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Study on High Cutting Slopes with Horizontal Soft-hard Strata in Three Gorges Reservoir Area

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Study on High Cutting Slopes with Horizontal Soft-hard Strat...

中国科学院地质与地球物理研究所第11届（2011年度）学术年会

作者： Guoxiang Yang~(1,a),Jinyu Dong~(2,b),Faquan wu~(1,c),Dong Wang~(1,d), Jihong Yang~(2,e) 1 Institute of geology and geophysics,chinese academy of sciences Key Laboratory of Geomechanics,Institute of geology and geophysics,chinese academy of sciences beijing 10002.,china 2 North china University of Water Resources and Electric Power,Zhengzhou 450011,china

High cutting slopes with nearly horizontal soft-hard alternant strata are widely distributed in three gorges reservoir area,the soft and hard rocks are mainly mud stone and sandstone of Jurassic *** failure of this kind of slope is also the main geo-hazards in this ***,this paper analyzed the impact of topography,water as well as the differential weathering and combination characteristics of soft and hard rocks *** the sliding failure of slopes;secondly, sliding failure modes of this kind of slope were classified into four types including circular sliding, sliding along the extroversion structural surface,sliding along the mudded intercalation and wedge sliding,they were analyzed combined with case *** lastly,support methods against the certain failure mode were put *** research results are significant to the support and treatment of high cutting slopes in Three gorges area.

关键词： high cutting slope soft-hard alternant strata sliding failure mode protection measures

Mechanism of deep cracks in the left bank slope of Jinping first stage hydropower station

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Mechanism of deep cracks in the left bank slope of Jinping f...

中国科学院地质与地球物理研究所2004学术年会

作者： Qi Shengwen~(a,*),wu Faquan~a,Yan Fuzhang~a,Lan Hengxing~b a Engineering Geomechanics Laboratory,Institute of geology and geophysics,chinese academy of sciences, P.O.Box 9825,beijing 10002.,PR china b LREIS,Institute of Geographical sciences and Natural Resource Research,chinese academy of sciences,beijing 100101,PR china

The proposed Jinping first stage hydropower station is located on the middle reach of the Yalongjiang River,Sichuan Province,PR *** consists of a double-curvature arch dam with a maximum height of 305 m,which will be the highest in the *** are well developed in the left bank slope of the Pusiluogou,the dam site of Jinping first stage hydropower station. Some cracks are even developed at the horizontal distance into rock face(in this paper,the term"horizontal depth"was used to describe the horizontal distance into face of the slope) beyond 200 m,and these cracks are here referred to as deep *** distribution of these deep cracks is far beyond people’s experiences in common unloading zones,so the mechanism of the deep cracks is put forward as a new *** cracks are significant for the stability of the slope,their mechanism becomes one of the key engineering geology problems.A comprehensive study is made in this paper on the distribution characteristics of the cracks as well as their deformation *** factors that influence their distribution and deformation feature are also analyzed by means of geology,mechanics and numerical *** important conclusion is consequently reached that deep cracks occurred as a result of release of high ground stress including gravitational stress and tectonic *** formation of the deep cracks in the slope is a result of unloading process under favorable geology *** crust uplift and quick river cutting and high tectonic stress are indispensable regional geological condition,steep and high geometry condition provides favorable geometry condition,hard at the lower part and soft at the upper part of the slope offers suitable rock combination condition,and back facing bending planes and consequent discontinuities supply suitable structure of the slope.

关键词： Jinping first stage hydropower station Deep cracks Mechanism Unload

Study on kinetics of hydrocarbon generation from coals in the Qinshui Basin

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Science Bulletin 2005年第17期 90-97页

作者： DUAN Yi1, wu Baoxiang1,3, ZHENG Chaoyang1,3, WANG Chuanyuan1,3, ZHANG Hui1, TAO Mingxin1, LIU Jinzhong2 & ZHANG Xiaojun1,3 1. Institute of geology and geophysics, chinese academy of sciences, Lanzhou 730000, china 2. Guangzhou Institute of Geochemistry, chinese academy of sciences, Guangzhou 510640, china 3. Graduate School of chinese academy of sciences, beijing 100039, china

