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Magnetostratigraphy of Late Cenozoic fossil mammals in the northeastern margin of the Tibetan Plateau

Science Bulletin 2003年第2期48卷 188-193页

作者： SONG Chunhui1,2.FANG xiaomin 1,2.GAO Junping1, NIE Junsheng1,YAN Maodu1,3.XU xianhai1 & SUN Dong1 1. MOE National Laboratory of Western China抯 environmental Systems & College of Resource and environment,Lanzhou University,Lanzhou 73.000,China 2. State Key Laboratory of Loess and Quaternary Geology ,{2. of {3. environment,Chinese academy of sciences,xi抋n {13., China 3. Department of Geological sciences,University of Michigan,AnnArbor,MI 48109,USA Univ Arizona Steward Observ Tucson AZ 85721 USA MOE National Laboratory of Western China\'s environmental Systems & College of Resource and environment Lanzhou University Lanzhou 730000 China

A number of fossil mammals have been found in the very thick Cenozoic stratigraphy of the Guide Basin in the northeastern margin of the Tibetan *** of these are of great significance in mammal evolution and stratigraphic correla-tion on and around the Tibetan Plateau and North ***,the chronology of these mamals is poorly *** of the mammals will not only place precise age constraints on the mammals,but also provide much inlormation on the related stratigraphy that records the uplift process of the Tibetan *** paleomagnetism of the upper part of the Cenozoic stratigraphy at He'erjia and Lajigai north of Guide County has revealed magnetic chrons that can be correlated to Ganss and 3.n *** the section spanning about 3.16.5 Ma and the *** and third layers of fossil mammals at about 5.2.,5.1 and 4.4 Ma,*** of the significant genus Gazella kueitensis and the Chinese elephant Anancus sinensis are firstly constrained at about 5.2. MaBP and 4.4 Ma,*** mammalian evolution and the associated increase in coarse sediments and sedimentation rate may suggest that the northeastern Tibetan Plateau was uplifted rapidly at that time,and the eastern Tibetan Plateau with its neighboring regions was not high enough to stop mammal exchange between the northern and southern sides of the Tibetan Piateau.

关键词： Tibetan Plateau Guide Basin Late Cenozoic stratigra-phy fossil mammals paleomagnetism.

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Characterization of MASDs of surface soils in north China and its influence on estimating dust emission

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Chinese Science Bulletin 2004年第20期49卷 2169-2176页

作者： MEI Fanmin1,2. ZHANG xiaoye1, LU Huayu1, SHEN Zhenxing1 & WANG Yaqiang1 1. State Key Laboratory of Loess and Quaternary Geology, {3. of earth {2., Chinese {3. of sciences, xian 710075, China 2. xian University of Engineering Science and Technology, xian 710048, China State Key Laboratory of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences Xi''an 710075 China xi''an University of Engineering Science and Technology Xi''an 710048 China

The micro-aggregated size distribution (MASD) of surface soil is an important parameter for modelling dust emission. However, there is no dataset of MASDs of all sur-face soil types in north China. The MASDs are here pre-sented, measured by dry sieving, for typical surface soil sam-ples, including sandy soil, gravelly sand soil, gravelly loam soil, loam soil and silt loam soil, collected from sandy deserts, Gobi deserts, oases, farmlands in steppe regions and steppe areas in north China. The MASDs of various surface soil types exhibit a combination of several log-normal distribu-tions of five separated sizes with mean mass median diame-ters (MMDs) of 90, 2.0, 3.0, 600 and 980 mm, respectively, and mean standard deviations (SDs) of 1.2., 1.40, 1.2., 1.3. and 1.2. respectively. The log-normal distributions corre-spond to very fine sand, fine sand, medium sand, coarse sand and very coarse sand population. On the basis of characteri-zation of the retrieved MASDs of various surface soil types in north China, dust emission fluxes are modelled by a dust production model (DPM model). It is shown that dust emis-sion has been significantly influenced by MASDs. Fine sand and very fine sand are always associated with the highest dust emission fluxes. Emission fluxes of the medium sand, gravelly sand soil, gravelly loam soil and loam soil are lower than those of very fine sand and fine sand, but larger than those of the coarse sand. The differences in dust emission fluxes vary among the different soil types from 101 to 103.mg·m-2.s-1. Dust emission fluxes from sandy deserts and farmlands covered with sand sheets in north China rang from 101 to 104 mg·m-2.s-1 while those from Gobi deserts, farmlands and steppes with gravelly desertification range from 101 to 102.mg·m-2. s-1. The modelled results indicate that deserts and farmlands with sand are the major dust sources in north China.

