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

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 {1., {1. of Earth Environment, Chinese {2. of sciences, Xian 71.075, China 2. Xian University of Engineering Science and Technology, Xian 71.048, 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, 390, 600 and 980 mm, respectively, and mean standard deviations (SDs) of 1.2., 1.40, 1.2., 1.35 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 1.1.to 1.3 mg·m-2.s-1. Dust emission fluxes from sandy deserts and farmlands covered with sand sheets in north China rang from 1.1.to 1.4 mg·m-2.s-1.while those from Gobi deserts, farmlands and steppes with gravelly desertification range from 1.1.to 1.2.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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Paleoenvironments indicated by the fossil mammalian assemblages from red clay-loess sequence in the Chinese Loess Plateau since 8.0 Ma B.P.

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Science China Earth sciences 2006年第5期49卷 518-530页

作者： XUE Xiangxu1,2. ZHANG Yunxiang1,2.& YUE Leping1,2.1. State Key Laboratory of Continent Dynamics (Northwest University), institute of Cenozoic {1. and Environment, De- partment of {1., Northwest University, Xi’an 710069, China 2. institute of Earth Environment, State Key Laboratory of Loess and Quaternary {1., Chinese academy of sciences, Xi’an 710075, China 1. State Key Laboratory of Continent Dynamics (Northwest University) Institute of Cenozoic Geology and Environment Department of Geology Northwest University Xi’an 710069 China 2. {1. of Earth Environment State Key Laboratory of Loess and Quaternary Geology Chinese Academy of Sciences Xi’an 710075 China

Information from eleven profiles of eolian earthy red silty clay and loess of the middle of the Late Miocene to Holocene age have been studied and correlated. A complete summary profile with projected isotopic ages and fossil-bearing beds has been assembled. The profile is subdivided into 1.0}stratigraphic units proceeding from the lower (older) to the upper (younger) one. The character of mammalian assemblages contained in each unit was analyzed and the corresponding pa- leo-climatic environments were deduced. The environmental character of each period and the change from the middle of the Late Miocene at about 8.0 Ma B.P. up to the Holocene progressed from the hot semiarid and semi-moist, warmer-moist, warm-moister of the Late Miocene. To slightly less warm moist, cool-dry, slight-warmer-moister of the Pliocene; later the cool to cold dry periods alternated frequently with the mild semiarid and semi-moist periods of the Quaternary. Vegetation progressed from the grasslands with sparse woods, wooded shrub-grasslands and subtropical forest-grasslands of the Late Miocene age to sparse grasslands and dry grasslands of the Pliocene; and to sparse grasslands, dry grasslands and tundras of the Quaternary. The climate changes in the Neogene were of low-amplitute in a generally warm-humid background. Those of the Quaternary were of higher am- plitude with a longer phase. Cool or cold dry and slightly warm semiarid and semi-moist climates al- ternated on a generally cool-dry background. The tendency since the start of the Quaternary was the change to more northern and western shift in the Loess Plateau, with progressively cooler and dryer conditions. The dramatic uplift of the Qinghai-Xizang (Tibet) Plateau and the forming and expansion of the Arctic ice sheet might be the main reasons of the more pronounced changes in the Quaternary.

关键词： paleoenvironment, mammalian fossils, eolian red clay-loess sequence, Loess Plateau.

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Characteristics and origins of primary fluids and noble gases in mantle-derived minerals from the Yishu area,Shandong Province,China

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Science China Earth sciences 2006年第1期49卷 77-87页

作者： MA Jinlong1.2. TAO Mingxin2.3 & YE Xianren2.1. Resources and Environmental School, Lanzhou University, Lanzhou 730000, China 2. Key Laboratory of Gas Geochemistry, institute of {1. and Geophysics, Chinese {2. of sciences, Lanzhou 730000, China 3. College of Resources Science & Technology, Beijing Normal University, Beijing 1.0875, China 1. Resources and Environmental School Lanzhou University Lanzhou 730000 China 2. Key Laboratory of Gas Geochemistry Institute of Geology and Geophysics Chinese Academy of Sciences Lanzhou 730000 China 3. College of Resources Science & Technology Beijing Normal University Beijing 100875 China

