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Monitoring the Cultivated Slope Land in the Three Gorges Reservoir Area Based on Remote Sensing and GIS

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Wuhan University Journal of Natural Sciences 2006年第4期11卷 915-921页

作者： ZHOU Jieming1, ZHOU Qigang 2. 3.,HUANG Zhiqin 2. 3. 4.1. The {4. of Geography and {3. Science, Sichuan Normal University, Chengdu 610066, Sichuan, {2. 2. Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 61004., Sichuan, {2. 3. Graduate University of the Chinese Academy of Sciences, Beijing 10004., {2. 4. Information Center of Land and {3. Department of Sichuan Province, Chengdu 61004., Sichuan, {2. The faculty of Geography resources Science Sichuan Normal University 610066 Chengdu Sichuan China Institute of Mountain Hazards Environment Chinese Academy of Sciences 610041 Chengdu Sichuan China Graduate University of the Chinese Academy of Sciences 100049 Beijing China Information Center of Land resources Department of Sichuan Province 610041 Chengdu Sichuan China

By means of combining auto-extraction with manual interpretation, the current distribution information about cultivated land is obtained. The distribution information of 1992.is extracted from the dynamic polygons of 2.02. The monitoring mini-system of the cultivated slope land is established. In the system, detailed surveys, focused on the {3. of cultivated slope land, are carried out. The results indicate that the area of the cultivated slope land is very large. Meanwhile, there are lots of cultivated steep slopes with gradient above 3.°. The areas of steep land cultivated had been slowly reduced from 1992.to 2.02. At the same time, the pressures of returning farm land to forestry are great in all counties. The conflicts between population growth, insufficient grain supply and stagnant economic development sharpen increasingly. It is inevitable to improve the agricultural structure.

关键词： slope land cultivated remote sensing geography information system (GIS) the pressure of returning farm land to forestry Three Gorges Reservoir Area

Zhang-Xuan thermal uplift and its genesis

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Progress in Natural Science:Materials International 2005年第8期15卷 725-732页

作者： SHAO Ji'an1*, NIU Shuyin2. ZHANG Lüqiao3.and LI Hongyang2.1. School of earth and Space Sciences, Peking University, Beijing 100871, {3. 2. Shijiazhuang University of Economics, Shijiazhuang 05003., {3. 3. Geological Bureau of Inner Mongolia, Huhhot 01002., {3.) School of earth and Space Sciences Peking University Beijing 100871 China. Shijiazhuang University of Economics Shijiazhuang 050031 China. Geological Bureau of Inner Mongolia Huhhot 010020 China

Based on the researches of the Mesozoic thermal evolution history, the deformed structures, and fission track analysis of the Zhangjiakou-Xuanhua area, we obtained the following knowledge: the area experienced in 14. Ma an underplating which is marked by emplacement of mantle derived magma; during 13.—110 Ma a series of eruptions and intrusions happened, and during 80—10 Ma a rising process occurred which is synchronous with the adjacent Taihang and Yanshan Mountains and was accompanied by a series of structures down slipping from the just formed Zhang-Xuan uplift toward its periphery. Combining the Zhang-Xuan thermal lift with the large detachment structure in Baoding depression of the North china Basin in the Late Mesozoic confirms that an even larger extensional tectonic background existed in North china during this period.

关键词： Zhang-Xuan area underplating thermal uplift fission track extensional structure.

Sorption of Eu^(3.) onto nano-size silica-water interfaces

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Science china earth Sciences 2005年第11期48卷 1942-1948页

作者： HU Ping1,2. YIN Xiulan3., ZHAO Linghu1 & LI Dien4.1. Department of earth Sciences, china University of {2., Wuhan 4.1}074. china 2. Northeastern Illinois University, Chicago, IL 6062., USA 3. china Institute of Geo-Environmental Monitoring, Beijing 100081, china 4. Division of Chemistry, Los Alamos National Laboratory, Los Alamos, NM 8754., USA 1. Department of earth Sciences China University of Geosciences 430074 Wuhan China 2. Northeastern Illinois University 60625 Chicago IL USA 3. china Institute of Geo-Environmental Monitoring 100081 Beijing China 4. Division of Chemistry Los Alamos National Laboratory 87544 Los Alamos NM USA