关键词：华北地区 MASDs 微块状粒度分布地面土壤粉尘排放壤土大气污染气溶胶

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Variations of near-surface atmospheric CO_(2.and H_(2.O concentrations during summer on Muztagata

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Science China earth sciences 2006年第1期49卷 18-26页

作者： XU Baiqing1,2. YAO Tandong1,2. LU Anxin2. GUO Xuejun, LIU xianqin2.& LI Zhen2.1. Laboratory of environment and Process on Tibetan Plateau, institute of Tibetan Plateau Research, Chinese {2. of {3., Beijing 100085, China 2. Key Laboratory of Cryosphere and environment, Jointly Established by Cold and Arid Regions environmental and Engi-neering Research institute and institute of Tibetan Plateau Research, Chinese {2. of {3. and Chinese {2. of Meteorological {3., China Meteorological Administration, Lanzhou 73.000, China 1. Laboratory of environment and Process on Tibetan Plateau Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing 100085 China 2. Key Laboratory of Cryosphere and environment Jointly Established by Cold and Arid Regions Environmental and Engineering Research Institute and Institute of Tibetan Plateau Research Chinese Academy of Sciences and Chinese Academy of Meteorological Sciences China Meteorological Administration Lanzhou 730000 China

Expeditions during the summers of 2.02.and 2.03.implemented continuous monitoring of near-surface (2.m height) atmospheric CO2.and H2. concentrations at the 4500 m elevation on Muztagata. The resultant data sets reveal a slight decrease of CO2.concentrations (of about 5 μmol·mol?1) and changes in the diurnal variations from the end of June to the middle August. The daily maximum CO2.concentrations occur between 02.3.―05:3. AM (local time) and the minimum levels occur between 12.00―15:3. PM. The atmospheric CO2.concentrations in the summer of 2.02.were around 5 μmol·mol?1 lower than those during the same period of 2.03. whereas the diurnal amplitude was higher. In contrast, we found that the daily mean atmospheric H2. content in 2.03.was much lower than that in 2.02.and there exists a striking negative correlation between CO2.and H2. con-centrations. We therefore suggest that the near-surface atmospheric CO2.concentration is affected not only by photosynthesis and respiration, but also by the air H2. content in the glaciated region around Muztagata.

关键词： atmospheric CO2 and H2. concentration, continuous monitoring, glaciation region, Muztagata.

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A three-dimensional variational ocean data assimilation system:Scheme and preliminary results

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Science China earth sciences 2006年第11期49卷 1212-1222页

作者： ZHU Jiang1,2. ZHOU Guangqing1, YAN Changxiang1, FU Weiwei1 & YOU xiaobao1,3.1. International Center for Climate and {3. sciences, {2. of Atmospheric Physics, Chinese {3. of sciences, Beijing 10002., China 2. Jiangsu Key Laboratory of Meteorological Disaster, Nanjing University of Information Science and Technology, Nanjing 2.0044, China 3. Beijing {2. of Applied Meteorology, Beijing 10002., China 1. International Center for Climate and environment sciences Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China 2. Jiangsu Key Laboratory of Meteorological Disaster Nanjing University of Information Science and Technology Nanjing 210044 China 3. Beijing institute of Applied Meteorology Beijing 100029 China

A new 3.VAR-based Ocean Variational Analysis System (OVALS) is developed. OVALS is capable of assimilating in situ sea water temperature and salinity observations and satellite altimetry data. As a component of OVALS, a new variational scheme is proposed to assimilate the sea surface height data. This scheme considers both the vertical correlation of background errors and the nonlinear temperature-salinity relationship which is derived from the generalization of the linear balance constraints to the nonlinear in the 3.VAR. By this scheme, the model temperature and salinity fields are directly adjusted from the altimetry data. Additionally, OVALS can assimilate the temperature and salinity profiles from the ARGO floats which have been implemented in recent years and some temperature and salinity data such as from expendable bathythermograph, moored ocean buoys, etc. A 2.-year assimilation experiment is carried out by using OVALS and the Tropical Pacific circulation model. The results show that the assimilation system may effectively improve the estimations of temperature and salinity by assimilating all kinds of observations. Moreover, the root mean square errors of temperature and salinity in the upper depth less than 42. m reach 0.63. and 0.3. psu.

关键词： data assimilation, 3.VAR, sea surface height, ARGO floats.