A new method for the quantitative assessment of hydrocarbon generation potential from coals by means of the chemical reaction kinetics has been developed gradually over the recent years. In this paper, the kinetic parameters of hydrocarbon gas generation are determined by high tem-perature and pressure, and closed- system thermal simula-tion for Late Paleozoic coals in the Qinshui Basin and the kinetic characteristics and the histories of hydrocarbon gas generation were studied using the parameters obtained. Re-sults show that during the longer period from the Triassic (T) to the Middle Jurassic (J2), the coal-derived methane yield increased more slowly under lower palaeogeotemperature in the Qinshui Basin; however, the shorter period from Late Jurassic to Early Cretaceous, the coal-derived methane yield increased more rapidly under higher palaeogeotemperature. The correlation between the thermal simulation and the fac-tual data shows that C1/ (C1+C2―4) coefficients computed by the histories of methane and C2―C4 hydrocarbon generation can provide evidence for the identification of the genesis of coal bed gas in the different areas of the Qinshui Basin. The kinetic simulating experiment of hydrocarbon generation for the peat considered as the original matter of coal formation was performed for the first time and the simulated results were compared with the characteristics of hydrocarbon gen-eration from coals undergoing various palaeogeotemperature in the Qinshui Basin. The result indicates that the peat has a higher potential of hydrocarbon generation than that of coals. Therefore, the hydrocarbon generation results obtained from kinetic simulation for coal with higher maturation rank could not stand for their original hydrocarbon generation potential and thus would lead to an underestimation for coal-bed gas resource. The generative amount of coal-derived gas in the Qinshui Basin was predicted using kinetic simula-tion results for the peat and their maximum was est

关键词： Qinshui Basin hydrocarbon generation of coal kinetic simulation prediction for the amount of coal-derived gas generation.

Neoproterozoic(～900 Ma) Sariwon sills in North Korea:Geochronology,geochemistry and implications for the evolution of the south-eastern margin of the North china Craton

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Neoproterozoic(～900 Ma) Sariwon sills in North Korea:Geochr...

中国科学院地质与地球物理研究所第11届（2011年度）学术年会

作者： Peng Peng~(a,b,*),Ming-Guo Zhai~(a,b),Qiuli Li~a,Fuyuan wu~a,Quanlin Hou~c,Zhong Li~a, Tiesheng Li~a,Yanbin Zhang~a a State Key Laboratory of Lithospheric Evolution,Institute of geology and geophysics,chinese academy of sciences,beijing 10002.,china b Key Laboratory of Mineral Resources,chinese academy of sciences,beijing 10002.,china c Graduate University of chinese academy of sciences,beijing 100039,china

The Sariwon sills are distributed in the Pyongnam basin at the center of the Korean peninsula,eastern part of the North china *** sills are up to 150 m in thickness and up to more than 10 km in length. Baddeleyite grains separated from a～50 m thick sill give a SIMS Pb-Pb age of 899±7 Ma (MSWD = 0.34,n = 14),which is interpreted to be the crystallization age of this *** grains from the same sill gives a lower intercept U-Pb age of～400 Ma,which is likely a close estimation of the greenschist-facies metamorphism of this *** Sariwon sills are dolerites and have tholeiitic *** show enrichment of light rare earth element concentrations(La/Yb= 1.4-2.8) and are slightly depleted in high field strength elements(***,Zr,and Ti),in comparison to neighboring elements on the primitive-mantle normalized *** whole rock sNd(t = 900 Ma) values are around - 2,whereas in-situεHf (t = 900 Ma) values from zircon grains vary from - 25 to + *** are similar to the coeval sills in other parts of the North china Craton,e.g.,the Chilian sills(Xu-Huai basin,Shandong peninsula) and the Dalian sills(Lv-Da basin,Liaodong peninsula).These sills possibly originated from a depleted mantle source(e.g., asthenosphere),rather than from the ancient lithospheric mantle of the North china Craton,and have experienced significant assimilation of lithospheric *** strata and sills in the Xu-Huai,Lv-Da and Pyongnam basins are comparable;moreover the three basins are geographically correlatable based on Neoproterozoic geographical *** therefore propose that there is a Xu-Huai-Lv-Da-Pyongnam rift system along the south-eastern edge of the North china Craton during Neoproterozoic(～900 Ma),with the closure of the rift at～400 Ma as a result of a continent-margin *** is possible that this southeastern margin of the NCC did not face the inland in the configuration of the supercontinent Rodinia.

关键词： North china Craton Neoproterozoic Korean peninsula Sill and dyke Rodinia supercontinent

THRUST TECTONICS AND RELATED CROSS-SECTION BALANCING IN THE SOUTHWESTERN FUJIAN FORELAND FOLD AND THRUST BELT

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Scientia Geologica Sinica 2000年第2期 151-158页

作者： wu Yungao and Li Jiliang (Laboratory of Lithosphere Tectonic Evolution, Institute of geology and geophysics chinese academy of sciences, beijing 10002.) Lu Huafu and Jia dong (Department of Geosciences, University of Nanjing Nanjing 210093)

On the basis of the data made by former geological researchers and our own studies, the thrust and nappe tectonics, widely found in the Mesozoic Southwestern Fujianforeland fold and thrust belt, can be classified into two types :①cover thrust sheets, ②basement thrust sheets, also called C-type thrust sheets (i.e. Composite thrust sheets). The main structural styles developed in the this belt include stepped thrust fault and fault-related fold such as fault-bend fold, imbricate fan and duplex, klippe and window,and back thrust. The main thrust direction was from SE to NW. Two typical balanced cross-sections and their restored ones are presented in the paper. The authors think that the mie shortened distance of the Southwestern Fujianforeland fold and thrust belt is between 47.7km and 170km, and the true shortened rate is between 25% and 54%.