The sorption of Eu species onto nano-size silica-water interfaces is investigated at pH range of 1―8.5 and the initial Eu concentrations (CEu) of 2.× 10?5, 2.× 10?4.and 2.× 10?3.M using fluorescence spectroscopy. The sorption rate of Eu is initially low, but significantly in-creases at pH > 4. For the initial CEu of 2.× 10?5, 2.× 10?4.and 2.× 10?3.M, the dissolved Eu spe-cies are completely sorbed onto silica-water interfaces at pH = 4.75, ~5.8 and 6.6, respectively, with the respective sorption densities of ~1.58 × 10?8, 1.58 × 10?7 and 1.58 × 10?6 mol/m2. The sorbed Eu species at pH 3., which is sorbed onto silica-water interfaces as an outer-sphere complex at pH 2. to ~6 at pH = 6. At pH = 6 – 8, Eu(OH)2., Eu(CO3.+ and Eu(CO3.2. form in the solutions, and Eu(CO3.+ is dominant at pH = ~7.5. These ions may be sorbed onto silica-water interfaces as inner-sphere bidentate complexes or multi-nuclear pre-cipitates.

关键词： surface sorption, Eu3. species, nano-size silica, fluorescence spectroscopy, immobilization of toxic metals

Southeastern extension of the Red River fault zone (RRFZ) and its tectonic evolution significance in western South china Sea

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Science china earth Sciences 2006年第8期49卷 839-850页

作者： LIU Baoming1,2.3. XIA Bin1, LI Xuxuan1,3. ZHANG Minqiang1,3. NIU Binhua2. ZHONG Lifeng1, JIN Qinghuan1,4.& JI Shaocheng1,5 1. Key Laboratory of Marginal Sea Geology and resources, Chinese Academy of Sciences,Guangzhou 51064., {3. 2. {3. University of geosciences (Beijing), Beijing 100083. {3. 3. Research Center of Science & Technology Department, CNOOC, Beijing 10002., {3. 4. Guangzhou Marine Geological Survey, Ministry of Land & resources, Guangzhou 510075, {3. 5. Ecole Polytechnique Montreal, H3.3.7, Canada 1. Key Laboratory of Marginal Sea Geology and resources Chinese Academy of Sciences Guangzhou 510640 China 2. china University of geosciences (Beijing) Beijing 100083 China 3. Research Center of Science & Technology Department CNOOC Beijing 100027 China 4. Guangzhou Marine Geological Survey Ministry of Land & Resources Guangzhou 510075 China 5. Ecole Polytechnique Montreal H3C3A7 Canada

Recent geophysical surveys and basin modeling suggest that the No.1 fault in the Ying- gehai basin (YGHB) is the seaward elongation of the Red River fault zone (RRFZ) in the South china Sea (SCS). The RRFZ, which separates the South china and Indochina block, extends first along the Yuedong fault, offshore of Vietnam, and then continues southward and breaks off into two branches: the Lupar fault and the Tinjia fault. The southern extension of the Lupar fault dies out beneath the NW Borneo while the Tinjia fault extends southeast and reaches the Brunei-Sabah area. According to the gravity and geomagnetic data, and the tectonic evolution of the basins, there are different evolution histories between the Wan’an basin (WAB) and the basins in the Nansha block. The Tinjia fault may be the boundary between the Balingian block and the Nansha block. Hence, the line linking the Yue- dong fault and the Tinjia fault, which both are continental margin faults and strike-slip ones in the geological evolution histories, constitute the boundary between the Indochina and Nansha block. The Lupar fault, in contrast, is an intraplate fault within the Indochina block. The results provide new hints for reconstructing the tectonic evolution history of the RRFZ and the opening of the SCS, and also a framework for hydrocarbon prospecting in the region.

关键词： Red River fault zone, tectonic evolution, fault, extension, western South china Sea.