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Ecological response to the climate change on the northern slope of the Tianshan Mountains in xinjiang

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Science China earth sciences 2005年第6期48卷 765-777页

作者： CHEN xi1, LUO Geping1, xiA Jun2. ZHOU Kefa1, LOU Shaoping3.& YE Minquan4 1. xinjiang institute of Ecology and Geography, Chinese academy of {2., Urumqi 83.011, China 2. institute of Geographical and Resources {2., Chinese academy of {2., Beijing 100101, China 3. Urumqi Meteorological-satellite Land Station, Urumqi 83.011, China 4. Seismological Bureau of xinjiang Uygur Autonomous Region, Urümqi 83.011, China Correspondence should be addressed to Chen xi 1. xinjiang institute of Ecology and Geography Chinese Academy of Sciences 830011 Urumqi China 2. institute of Geographical and Resources sciences Chinese Academy of Sciences 100101 Beijing China 3. Urumqi Meteorological-satellite Land Station 830011 Urumqi China 4. Seismological Bureau of xinjiang Uygur Autonomous Region 830011 Urümqi China

The Tianshan Mountains is a high and huge mountain body lying across the central part of xinjiang, China, and is also the main area where the runoff forms in xinjiang. In this paper, a set of RS-based study methods is put forward for deriving the information about the natural change of the ecology in arid areas, and the relationship between the climate change trend and the corresponding ecological response on the northern slope of the Tianshan Mountains since recent 40 years is analyzed from the scales of the land cover ecosystems and landscapes based on the observed data of climate, hydrology, modern glaciers and lakes on the northern slopes of the Tianshan Mountains since recent 40 years and the satellite RS data since recent 10 years by using the RS and GIS technologies. The results are as follows: (1) The overall trend of climate change on the northern slope of the Tianshan Mountains since recent 40 years is that both air temperature and precipitation are increased, especially the increase amplitudes of air tempera-ture, precipitation and annual runoff volume are high since the decade of the 1990s; (2. the in-tegrated indexes of the vegetation in all the geographical divisions on the northern slope of the Tianshan Mountains are obviously increased since recent 10 years, especially in the artificial oases and the foothill belts, such a change trend is advantageous for improving the vegetation ecology; and (3. the vegetation ecology in the arid areas is extremely sensitive to the climate change, the vegetation coverage and the biomass on the northern slope of the Tianshan Moun-tains are continuously increased because of the climate change since recent 10 years, their in-crease amplitudes in the plains and during the late stage are obviously higher than that in the mountainous regions and during the early stage.

关键词： north slope of the Tianshan Mountains, climate change, hydrological change, natural change of ecology,RS and GIS, vegetation index.

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Relationships between δ ^(18)O in summer precipitation and temperature and moisture trajectories at Muztagata, western China

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Science China earth sciences 2006年第1期49卷 27-35页

作者： YU Wusheng1,2. YAO Tandong1,2. TIAN Lide1,2. LI Zhen2. SUN Weizhen2.& WANG Yu2.1. Laboratory of environment and Process on Tibetan Plateau, institute of Tibetan Plateau Research, Chinese {2. of {3., Beijing 100085, China 2. Key Laboratory of Cryosphere and environment, Jointly Established by Cold and Arid Regions environmental and Engi-neering Research institute and institute of Tibetan Plateau Research, Chinese {2. of {3. and Chinese {2. of Meteorological {3., China Meteorological Administration, CAS, Lanzhou 73.000, China 1. Laboratory of environment and Process on Tibetan Plateau Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing 100085 China 2. Key Laboratory of Cryosphere and environment Jointly Established by Cold and Arid Regions Environmental and Engineering Research Institute and Institute of Tibetan Plateau Research Chinese Academy of Sciences and Chinese Academy of Meteorological Sciences China Meteorological Administration Lanzhou 730000 China

Based on summer observations of stable isotope of precipitation at Muztagata, western China, during 2.02.2.03. this paper presents the relationship between δ 18O in precipitation and air temperature, and discusses the effect of moisture transport on δ 18O in precipitation. Results show that air temperature correlates positively with δ 18O in precipitation, and the temperature effect controls the δ 18O of precipitation in this area. The Muztagata region exhibits high δ 18O values in summer precipi-tation, similar to those shown at stations in adjacent regions. According to the results of our model set up to trace the moisture trajectories, the westerlies and local moisture circulation contribute to varia-tions of oxygen isotopes in precipitation. In addition, the impacts of the moisture transport distance, the moisture transport level, and the incursion of the polar air mass also influence the variations of δ 18O in precipitation. The moisture origins and transport mechanisms also contribute to the variation of δ 18O in precipitation at Muztagata.