关键词： In THRUST TECTONICS AND RELATED CROSS-SECTION BALANCING IN THE SOUTHWESTERN FUJIAN FORELAND FOLD AND THRUST BELT AL

Key points model for polar region currents

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Key points model for polar region currents

中国科学院地质与地球物理研究所2008学术年会

作者： Wen-Yao Xu,Geng-Xiong Chen,Ai-Min Du,Ying-Yan wu,Bo Chen, and Xiao-Can Liu 1 Institute of geology and geophysics,chinese academy of sciences, beijing,china.

[1]The equivalent ionospheric electric currents in the polar region mainly consist of the DP1 and DP2 *** former involves a westward electrojet around midnight,while the later involves a two-cell system with foci on the morningside and eveningside, *** space weather prediction and nowcasting,sophisticated models of the polar currents are needed,but concise and convenient models are also useful to predict or nowcast the principal characteristics of the current systems,such as intensity and *** this paper,we propose a "key points model" for outlining the basic features of the polar region current system for different disturbance *** "key points model"(or KP model) includes six key points of the current system:the centers of two DP2 cells,the maximum densities of the eastward and westward electrojets,and the maximum densities of the northward and southward *** of six key points is described by three parameters: intensity,local time,and *** AE-dependences of the 18 parameters are deduced from the equivalent current systems for every 5 min during a 2-d period(18-19 March 1978).The KP model reveals systematic variations of the current *** AE increases,the currents and the current densities are simultaneously enhanced linearly, and most of the key points concentrate towards *** addition,when AE increases,the key points K2 and K4 for the evening current cell move equatorward, while the key points K1 and K3 for morning cell move poleward.

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Geochronological and geochemical constraints on Aolunhua porphyry Mo-Cu deposit,northeast china,and its tectonic significance

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Geochronological and geochemical constraints on Aolunhua por...

中国科学院地质与地球物理研究所第11届（2011年度）学术年会

作者： Huaying wu~(ab*),Lianchang Zhang~a,Bo Wan~(bc),Zhiguang Chen~(a,b),Xiaojing Zhang~a,b),Peng Xiang~(a,b) ~aKey Laboratory of Mineral Resources,Institute of geology and geophysics,chinese academy of sciences,P.O.Box 9825,beijing 10002.,People’s Republic of china ~bGraduate University of chinese academy of sciences,beijing 100049,People’s Republic of china ~cState Key Laboratory of Lithosphere Evolution,Institute of geology and geophysics,chinese academy of sciences,P.O.Box 9825,beijing 10002.,People’s Republic of china

The Aolunhua porphyry Mo-Cu deposit is located in the northern margin of the North china Craton(NCC),and belongs to the northern part of the Xilamulun metallogenic *** than 90%of the mineralization occurs within the Aolunhua monzogranite-porphyry;a small part is hosted within quartz veins that crosscut Late Permian *** syenogranite,occurring as dikes and cutting through the Aolunhua monzograniteporphyry, is radially distributed in the mining *** U-Pb ages show that the Aolunhua monzogranite-porphyry and the post-ore syenogranite have concordant Pb/U ages of 138.7±1.2 Ma and 131.4±2.8 Ma,*** on analyses of major,trace elements and Hf-isotopes,the Aolunhua porphyry is characterized by high Sr low Y with high La/Yb and Sr/Y ratios typical of adakitic granites,whereas the post-ore syenogranite has lower Sr and higher Y values,showing apparently negative Eu anomalies (δEu=0.26 to 0.31).The Hf isotopic composition of the Aolunhua porphyry[ε(t)=+3.6to+9.2]and the post-ore syenogranite[ε(t)=+3.6 to+8.7]indicates that both juvenile crustal sources and depleted mantle contributed to their *** regional geological setting together with the discrepancy of geochemistry between the Aolunhua porphyry and the post-ore syenogranite probably indicates that they formed in different tectonic *** Aolunhua porphyry is derived from partial melting of the thickened crust due to underplating of the basaltic magma under the transformation tectonic regime,while the post-ore syenogranite comes from the crustal root melting during the lithospheric delamination stage under the lithosphere thinning regime of northeast china.