Fluids and noble gases of mantle-derived materials are important tracers forthe mantle information. Compositions of primary fluids and noble gases in mantle-derived mineralsfrom the Yishu area, Shandong Province, China, were tested by the methods of heat-bursting andheat-melting respectively. The fluids are mainly composed of CO_2. CO and H_2. which account forabout 90% of the total, and are similar to the mantle-derived rocks from other areas of easternChina; ratios of ~3He/~4He in almost all samples range from 0.82.Ra to 2.74 Ra, whereas^(40)Ar/^(36)Ar from 2.9.5 to 758.8. Both ranges are much lower than those of the typical oceanmantle-derived samples (such as MORB) and primarily reflect the influences of the atmosphericcomponents and the radiogenic isotopes. Ratios of C/~3He range from 2..6 x 1.~9 to 1.50 x 1.~9,N_2.Ar from 92. to 5661.0} and N_2.~3He from 2.5 x 1.~9 to 2. x 1.~9, similar to those in westernUnited States and New Zealand which belong to the tectonic plate collision regions. The ratios fallin the intersect of mantle-crust-atmosphere in the comprehensive tracer-charts, reflecting theinfluences of the atmosphere and the crusts with organic components. Our results suggest that thecomposition of the primary fluids and the isotopic ratios of the noble gases may either reflect theevolution process of mantle-derived rocks connected with the rise and eruption of magma, or theinfluence of the ancient subduction-plate on the continental mantle of this region.

关键词： noble gases, primary fluids, mantle-derived minerals, Yishu area.

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Glacial atmospheric CO_(2. decline in association with decrease of marine sedimentary phosphorus

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Science China Earth sciences 2006年第3期49卷 322-330页

作者： WENG Huanxin1. ZHANG Xingmao1. WU Nengyou2. WANG Ying1. CHEN Lihong1. ZHONG Hexian2.& QIN Yachao1.1. institute of Environment & Biogeochemistry, Zhejiang University, Hangzhou 31.02., China 2. Guangzhou Marine {1. Survey, CGS, MLR, Guangzhou 51.760, China 1. institute of Environment & Biogeochemistry Zhejiang University Hangzhou 310027 China 2. Guangzhou Marine {1. Survey CGS MLR Guangzhou 510760 China

The environmental and biogeochemical information extracted from the sediments col- lected from the northern shelf of the South China Sea shows that terrigenous inputs of phosphorus into the sea remained relatively constant, and the variation of phosphorus contents at different depths was caused by climatic and environmental changes. The findings also suggest that the vertical varia- tion of phosphorus content was opposite to those of calcium carbonate and cadmium, and the func- tional correlation between CO2.and PO43? in seawater was given by calculating the chemical equilib- rium, indicating that the accumulation of marine sedimentary phosphorus may have something to do with the variation of atmospheric CO2. The decreased phosphorus accumulation as well as the cor- respondingly-increased calcium carbonate content might be one of key factors causing glacial at- mospheric CO2.decline.

关键词： sedimentary phosphorus, calcium carbonate, atmospheric CO2. northern shelf of the South China Sea, biogeochemistry.

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A new method for spatio-temporal prediction of rainfall-induced landslide

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Science China Earth sciences 2006年第4期49卷 421-430页

作者： DING Jixin1.2. YANG Zhifa2. SHANG Yanjun2. ZHOU Shenghua1.& YIN Juntao3 1. China Non-ferrous Metals Resource geological Survey, Beijing 1.001.0} China {1. and Geophysics, Chinese {2. of sciences, Key Laboratory of Engineering Geomechanics, Beijing 1.002., China 3. School of Geoscience & Environmental Engineering, Central South University, Changsha 41.083, China 1. China Non-ferrous Metals Resource geological Survey Beijing 100012 China 2. institute of geology and Geophysics Chinese Academy of Sciences Key Laboratory of Engineering Geomechanics Beijing 100029 China 3. School of Geoscience & Environmental Engineering Central South University Changsha 410083 China