关键词： Muztagata, δ18O, precipitation, temperature, moisture transport.

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Grain size record of microparticles in the Muztagata ice core

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Science China earth sciences 2006年第1期49卷 10-17页

作者： WU Guangjian1,2. YAO Tandong1,2. XU Baiqin1,2. LI Zheng2. TIAN Lide1,2. DUAN Keqin2.& WEN Linke2.1. Laboratory of environment and Process on Tibetan Plateau, institute of Tibetan Plateau Research, Chinese {2. of {3., Beijing 100085, China 2. Key Laboratory of Cryosphere and environment, Jointly Established by Cold and Arid Regions environmental and Engi-neering Research institute and institute of Tibetan Plateau Research, Chinese {2. of {3. and Chinese {2. of Meteorological {3., China Meteorological Administration, Lanzhou 73.000, China 1. Laboratory of environment and Process on Tibetan Plateau Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing 100085 China 2. Key Laboratory of Cryosphere and environment Jointly Established by Cold and Arid Regions Environmental and Engineering Research Institute and Institute of Tibetan Plateau Research Chinese Academy of Sciences and Chinese Academy of Meteorological Sciences China Meteorological Administration Lanzhou 730000 China

The dust transport and sediment characteristics are discussed based onanalysis of mi-croparticle size and size distribution in the Muztagata ice core at 63.0 m a.s.I. Thefiner particles with diameter of 1—5 μm are the dominant fraction in number, while middle andcoarse particles mainly contribute to the total volume. The lognormal distribution characteristicscan be seen for some high concentration samples, showing that model size and standard variation aregreater than that in the Greenland ice cores. However, size-volume distribution of some lowconcentration samples is abnormal. Those distributions reflect the dust deposit process in highmountain glaciers at mid-low latitudes and show differences from those in polar ice sheet.

关键词： Muztagata, ice core, microparticle, dust, size distribution.

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Prediction of Debris-flow Danger Area by Combining Hydrological and Inundation Simulation Methods

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Journal of Mountain Science 2011年第1期8卷 1-9页

作者： CUI Peng Key Laboratory of Mountain Hazards and earth Surface Process Chinese Academy of Sciences Chengdu 610041 China institute of Mountain Hazards and environment Chinese Academy of Sciences Chengdu 610041 China Graduate School of Chinese academy of sciences Beijing 100049 China

Debris flows have caused serious human casualties and economic losses in the regions strongly affected by the Ms8.0 Wenchuan earthquake of 2.o8. Debris flow mitigation and risk assessment is a key issue for reconstruction. The existing methods of inundation simulation are based on historical disasters and have no power of prediction. The rain- flood method can not yield detailed flow hydrograph and does not meet the need of inundation simulation. In this paper, the process of water flow was studied by using the Arc-SCS model combined with hydraulic method, and then the debris flow runoff process was calculated using the empirical formula combining the result from Arc-SCS. The peak discharge and runoff duration served as input of inundation simulation. Then, the dangerous area is predicted using kinematic wave method and Manning equation. Taking the debris flow in Huashiban gully in Beichuan County, Sichuan Province, China on 2. Sep. 2.o8 as example, the peak discharge of water flow and debris flow were calculated as 3..52.m3.s-1 and 2.5.66 m3.s-, with error of 4.15% compared to the measured values. The simulated area of debris-flow deposition was 161,500 m2. vs. the measured area of 144,097 m2. in error of 81.75%. The simulated maximum depth was 12.3.m, consistent with the real maximum depth between lO and 15 m according to the field survey. The minor error is mainly due to the flow impact on buildings and variations in cross-section configuration. The present methodology can be applied to predict debrisflow magnitude and evaluate its risk in other watersheds inthe earthquake area.