关键词： Zircon U-Pb dating Porphyry Mo-Cu deposit Aolunhua Xilamulun metallogenic belt Northeast china

Triassic integrative stratigraphy,biotas,and paleogeographical evolution of the Qinghai-Tibetan Plateau and its surrounding areas

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Science china Earth sciences 2024年第4期67卷 1152-1194页

作者： Guichun wu Zhansheng JI Gary GLASH Qinggao ZENG Jianxin YAO Key Laboratory of Stratigraphy and Palaeontology Ministry of Natural ResourcesInstitute of GeologyChinese Academy of Geological SciencesBeijing 100037China SinoProbe Laboratory Chinese Academy of Geological SciencesBeijing 100094China Department of geology and Environmental sciences State University of New York-FredoniaFredoniaNY 14063USA Xizang Autonomous Region Geological and Mineral Exploration and Development Burea Lhasa 850010China

Rocks of the Qinghai-Tibetan Plateau(QTP)host abundant Triassic *** far,the well established marine fossil sequences based on ammonoids,conodonts,bivalves,brachiopods,radiolarians,and terrestrial spora-pollen sequence have become standard for biostratigraphic correlation of the *** much of Triassic time,the QTP occupied a marine setting as suggested by the dominance of marine *** main sedimentary types represented in the Triassic successions include littoral to shallow marine clastic rocks,shallow marine carbonate platform carbonates,bathyal to abyssal slope carbonates intercalated with clastic and siliceous deposits,coal-bearing clastic strata contained within paralic facies deposits,and littoral and terrestrial volcaniclastic *** deposits are organized into four stages in ascending order:(1)Early Triassic deposits that record marine transgression,including extensive shallow marine carbonate platform strata.(2)Middle Triassic Ladinian to Late Triassic Carnian deposits,including thin-bedded limestone,fine clastics,and siliceous rocks,that accumulated at greater depths than underlying Early Triassic strata and reflect the peak of the *** activity appears to have occurred in some areas during this stage.(3)Late Triassic Norian deposits that record the onset of marine regression as suggested by the widespread occurrence of platform *** is noteworthy that stage 3 deposits of the Qin-Qi-Kun area in the northernmost region of the QPT is dominated by terrestrial strata and displays evidence of local erosion.(4)Late Triassic Rhaetian littoral and shallow marine clastic and coal-bearing deposits that preserve the record of continued marine regression *** Indus-Yarlungzangbo Suture Zone(IYSZ)appears to have been the rifting axis during Triassic time as suggested by sedimentary facies trends that reflect deepening to south and ***,the Himalaya Block to the south of the IYSZ was part of the passive margin

关键词： Qinghai-Tibetan Plateau Triassic Biostratigraphy Lithostratigraphy Palaeobiogeography Sedimentary palaeogeography

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In situ U-Pb dating of xenotime by laser ablation(LA)-ICP-MS

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In situ U-Pb dating of xenotime by laser ablation(LA)-ICP-MS

中国科学院地质与地球物理研究所第11届（2011年度）学术年会

作者： LIU ZhiChao~(1,2),wu FuYuan~(1*),GUO ChunLi~3,ZHAO ZiFu~4,YANG JinHui~1 & SUN JinFeng~(1,2) 1 State Key Laboratory of Litho spheric Evolution,Institute of geology and geophysics,chinese academy of sciences,beijing 10002.,china 2 Graduate University of chinese academy of sciences,beijing 100049,china 3 Institute of Mineral Deposits,chinese academy of Geological sciences,beijing 100037,china 4 School of Earth and Space sciences,University of Science and Technology of china,Hefei 230026,china

Xenotime is an ideal mineral for U-Th-Pb isotopic dating because of its relatively high U and Th contents,but typically low concentration of common *** characteristics,and the fact that it is widespread throughout various types of rocks,suggest that the U-Th-Pb dating of xenotime has broad *** of U-Pb dating on xenotime by ion microprobe(such as SHPJMP) have increased in recent years,whereas studies by laser ablation(LA)-ICP-MS are still *** this study,we developed a technique for U-Pb dating of xenotime using the 193 nm ArF laser-ablation system and Agilent 7500a *** evaluate the reliability of our method,a xenotime standard,BS-1,was analyzed and calibrated against another xenotime standard,*** weighted mean Pb/U ages of 510.1±5.2 Ma(2a,n = 21),509.8±4.3 Ma(2 a,n = 21) and 510.0±4.6 Ma(2a,n = 21) were obtained using beam diameters of 16,24 and 32μm,*** ages are identical to those determined by ID-TTMS method(weighted mean Pb/U age of 508.8±1.4 Ma),which supports the reliability of our LA-ICP-MS *** also analyzed xenotimes in leucogranites from South Tibet and granites from Xihuashan in southern china,and obtained accurate and precise ***,we observed systematic differences in Pb/U fractionation among xenotime,monazite and *** matrix-effect resulted in either under-correction or over-correction of fractionation,and thus led to inaccurate ***,a matrix -matched material is required for U-Pb dating of xenotime by LA-ICP-MS.

关键词： xenotime laser ablation(LA)-ICP-MS U-Pb dating