geological condition and rainfall are two most principal conditions inducing landslides in the Chongqing region. By analyzing the forming conditions of rainfall-induced landslides, a new method for spatio-temporal prediction of rainfall-induced landslide is brought forward on the basis of grading and overlapping geological condition and rainfall factor in this paper. At first, semi-quantitative assessment and grading for the geological condition of a certain area or slope can be carried out with the multi-factor interactive matrix. Then the severity of rainfall in that area is grading according to the maximum daily rainfall and the total rainfall in a rainfall course. Finally, the “landslide probability judgement factor” can be worked out through grading and overlapping “geological condition influenc- ing factor” and “rainfall influencing factor”, by which the landslide can be graded into 4 grades, they are landslide extremely easily happening, landslide easily happening, landslide difficultly happening and landslide hardly ever happening respectively. More accurate spatio-temporal prediction of rain- fall-induced landslides can come true on the ground of detailed geological survey of some dangerous slopes in an area and more precise weather forecast. Finally, the reliability and feasibility of carrying out the spatio-temporal prediction of rainfall-induced landslides with the method of “two factors” grading and overlapping are validated by the example of Jipazi landslide.

关键词： rainfall-induced landslide, geological condition, rainfall, two factors, grading and overlapping, interactive matrix, spatio-temporal prediction.

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Zijinshan-Bitian Cu-Au-Mo orefield, SW Fujian——An example of gold-rich PCS zoning

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Chinese Science Bulletin 1999年第S2期44卷 134-135页

作者： QI Jianzhong~1, LI Zhaonai~2. ZHANG Dequan~3, FANG Xiheng~4 and XIAO Huiliang~1 1. Nanjing institute of {1. and Mineral Resources, Chinese {2. of geological sciences, Nanjing 2.0016, China 2. institute of geology, Chinese {2. of geological sciences, Beijing 1.0037, China 3. institute of Mineral Deposits, Chinese {2. of geological sciences, Beijing 1.0037, China 4. institute of {1., Ministry of Nuclear Industry, Beijing 100013, China Nanjing institute of {1. and Mineral Resources Chinese Academy of Geological Sciences Nanjing 210016 China institute of {1. Chinese Academy of Geological Sciences Beijing 100037 China institute of Mineral Deposits Chinese Academy of Geological Sciences Beijing 100037 China institute of {1. Ministry of Nuclear Industry Beijing 100013 China

THE Zijinshan-Bitian Cu-Au-Mo orefield is spread to north of the Shanghang County, SW *** geological structure it is located at the plunging end of NE-trending Xuanhe anticlinorium, in the NE rim ofthe NW trending Shanghang volcano-sedimentary basin. Orefield basement is composed of the Archean-Middle Proterozoic low-grade metamorphic rock formations, containing marine basic metavolcanic sequenses. Lower Cretaceous subaerial volcanic rocks of andesite-trachy andesite-rhyolite composition fill inthe volcano-sedimentary basin. Pre-mineralization granitic batholith dated 1.5Ma（Rb-Sr）and 1.7Ma（U-Pb） occupies the axial part of the plunging anticlinorium, which was regarded as crust-remelting typegranitoids. Mineralization-affiliated subvolcanic dacite porphyrite, co-volcanic granodiorite and quartzdiorite porphyrite （1.{1.{1.Ma（Rb-Sr）, Sr1./sub> = 0.708 9） belong to syntactic type in genesis and

关键词： gold-rich porphyre copper system zoning Fujian Zijinshan.

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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, {1. of Geochemistry, Chinese {1. of {2., Guiyang 550002. China 2. Department of geology, China University of Geo{2., Beijing 1.0083, China 3. Department of geology, Peking University, Beijing 1.0871. China 1. Laboratory of Material in the Earth’s Interior Institute of Geochemistry Chinese Academy of Sciences 550002 Guiyang China 2. Department of {1. 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.

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Lead isotopic characteristics of the Xikuangshan superlarge Sb deposit and their geological implications

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Chinese Science Bulletin 1999年第S2期44卷 52-53页

作者： PENG Jiantang~1. HU Ruizhong~1.and ZOU Liqun~2.1. {1. of Geochemistry, Chinese {1. of {2., Guiyang 550002. China 2. Xikuangshan Mining Bureau, Lengshuijiang 41.502. China institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China Xikuangshan Mining Bureau Lengshuijiang 417502 China

