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Distribution characteristics of magnetic susceptibility of the surface sediments in the southern Yellow Sea

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chinese Science Bulletin 2003年第B6期48卷 37-41页

作者： GE Shulan~(1,2,3), SHI Xuefa~1 & HAN Yibing~1 1. Key Laboratory of Marine Sedimentology and Environmental geology, First institute of Oceanography, State Oceanic Administration. Qingdao 266061. china 2. institute of geology and geophysics, chinese academy of sciences, beijing 100029. china 3. Graduate School. chinese academy of sciences, beijing 100039. china Key Laboratory of Marine Sedimentology and Environmental geology First Institute of Oceanography State Oceanic Administration Qingdao China institute of geology and geophysics Chinese Academy of Sciences Beijing China Graduate School Chinese Academy of Sciences Beijing China

The characteristic distributions of magnetic susceptibility (MS) are analyzed on the basis of susceptibility of 172 surface sediment samples in the southern Yellow Sea (SYS). The preliminary results are as follows: first, the distributions clearly correspond to different modern sediment assemblages in the continental sea, which indicates different sediment origins. With the 30 μCGS isoline being taken as demarcation line, the study area can then be divided into section H (high MS value area) and section L (low MS value area). Section H is mainly adjacent to land with two main sources of the Changjiang River and the Huanghe *** L is mainly an eddy sediment area, where Yellow Sea Cold Water is entrenched all the year round. The distribution pattern of MS could tell apart strong or weak hydrodynamic conditions and has a close relation to the circulation system in this area. At the areas of the SYS Circumfluent and northern East china Sea (NECS) Circumfluent (weak hydrodynamic), the MS has low values, while in the areas of Coastal Current (strong hydrodynamic), the values are *** the same time, the oxidizing areas tend to take on higher MS, while the reducing areas have lower one. It seems safe to say that the MS in the continental sea reflects more of the sediment origin and sedimentary environment, which is different from that of loess, lake and surface soil as a climate proxy.

关键词：中国黄海表面沉积物磁化率等值线长江黄河旋涡沉积区循环系统

CENOZOIC LARGE-SCALE STRIKE-SLIP FAULT IN WEST YUNNAN, china

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地学前缘 2000年第S1期7卷 268-269页

作者： Ji Jianqing 1, Zhong Dalai 2, Sang Haiqing 2, Zhang Liansheng 2[WT5,5”BX](1 Department of geology, Peking University, beijing 100871,china 2.institute of geology and geophysics, chinese academy of sciences, beijing 100029,china)

During the collision between India and Eurasia, the continental compression and shorten is thought to be absorbed by the way of thickening of the Tibetan plateau crust and strike\|slip extrusion outwardly of blocks surrounding the Tibetan plateau. A series of models have been proposed recently, of which the most typical one is continental blocks extrusion by Tapponnier et al.. Virtually previous studies show that the Red River—Ailaoshan fault is the eastern boundary of extrusion Indochina displaced southward relative to South china about 23 Ma ago, and more, the western boundary of extrusion blocks is inferred to be Sijie fault in the eastern Burma. But the movement age of Sijie fault is around 13 Ma inferred from the age of Andeman Sea formation and different from that of the Red River—Ailaoshan fault. It is an important scientific problem where the western boundary of extrusion blocks is.

关键词： the western boundary of extrusion blocks Cenozoic dextral strike\|slip fault deformation age West Yunnan

Structural pattern of eastern Himalayan syntaxis in Namjagbarwa and its formation process

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Science china Earth sciences 2004年第2期47卷 138-150页

作者： ZHANG Jinjiang, Jl Jianqing, ZHONG Dalai, DING Lin & HE Shundong1. Department of geology, Peking University, beijing 100871, china 2. institute of geology and geophysics, chinese academy of sciences, beijing 100029, china Correspondence should be addressed to Zhang Jinjiang (email: zhjj@***) Department of geology Peking University Beijing China institute of geology and geophysics Chinese Academy of Sciences Beijing China

The structural pattern of the eastern Himalayan syntaxis in Namjagbarwa consists of two series of structures with different styles. One series compiles the earlier ductile contractional and lateral-slip deformation system, formed by nearly north-south shortening within the syntaxis, left-lateral and right-lateral slipping along its western and eastern boundaries respectively. They were possibly produced by the indentation of the Indian continent into Asian continent after India-Asia collision. The peak deformation-metamorphic ages in these structures are 62-60 Ma, ~23 Ma and ~13 Ma. The other series is composed of ductile-brittle normal faults distributing concentrically and dipping toward the outsides of Namjagbarwa Peak. They were probably the collapse structures caused by rapid uplift in a later time and the beginning ages for the normal faulting are about 7.3-6.3 Ma. Keywords Namjagbarwa - eastern Himalayan syntaxis (EHS) - structural pattern - formation process - structural chronology

关键词： Namjagbarwa, eastern Himalayan syntaxis (EHS), structural pattern, formation process, structural chronology.