Dehydration melting of solid amphibolite at 2.0 GPa: Effects of time and temperature

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Science china earth Sciences 2005年第8期48卷 1120-1133页

作者： ZHOU Wenge1, XIE Hongsen1, LIU Yonggang1, ZHENG Xiaogang1, ZHAO Zhidan2.& ZHOU Hui3.1. Laboratory of Material in the earth’s Interior, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002. {3. 2. Department of Geology, {3. University of geosciences, Beijing 100083. {3. 3. Department of Geology, Peking University, Beijing 100871, {3. 1. Laboratory of Material in the earth’s Interior Institute of Geochemistry Chinese Academy of Sciences 550002 Guiyang China 2. Department of Geology China University of Geosciences 100083 Beijing China 3. Department of Geology Peking University 100871 Beijing China

Two sets of dehydration-melting with a natural solid amphibolite, collected from North Himalayan structure zone, Tibet, have been carried out in multi-anvil apparatus at 2.0 GPa and 800―1000℃, for 12.2.0 h. One is keeping the pressure at 2.0 GPa and the annealing time of 12.h, changing the temperature (800―1000℃). The other is keeping the pressure at 2.0 GPa and temperature at 850℃, varying the annealing time (12.2.0 h). The products are inspected with microscope and electron probe. The results indicate that at 2.0 GPa, annealing time of 12.h, garnets, melts and clinopyroxenes occur in amphibolite gradually with increasing temperature and the chemical compositions of melt vary from tonalite to granodiorite, and then to tonalite. However, at 2.0 GPa and 850℃, with the annealing time increasing, the garnets, melts and cli-nopyroxenes also occur in amphibolite gradually and the chemical compositions of melt vary from tonalite to granodiorite. In both cases, melts interconnect with each other when the contents of melt are over the 5 vol.%. the viscosities of the melt produced in amphibolite at temperature higher than 850℃ are on a level with 104.Pa·s. The interconnected melt with such a viscosity may segregate from the source rock and form the magma over reasonable geological time. Therefore, it is believed that at the lower part of the overthickened crust, the tonlitic and grano-dioritic magma may be generated through the dehydration melting of amphibolite.

关键词： solid amphibolite, high pressure, high temperature, time, partial melting.

Sm-Nd and zircon SHRIMP U-Pb dating of Huilanshan mafic granulite in the Dabie Mountains and its zircon trace element geochemistry

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Science china earth Sciences 2005年第12期48卷 2081-2091页

作者： HOU Zhenhui1, LI Shuguang1, CHEN Nengsong2. LI Qiuli1 & LIU Xiaoming3.1. School of earth and Space Sciences, University of Science and Technology of china, Hefei 2.002., china 2. The Key Laboratory of Continental Dynamics of the Ministry of Education, Northwest University, Xi’an 710069, china 3. faculty of earth Sciences, china University of geosciences, Wuhan 4.1}074. china 1. School of earth and Space Sciences University of Science and Technology of China 230026 Hefei China 2. The Key Laboratory of Continental Dynamics of the Ministry of Education Northwest University 710069 Xi’an China 3. faculty of earth Sciences China University of Geosciences 430074 Wuhan China

The mafic granulites from Huilanshan are outcropped on the center of the Luotian dome in the northern Dabie Mountains. The Sm-Nd isochron defined by granulite-facies meta-morphic minerals (garnet + clinopyroxene + hypersthene) yields an age of 13. ± 18 Ma indicating the early Cretaceous granulite-facies metamorphism. The cathodoluminescence (CL) images of zircons from the granulite show clearly core-mantle-rim structures. The zircon cores are charac-terized by typical oscillatory zoning and highly HREE enriched patterns, which suggests their magma origin. Some zircon cores among them with little Pb loss give SHRIMP U-Pb ages rang-ing from 753.to 780 Ma, which suggests that the protolith of Huilanshan granulite is Neopro-terozoic mafic rocks. The zircon mantles usually cut across the oscillatory zone of the zircon cores have 3.10 times lower REE, Th, U, Y, Nb and Ta contents than the igneous zircon cores but have high common Pb contents. These characteristics suggest that they were formed by hydrothermal alteration of the igneous zircons. The part of zircon mantles with little Pb loss give a similar SHRIMP U-Pb age (716―780 Ma) to the igneous zircon cores, which implies that the hydrothermal events occurred closely to the magmatic emplacement. In view of the strong early Cretaceous magmatism in the Luotian dome, consequently, the Huilanshan mafic granulite was formed by heating of the Neoproterozoic mafic rocks in mid-low crust, which caused the granu-lite-facies metamorphism underneath the Dabie Mountains. The similarity between the granulite metamorphic age (13. ± 18 Ma) defined by Sm-Nd isochron and K-Ar age of 1{4.―1{4. Ma given by amphible from the gneiss in Luotian dome suggests a rapid uplifting of the Luotian dome, which may result in further exhumation of the ultrahigh pressure metamorphic rocks in the Dabie Mountains.