THE Xikuangshan Sb ore deposit located in the central part of Hunan Province, China, is the only superlarge Sb deposit so far reported in the world, and is titled as the antimony capital of the world. The strataexposed in the Xikuangshan orefield are only Devonian to Permian Series. Except for a lamprophyre dykeseen in the eastern part, no igneous rocks outcrop within or around the mining district. Orebodies occurdominantly in the Devonian Shetianqiao Formation （D3s） and subordinately in the Qiziqiao Formation（D2./sub>q）. The orebodies usually appear stratiform and stratoid in shape and are rather constant in boththickness and grade. The compositions of ores are simple. The metallic mineral is stibnite and the gangueminerals include quartz and calcite, with minor amounts of fluorite, barite and secondary gypsum. Theores are dominated by the quartz-stibnite type, the quartz-calcite-stibnite type and the

关键词： lead isotope Xikuangshan superlarge Sb deposit Hunan.

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Compositions of heavy minerals in Northeastern China sandlands and provenance analysis

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Science China Earth sciences 2007年第11期50卷 1715-1723页

作者： XIE Jing1.2.& DING ZhongLi1.1.{1. of {1. and Geophysics, Chinese {2. of sciences, Beijing 1.002., China 2.Graduate University of Chinese {2. of sciences, Beijing 1.0049, China 1. institute of {1. and Geophysics Chinese Academy of Sciences Beijing 100029 China 2. Graduate University of Chinese {1. of {1. Beijing 100049 China

Sand samples deposited since the Last Glacial Maximum (LGM) from the Hulun Buir, Horqin and Otin-dag sandlands were measured for their assemblages of heavy minerals and chemical compositions of detrital garnets and tourmalines. Heavy mineral assemblages of these three sandlands consist mainly of garnet, ilmenite, epidote and minor amphibole and magnetite. Garnets consist mainly of high Mg type-A ones (58% on average), and minor type-B ones. Toumalines are mainly composed of Mg-rich and minor Fe-rich ones. Compared with those of central-southern Mongolia and central Tarim, these three sandlands are derived from the Phanerozoic rocks of the Central Asian Orogenic Belt and the Archean and Paleoprotorozoic basement rocks of the North China Craton. Our results provide direct evidence that the present-day sands may be reworked from LGM ones. Differences of heavy mineral composi-tions occur between the samples of the three sandlands and Taklimakan Desert, indicating that the material of the western arid regions contributes little to the eastern sandlands.

关键词： heavy minerals,provenance,Northeastern China,garnet,tourmaline

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The reconstruction and interpretations of lake status at 6 ka and 1. ka *** inland mainland Asia

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Chinese Science Bulletin 1998年第14期43卷 1145-1157页

作者： QIN Boqiang 1. SHI Yafeng 1.and YU Ge 2. 3 1. Nanjing {1. of Geography & Limnology, Chinese {1. of {2., Nanjing 2.0008, China 2. Dynamic Palaeoclimatology, Lund University, PO Box 1.7, S 2.1.00, Lund, Sweden 3. Department of Nanjing institute of Geography & Limnolagy Chinese Academy of Sciences Nanjing China Dynamic Palaeoclimatology Lund University Lund Sweden Department of geology and Ocean {1. Nanjing University Nanjing China

By means of survey of literature through compilations of sedimentological, biogeological and geomorphologic data, the inland lake level changes in arid or semi arid mainland Asia at 6 and 1. ka B.P. have been reconstructed. The results showed that the lakes from western and northwestern Asia were characterized by very high water levels at 1. ka B.P., but low or intermediate water stands at 6 ka B.P. The high lake level in this region was associated with the southward displacement of westerlies, therefore, the extent of the high lake stand indicated the southern flank of westerlies during the glaciation. Conversely, the lakes from the eastern and southern Asia registered comparative low levels at 1. ka B.P. and significantly high one at 6 ka B.P. The lowering of lake level at 1. ka B.P. was caused by the weakened summer monsoon and the high lake level at 6 ka B.P. by the enhanced summer monsoon induced by the enlarged thermal contrast between land and ocean. The extent of high lake levels indicated the northern boundary of monsoon expansion. Between the above two regions, there is a climatic transitional zone in the Central Asia where the lake behavior was close to that in southeastern Asia at 6 ka B.P. but became similar to that in northwestern Asia at 1. ka B.P. Thus this zone became a transitional sector from the monsoon to the westerlies.

关键词： lake status inland mainland Asia westerlies monsoon.

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