MULTI-PERIODIC COLLISIONAL PROCESS BETWEEN INDIAN AND ASIAN CONTINENTS:A CASE OF EASTERN HIMALAYAN SYNTAXIS AND HENGDUAN MOUNTAINS

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地学前缘 2000年第S1期7卷 47-48页

作者： Zhong Dalai 1, Ding Lin 1, Zhang Jinjiang 1, Ji Jianqing 2(1 institute of geology and geophysics, chinese academy of sciences, beijing 100029, china 2 Department of geology, Peking University, beijing 100871, china)

Our study area covered the Eastern Himalayan Syntaxis (EHS) and its southern extension (Hengduan Mountain or western Sichuan and Yunnan (WSY)) which is located at the orthogonal and oblique collisional front between Indian and Asian continents during *** on geometric and kinematic mapping of the major boundary or regional faults (Dongjug—Mainling(1), Anigiao(2) and Jali(3), Guyu(4) faults in EHS, Ailaoshan—Red River(5), Lancangjiang(6), Gaoligong(7), Binlangjiang(8) and Magok(9) faults in WSY) (see Fig.1), especially on abundant geochronological dating of the mylonitic rocks along these faults, and coupled with magmato\|metamorphic sequences of this region, we try to deal with the temporal and spatial relationships of collisional process to answer questions such as: (1) when did collision start ? (2) is thrusting as a initial and dominant deformation mode to absorb the crustal shortening after suturing, or earlier thrusting usually followed by large\|scale strike\|slip faults? (3) are the two structural patterns coeval at times, or do they occur alternatively during deformation history? (4) are the collisional and associate uplift processes a continuous one or periodic? Insight into such questions is crucial for better understanding of the continental deformation and testing the models available or constraining a new one.

关键词： collisional process multi\|period tectonic events Eastern Himalaya

Project research of GIS data based on AutoCAD

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中国有色金属学会会刊：英文版 2005年第S1期15卷 244-246页

作者： YAO Xin ~(1, 2) (1. institute of geology and geophysics, chinese academy of sciences, beijing 100029, china 2. The Geomatics and Applications Laboratory, Liaoning Technical University, Fuxin 123000, china) chinese Acad Sci Inst Geol & Geophys Beijing 100029 Peoples R China Liaoning Tech Univ Geomat & Applicat Lab Fuxing 123000 Peoples R China

The digitalization software developed based on AutoCAD is one important platform of GIS data gather. But because AutoCAD itself is not the software of GIS, it can not be used to collect the attribute data. And conversion data to GIS software often lose some information such as color, line style, symbol shape. By using the XDATA, the Handle, the Group of AutoCAD and the provided ObjectArx to Redevelop, under AutoCAD condition, the attribute information collection with space information were realized, also did the AutoCAD symbol integrity and accurate expresses, then the demand of the digit graphics was satisfied.

关键词： AutoCAD attribute data data transfer ObjectArx XDATA

Carbon isotope ratios of C_(4) plants in loess areas of North china

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Science china Earth sciences 2006年第1期49卷 97-102页

作者： WANG Guoan1,2,3, HAN Jiamao 2, ZHOU Liping3, XIONG Xiaogang4, TAN Ming2, WU Zhenhai5 & PENG Jun6 1. Department of Plant Nutrition, china Agricultural University, beijing 100094, china 2. institute of geology and geophysics, chinese academy of sciences, beijing 100029, china 3. College of Environmental sciences, MOE Laboratory for Earth Surface Processes, Peking University, beijing 100871, china 4. institute of Botany, chinese academy of sciences, beijing 100093, china 5. Northwest Sci-Tech University of Agriculture and Forestry, Yangling 712100, china 6. Network Center, china Agricultural University, beijing 100094, china Department of Plant Nutrition China Agricultural University Beijing China institute of geology and geophysics Chinese Academy of Sciences Beijing China College of Environmental sciences MOE Laboratory for Earth Surface Processes Peking University Beijing China institute of Botany Chinese Academy of Sciences Beijing China Northwest Sci-Tech University of Agriculture and Forestry Yangling China Network Center China Agricultural University Beijing China

Carbon isotope ratios (δ^(13)C) of 89 C_4 plant samples were determined fromthe loess area in North china. δ^(13)C values vary between -10.5per thousand and -14.6per thousandwith a mean of -12.6per thousand. Along a precipitation gradient from the semi-moist area to thesemiarid area, then to the arid area, the δ^(13)C values of C_4 plants show a slight decreasingtrend. The δ^(13)C values of C_4 plants in the dry season are found lower than those in the wetseason. These trends are opposite to those observed for C_3 species.

关键词： C4 plants, carbon isotope ratios, loess area.