关键词： Dabie orogen, granulite, zircon U-Pb ages, Sm-Nd age.

Geophysical survey on the tectonic and sediment distribution of Qinghai Lake basin

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Science china earth Sciences 2006年第8期49卷 851-861页

作者： AN Zhisheng1, WANG Ping2. SHEN Ji3. ZHANG Yixiang2. ZHANG Peizhen4. WANG Sumin3. LI Xiaoqiang1, SUN Qianli1, SONG Yougui1, AI Li1, ZHANG Yechun2. JIANG Shaoren2. LIU Xingqi3.& WANG Yong3.. Institute of earth Environment, Chinese Academy of Sciences (CAS), Xi’an 710075, china 2. South china Sea Institute of Oceanology, CAS, Guangzhou 5103.1, china 3. Nanjing Institute of Geography and Limnology, CAS, Nanjing 2.0008, china 4. Institute of Geology, china earthquake Administration, Beijing 10002., china 1. Institute of earth Environment Chinese Academy of Sciences (CAS) Xi’an 710075 China 2. South china Sea Institute of Oceanology CAS Guangzhou 510301 China 3. Nanjing Institute of Geography and Limnology CAS Nanjing 210008 China 4. Institute of Geology China Earthquake Administration Beijing 100029 China

The intensive geophysical survey of Qinghai Lake reveals the buried depth of lake sediments and their distribution features. The result indicates that there are three important inter- phases of Qinghai Lake sediments: T1 is the rife interphase of the lake, above which sediments are spread all over the lake basin with roughly the same thickness; T5 is the interphase from which the neotectonic sedimentary cycle begins, and its above sedimentary environment is relatively stable; Tg is the base of the lake basin. Five west-northwest (WNW) fault belts defined the tectonic structure of Qinghai Lake basin: the central hunch around Haixin Shan with two subbasins both in its north and south. The thickness of the lake sediments varies at different places, the thickest sediments are found within the two subbasins. According to the depth that the Sparker System can reach, sediment in the northern subbasin is deeper than 560 m, while sediment in the southern subbasin is deeper than 700 m. The correlation between the seismic sequence stratigraph and the lithology of onshore core shows that Qinghai Lake sediments consist of muddy silt, clay silt, silty clay, gravel silty clay, etc.

关键词： sediment, geophysical survey, Qinghai Lake.

Magnetic mineralogy of the Hongqiling Cu-Ni sulphide deposit: Implications for ore genesis

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Progress in Natural Science:Materials International 2007年第10期17卷 1192-1198页

作者： Xi Aihua1,2. Ge Yuhui1, Cai Yuanfeng2.and Zhang Xuefeng3.1. faculty of {3. & Environment, Southwest Petroleum University, Chengdu 610500, {2. 2. State Key Laboratory for Endogenic Metal Deposit Research, Nanjing University, Nanjing 2.0093. {2. 3. Department of Natural {3. & Technology Information, {2. University of Petroleum, Beijing 102.4., {2.) faculty of resources & Environment Southwest Petroleum University Chengdu 610500 China State Key Laboratory for Endogenic Metal Deposit Research Nanjing University Nanjing 210093 China Department of Natural resources & Technology Information China University of Petroleum Beijing 102249 China