关键词： Debris flow Arc-SCS model Inundation simulation Risk analysis Wenchuan earthquake

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Land cover changes based on plant successions: Deforestation, rehabilitation and degeneration of forest in the upper Dadu River watershed

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Science China earth sciences 2005年第12期48卷 2214-2230页

作者： YAN Jianzhong1,2.3. ZHANG Yili1, BAI Wanqi1, LIU Yanhua4, BAO Weikai5, LIU Linshan1, 2.& ZHENG Du1 1. institute of Geographic {3. and Natural Resources Research, Chinese {2. of {3., Beijing 100101, China 2. Graduate School of the Chinese {2. of {3., Beijing 10003., China 3. College of Resources and environment, Southwest Agricultural University, Chongqing 400716, China 4. The Ministry of Science and Technology, P. C. China, Beijing 100862. China 5. Chengdu institute of Biology, Chinese {2. of {3., Chengdu 610041, China 1. institute of Geographic sciences and Natural Resources Research Chinese Academy of Sciences 100101 Beijing China 2. Graduate School of the Chinese academy of sciences 100039 Beijing China 3. College of Resources and environment Southwest Agricultural University 400716 Chongqing China 4. The Ministry of Science and Technology P. C. China 100862 Beijing China 5. Chengdu institute of Biology Chinese Academy of Sciences 610041 Chengdu China

To link regional land use/cover changes with environmental effects, land cover changes are required to reflect vegetation successions, whereas the land cover classification systems commonly used nowadays cannot serve this purpose. In this paper, a new land cover classification system is established in which land covers are classified by the vegetation succes-sions, taking Zamtang County, Barkam County and Jinchuan County in the upper Dadu River watershed as a study area. Using multi-temporal remote sensing images, the land cover data of 1967, 1986 and 2.00 are obtained by means of integration of unsupervised classification and visual interpretation methods. The database facilitates the study of land use/cover changes, en-vironmental effects and ecological construction. Land cover changes reflect the main ecological processes in the upper Dadu River watershed. The landscape composed mainly of grasslands, wildwoods and alpine scrubs in 1967 was changed to that of grasslands, secondary forests, al-pine scrubs, fragmentary wildwoods, artificial forests, secondary scrubs in 2.00, meanwhile, the landscape got more fragmentized. The total area of the forests decreased by 9.43.. Study results have shown the process of restoration of logged areas in forest centers. From 1967 to 2.00, only 6.86 percents of logged areas were converted to shrubs, meadows or crop-lands, and the rest were converted into artificial forests or secondary forests. So the ecological shelter functions will be restored, stage by stage. Firewood collection, charcoal production and overgrazing are the three major triggers for the extensive degradation of alpine oak forests, Sa-bina tibetica forests and meadows. The arid valley grasslands expanded too. The degradation of vegetation in the southern slopes impairs ecological shelter functions and affects livelihood of local residents, so it is essential to find effective measures for ecological restoration and recon-struction. Field investigations have found

关键词： land use/cover classification, upper Dadu River watershed, vegetation successions, GIS, RS.

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Paleomagnetic dating of the Cenjiawan Paleolithic site in the Nihewan Basin, northern China

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Science China earth sciences 2006年第3期49卷 295-303页

作者： WANG Hongqiang1,2. DENG Chenglong1, ZHU Rixiang1 & xiE Fei3.1. Paleomagnetism and Geochronology Laboratory (SKL-LE), {3. of Geology and Geophysics, Chinese academy of Sci- ences, Beijing 10002., China 2. School of the {2. {3. and Resources, China University of Geo{3., Beijing 100083. China 3. Hebei Province {3. of Cultural Relics, Shijiazhuang 050000, China 1. Paleomagnetism and Geochronology Laboratory (SKL-LE) Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China 2. School of the earth sciences and Resources China University of Geosciences Beijing 100083 China 3. Hebei Province institute of Cultural Relics Shijiazhuang 050000 China

Rock magnetic and magnetostratigraphic investigations on a lacustrine sequence in the Nihewan Basin, northern China, which bears the Cenjiawan Paleolithic site, indicate that the dominant magnetic mineral and remanence carrier contained in the sediments is magnetite. While hematite co-exists with magnetite in some portions of the Cenjiawan sequence, where characteristic remanent magnetizations are carried by both magnetite and hematite. Measurements of anisotropy of magnetic susceptibility confirm that the Cenjiawan sequence has preserved the original sedimentary features and is suitable for magnetostratigraphic study. Paleomagnetic results indicate that the Cenjiawan Paleolithic site is formed just posterior to the Punaruu normal event, which is dated at about 1.1 Ma. Combined with the paleomagnetic results of the Donggutuo, xiaochangliang and Majuangou sections, it is concluded that early humans were occupying the Nihewan Basin around 1.6, 1.3.and 1.1 Ma. This integrated result is significant to understanding the ability of migration and adaptation to the envi- ronment of early humans.

关键词： Nihewan Basin, Early Pleistocene, Cenjiawan, Paleolithic site, paleomagnetism.

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