciences Institute of Geology and Geophysics 100029 Beijing China

We report paleomagnetic results for Early Cretaceous lava flows collected from the Suhongtu area of Inner Mongolia, the middle part of the Tianshan-Mongolia Fold Belt (TMFB). Rock-magnetic experiments for different lava flows indicate that the main magnetic mineral is pseudo-single-domain (PSD) magnetite. The characteristic high-temperature remanence com- ponent is isolated by thermal demagnetization temperature steps between 300°C and 585"C, which yields a mean direction of D = 23.6°, I=56.0° with α 95 = 2.3°. We interpret this high-temperature remanence component as primary magnetization based mainly upon the petrographic analysis, which shows that the shape of magnetite crystal is relatively rounded square or polygon without internal reflection and deuterogenous phenomenon. The correspond- ing pole of the high-temperature remanence component is at 71.1°N, 200.5°E with A 95 = 2.7°. This Early Cretaceous pole is in good agreement with those for Siberia, North china, and Inner Mongolia, suggesting that these continental blocks had already sutured together in the Early Cretaceous, which would further provide constraints on better understanding of the formation and evolution of the TMFB.

关键词： orogenic belt, paleomagnetism, Suhongtu of Inner Mongolia, Eurasia.

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, beijing 100029, china 2. institute of geophysics, chinese Seismological Bureau, beijing 100081, china 3. institute of Deposition Resource, chinese academy of Geological sciences, beijing 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

Principles and methods of quantitative analysis on b-axis disorder in 2 : 1 dioctahedral phyllosilicate

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chinese Science Bulletin 1997年第22期42卷 1908-1912页

作者： wang ling and zhang Zhenyu1. Changsha institute of Geotectonics, chinese academy of sciences, Changsha 410013, china 2. institute of geology, chinese academy of sciences, beijing 100029, china Changsha institute of Geotectonics Chinese Academy of Sciences Changsha China institute of geology Chinese Academy of Sciences Beijing China

IN XRD patterns of clay minerals, a phenomenon that strong peaks often have (00l) and(hkl) (k=3n) indices and show symmetric figures can be seen commonly, while a minorityof reflection peaks (hkl) (k≠3n) are comparat... 详细信息

关键词： b-axis disorder pyrophvllile 2 phyllosilicate clay minerals dioctahedral minerals orientating structure of hy-droxyls crystal structure analysis DTA-TG.

Co-seismic ground deformation and source parameters of Mani M7.9 earthquake inferred from spaceborne D-InSAR observation data

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Science china Earth sciences 2004年第6期47卷 481-488页

作者： SHAN Xinjian1,MA Jin1,wang Changlin2,liu Jiahang1,SONG Xiaoyu1 & zhang Guifang1 1.institute of geology and Laboratory of Tectonophysics,china Seismological Bureau,beijing 100029,china 2.institute of Remote Sensing Application,chinese academy of sciences,beijing 100101,china 1. institute of geology and Laboratory of Tectonophysics China Seismological Bureau 100029 Beijing China 2. institute of Remote Sensing Application Chinese Academy of Sciences 100101 Beijing China

We obtain the co-seismic ground deformation field of the Mani M7.9 earthquake on November 8, 1997 through three-pass differential interferometric processing. Then we get the geometric and kinematics parameters of this event by the elastic half-space model and forward modeling with the InSAR data. The following results have been obtained: (i) The deformation fields on both sides of the seismogenic fault are affected by the co-seismic deformation field even in 110 km away from the fault. The loss of phase coherence belt caused by the zone of ground rupture crosses the image from east to west with a length of an area 110 km. (ii) The maximum horizontal displacement caused by the earthquake reaches 7.96 m. (iii) The earthquake fault can be divided into four parts, and the deformation field of the middle two parts is bigger than that of the other two, with lengths of 27 km and 37 km, respectively. And their average sliding values on the rupture surface are 6500 mm and 6000 mm, respectively, and their depths both are 35 km. The segment of 27 km length is the major rupture surface of this earthquake. The west part and the east part of the fault have lengths of 23 km and 26 km, respectively. The sliding value of the west one is 4000 mm and that of the east one is 5800 mm. They extend to depths of 20 km and 18 km, respectively.

关键词： D-InSAR, surface deformation field in sight direction, Mani earthquake, characteristics of earthquake fault.

Jinning granodiorite and diorite deeply concealed in the central Tarim Basin

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Science china Earth sciences 2005年第12期48卷 2061-2068页

作者： li Yuejun1, 2, SONG Wenjie2, WU Genyao1, wang Yifen1, li Yuping2 & ZHENG Duoming2 1. institute of geology & geophysics, chinese academy of sciences, beijing 100029, china 2. Tarim Oil-field Company, Petrochina, Korla 841000, china 1. institute of geology & geophysics Chinese Academy of Sciences 100029 Beijing China 2. Tarim Oil-field Company 841000 Korla PetroChina China

The 7200-m-deep Well Tacan 1 in the central Tarim Basin is the deepest in china. Purplish gray medium-grained granodiorite containing dark gray fine-grained diorite xenolith is revealed at the base of the well (7169―7200 m), and they are results of the Jinning magmatic activities. Trace-element geochemistry and REE profiles of both rock types are similar, indicating that they are calc-alkaline series I-type granitoid. Proxies of diorite signify the development of a magmatic arc due to subduction at ca. 1200 Ma. The granodiorite was formed before 890―932 Ma. However, more study is needed to clarify if the arc diorite represents a ca. 300 Ma extension of the subduction or a reactivation during the orogenic collision event at ca. 900 Ma.

关键词： diorite, granodiorite, magmatic arc, Jinning orogeny, Tarim Basin.

Experimental investigation and numerical simulation on the effect of fissure water pressure in vertical sliding surface

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Science china(Technological sciences) 2005年第z1期48卷 53-64页

作者： zhang Lei1,2, li Shihai1, liAN Zhenzhong1,2 & wang Yuannian1 1. institute of Mechanics, chinese academy of sciences, beijing 100080, china 2. Graduate School, chinese academy of sciences, beijing 100060, china 1. institute of Mechanics Chinese Academy of Sciences 100080 Beijing China 2. Graduate School Chinese Academy of Sciences 100060 Beijing China

This paper studies the effect of fissure water pressure in different fractures on the critical angle of landslide by laboratory investigation and numerical simulation in order to understand the mechanisms of fissure water pressure on landslide stability. Laboratory observations show that the effect of fissure water pressure on the critical angle of landslide is little when the distance between water-holding fracture and slope toe is three times greater than the depth of fissure water. These experimental results are also simulated by a three-dimensional face-to-face contact discrete element method. This method has included the fissure water pressure and can accurately calculate the critical angle of jointed slope when fissure water pressure in vertical sliding surface exists. Numerical results are in good agreement with experimental observations. It is revealed that the location of water-holding structural surface is important to landslide stability. The ratio of the distance between water-holding fissure and slope toe to the depth of fissure water is a key parameter to justify the effect of fissure water pressure on the critical angle of landslide.

关键词： jointed rock slope, discrete element method, fracture in vertical sliding surface, model experiment,fissure water pressure.