Pyrrhotite is one of the common ore minerals in Cu-Ni sulphide deposits, but only monoclinic pyrrhotite is ferromagnetic at room temperature. X-ray and EPA analyses reveal that most pyrrhotite forming sideronitic texture in the Hongqiling Cu-Ni sulphide deposit is monoclinic, but that in the massive ore is a mixture of monoclinic and hexagonal pyrrhotites. Differential thermal and magnetic- thermogravimetric analyses of massive ore indicate a magnetic transition and heat absorption at 3.0}℃, suggesting that this temperature is the thermomagnetic and phase transition point of pyrrhotite. For massive pyrrhotite ores heated at 4.0oC for 3. h and then quenched by cool water, the monoclinic pyrrhotite (mpo) transforms completely into the hexagonal pyrrhotite (hpo). However, all the pyrrhotites resulting from slow cooling of the sample in air are mpo. These results indicate that transformation between hpo and mpo depends upon the cooling rate. Therefore, massive ores in this deposit might have been formed via rapid cooling of ore melts. On the other hand, it is significant to study the effect of the ratio of the magnetite in total ores on the genesis of magmatic Cu-Ni suphide deposits.

关键词： pyrrhotite magnetite genesis of Cu-Ni sulphide deposit Hongqiling.

Re-Os age for molybdenite from the Gangdese porphyry copper belt on Tibetan plateau: Implication for geody- namic setting and duration of the Cu mineralization

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Science china earth Sciences 2004年第3期47卷 221-231页

作者： HOU Zengqian1, QU Xiaoming1, WANG Shuxian2. DU Andao2. GAO Yongfeng3.& HUANG Wei4.1. Institute of Mineral resources, Chinese Academy of Geological Sciences, Beijing 10003., {3. 2. National Center of Geoanalysis, Chinese Academy of Geological Sciences, Beijing 10003., {3. 3. Shijiazhuang College of Economy, Shijiazhuang 056000, {3. 4. Xizang Bureau of Geology and Mineral resources, Lhasa 850000, {3. Chinese Acad Geol Sci Inst Mineral Resources Beijing 100037 Peoples R China Chinese Acad Geol Sci Natl Ctr Geoanal Beijing 100037 Peoples R China Shijiazhuang Coll Econ Shijiazhuang 056000 Peoples R China Xizang Bur Geol & Mineral resources Lhasa 850000 Peoples R China

The Gangdese porphyry copper belt consists of one large and five middle-small deposits in addition to dozens of ore-bearing porphyry bodies. The belt trends 3.0 km long along the EW-striking Gangdese batholith, and locally occurs as a string of beads extending about 50 km within the SN-trending rifting zones (grabens) on the Tibetan plateau. Monzonitic granite- porphyry and quartz monzonitic porphyry, as dominant host rocks, are shoshonitic and potassic calc-alkaline. Available dating data indicate that the ages of the shallow-level emplacement for these porphyries vary from 10 Ma to 18 Ma, which are identical to that of associated potassic calc-alkaline volcanic rocks (10—15 Ma) and mafic dykes (13.18 Ma). The timing and duration of Cu mineralization events are constrained by Re-Os ages for molybdenites from three porphyry copper deposits in the Gangdese porphyry copper belt. Five molybdenite samples from the Nanmu deposit yielded an 187Re-187Os isochron with a highly pre-cise age of (14.76?.2.) Ma; six molybdenites from the Chongjiang deposit gave an isochron age of (14.04..16) Ma. Re-Os model ages for two molybdenite samples from Lakang抏 deposit vary from 13.5 Ma to 13.6 Ma, which are basically identical to isochron ages mentioned above. All the thirteen samples from these three deposits yielded a linear array in the isochron diagram with a higher correlation coefficient of 0.99719 and an isochron age of (14.3.?.2.) Ma (1s error), suggesting an coeval event of the Cu mineralization and a shared source of ore materials for the Gangdese porphyry copper belt. Compared with the longer-lived felsic magmatic-hydrothermal system, the Cu mineralization is a relatively short event with duration of about 0.5 Ma, and usu-ally occurs in the later-stage of the complicate magmatic system. The emplacement age of the Gangdese porphyries indicates that they intruded after the rapid rising of the Gangdese Mountains at 2.—2. Ma, and formed in a post-collision crustal ex-tension env

关键词： porphyry copper deposit, Re-Os age, Gangdese, Tibetan plateau.