Crust and uppermost mantle structure of the Ailaoshan-Red River fault from receiver function analysis

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Science china Earth sciences 2006年第10期49卷 1043-1052页

作者： XU Mingjie1, WANG Liangshu1, LIU Jianhua2, ZHONG Kai1, LI Hua1, HU Dezhao1 & XU Zhen1 1. Department of Earth sciences, Nanjing University, Nanjing 210093, china 2. institute of geology and geophysics, chinese academy of sciences, beijing 100029, china Department of Earth sciences Nanjing University Nanjing China institute of geology and geophysics Chinese Academy of Sciences Beijing China

S-wave velocity structure beneath the Ailaoshan-Red River fault was obtained from receiver functions by using teleseismic body wave records of broadband digital seismic stations. The average crustal thickness, Vp/Vs ratio and Poisson’s ratio were also estimated. The results indicate that the interface of crust and mantle beneath the Ailaoshan-Red River fault is not a sharp velocity discontinuity but a characteristic transition zone. The velocity increases relatively fast at the depth of Moho and then increases slowly in the uppermost mantle. The average crustal thickness across the fault is 36―37 km on the southwest side and 40―42 km on the northeast side, indicating that the fault cuts the crust. The relatively high Poisson’s ratio (0.26―0.28) of the crust implies a high content of mafic materials in the lower crust. Moreover, the lower crust with low velocity could be an ideal position for decoupling between the crust and upper mantle.

关键词： receiver function, Ailaoshan-Red River fault, velocity structure, Poisson's ratio, crust and upper mantle.

Ultramafic xenoliths in Mesozoic diorite in west Shandong Province

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Science china Earth sciences 2004年第6期47卷 489-499页

作者： CHEN Lihui1,2 & ZHOU Xinhua2 1.The Key Laboratory of Orogenic Belts and Crustal Evolution,Ministry of Education,china and School of Earth and Space sciences,Peking University,beijing 100871,china 2.institute of geology and geophysics,chinese academy of sciences,beijing 100029,china Correspondence should be addressed to Chen Lihui(email: lihui_chen@***) The Key Laboratory of Orogenic Belts and Crustal Evolution Ministry of Education China and School of Earth and Space Science Peking University Beijing China institute of geology and geophysics Chinese Academy of Sciences Beijing China

Ultramafic xenoliths are common in Tietonggou intrusion, Laiwu, Shandong Prov-ince. Peridotite xenoliths develop two-stage metasomatism popularly: (i) The early metasoma-tism is characterized by intergranular clinopyroxene and phlogopite; (ii) The later metasomatism is characterized by orthopyroxene veins with a few plagioclases and amphiboles. These ul-tramafic xenoliths are thought to be mostly from the crust-mantle transitional zone on the basis of their combination, mineral chemistry, equilibrium temperature, and metasomatic characteristics. Major elements, rare earth elements, and Sr-Nd isotopic composition of the ultramafic xenoliths indicate that there is a petrogenetic relationship between the silica-enriched xenoliths and their host diorites. We propose that such silica enrichment might be an indicator of melt-rock interac-tions in the Mesozoic lithosphere beneath western Shandong.

关键词： ultramafic xenoliths, crust-mantle transitional zone,metasomatism, Tietonggou intrusion, Laiwu.

Sulfur and carbon isotopic variations in Neoproterozoic sedimentary rocks from southern china

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Progress in Natural Science:Materials International 2003年第11期 75-80页

作者： CHU Xuelei 1,2*, ZHANG Qirui 1, ZHANG Tonggang 1,2 and FENG Lianjun 1,2(1. institute of geology and geophysics, chinese academy of sciences, beijing 100029, china 2. Key Laboratory for Mineral Resources Research, chinese academy of sciences, beijing 100029, china) institute of geology and geophysics，chinese academy of sciences，beijing 100029，china Key Laboratory for Mineral Resources Research，chinese academy of sciences，beijing 100029，china institute of geology and geophysics，chinese academy of sciences，beijing 100029，china

A new set of δ 34S sulfide, δ 34S sulfate and δ 13C carbonate values has been reported from Neoproterozoic sedimentary rocks in southern china. The interglacial black shales of the Datangpo Fm. display higher δ 34S sulfide values with >+20‰ average, but the postglacial black shales from the Doushantuo Fm. show negative δ 34S sulfide values. However, the Jinjiadong Fm., the same post-glaciation as the Doushantuo Fm., has positive δ 34S sulfide values, implying that the δ 34S value of sedimentary sulfides would be controlled by lithofacies and paleogeographic environments. The δ 34S sulfate values relative to δ 13C carbonate were obtained by extraction of trace sulfate from the successive carbonate sequences in the Yangtze Gorges sections. A preliminary interpretation suggests that the oceanic environment may fluctuate dramatically at the post-glacial Doushantuo stage and, then, recover its stability at the Dengying stage on the basis of the high resolution δ 34S and δ 13C curves of seawater.

关键词： Neoproterozoic southern china sulfur isotopes carbon isotopes seawater secular variations.