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Sm-Nd isotopic geochronologyof the Yinachang Fe-Cu-REE deposit at Wuding, Yunnan Province and its genetic significance

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Science Bulletin 2005年第18期 124-130页

作者： YANG Yaomin1,2.3. TU Guanzhi1, HU Ruizhong1 & SHI Xuefa2.1. institute of {2., chinese Academy of Sciences,{3. 2. The Key Laboratory of Marine Sedimentology and Environmental Geology, The First institute of Oceanography, SOA, Qingdao 2.6061, china 3. Northwest Geological Exploration Bureau, CNNC, Xi’an 710054. china

Sm-Nd isotope systematics of ores and fluorites places precise time constraints on REE mineralization of the Yinachang Fe-Cu-REE deposit in Yunnan Province which occur in the Proterozoic Kunyan group. The ore-related fluorites contain high abundant REE, and show a strong enrichment of LREE and a positive Eu anomaly, which is in marked contrast to post-ore fluorites that are HREE en-riched. The Sm-Nd isochron ages of the ores and fluorites are 153.±4. Ma and 1617±100 Ma, respectively, and calculated εNd(t) are ?4.6 and ?3.2. Accurate age determinations of the mineralization demonstrate that the REE mineralization took place during early Mesoproterozoic. Together with other geological evidence from the ore deposit, the primary REE-bearing ore-forming fluids are suggested to have been derived from the Enriched Mantle, and the Yinachang Fe-Cu-REE ore deposit is of volcanic exhalation- hydro-thermal sedimentary origin. This study also imply that the sudden large-scale REE mineralization in the Mesoprotero-zoic epoch may have been induced by alkaline-rich anoro-genic magmatism which occurred at marginal rifts of the continent in the Mesoproterozoic.

关键词： Kunyang rift Yinachang Fe-Cu-REE deposit fluorite Sm-Nd isotopic systematics Mesoproterozoic.

Distribution of mercury species in water and sediments in Caohai Lake, Guizhou Province

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Acta Geochimica 2006年第S1期 153-154页

作者： Xiaoli QIAN1,2. Xinbin FENG1, Xiangyang BI1,3.1 State Key Laboratory of Environmental geochemistry, {2. of geochemistry {3. Academy of Sciences, guiyang 550002. china 2.Guizou University, guiyang 55002., china 3.Graduate School of the {3. Academy Sciences, Beijing 10003.,china

Gold redistribution in Shangmanggang red-clay gold deposit, western Yunnan Province, china

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chinese Science Bulletin 1999年第S2期44卷 214-216页

作者： YANG Zhusen, LI Hongyang, GAO Zhenmin, LUO Taiyi, RAO Wenbo and DING Zhenju Open Laboratory of Deposit geochemistry, Iustitute of Geoehemistry, chinese Academy of Sciences,{2. Open Laboratory of Deposit geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China

AFTER the discovery of lateritic gold deposits in the world during the 1980s, many similar oxidized golddeposits have been discovered in southern china since 1989. Because the incomplete lateritization ofthe regolith compared with the laterite, these oxidized gold deposits were called the red-clay type gold deposits by Prof. Tu Guangzhi. The Shangmanggang gold deposit is a typical representative of the red-claytype gold deposit in western Yunnan Province. 1 Geology, climate, and geomorphology The Shangmanggang red-clay gold deposit is located in Luxi region, between Zhefang and LuxiCenozoic basins along the Longling-Runli Fault trending northeast. The northwestern flank of the basinsconsists of the Proterozoic Gaoligong Group composed of greenschist to amphibolitic metamorphic

关键词： gold redistribution red-clay type of gold deposit Shangmanggang gold deposit Yunnan.

Changes or soil microbial biomass carbon and orgamc carbon with sea level elevation increasing in soils of mountainous areas, Southwest china

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chinese Science Bulletin 1999年第S2期44卷 116-117页

作者： PIAO Hechun, HONG Yetang and YUAN Zhiyun State Key Laboratory of Environmental geochemistry, institute of geochemistry, {3. Academy of Sciences,{4.

SOIL organic matter, a major factor affecting agroecosystem stability, is controlled by many parameters. Itis well understood that cultivation practive would lead to a decrease in organic matter content of ***, small gradual changes in total soil organic matter may be difficult to monitor and detect in theshort term because of generally high background carbon levels and natural variability of soils. On ashort-term scale the measurement of the living fraction of soil organic matter, i.e. microbial biomass C,can reveal early changes in soil organic matter. Our work is to identify the relationship of soil organic Cand changes in microbial biomass C with sea-level elevation increasing. Twelve terrace fields on the slopes at different altitudes above sea level were chosen as sample localities. The terrace fields, different in size, approximately 10 m^2. were used for growing maize. Those sam-

关键词： soil microbial biomass carbon organic carbon soils.

7~Be: A Geochemical Tracer for Seasonal Erosion of Surface Soil in Watershed of Lake Hongfeng, Guizhou, china

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Pedosphere 1996年第1期6卷 23-28页

作者： BAI ZHANGUO WAN GUOJIANG WANG CHANGSHENG WAN XI HUANGRONGGUI P.H. SANTSCHIZ and M. BASKARANZ(1￣State Key Lab. Of Environmental geochemistry, institute of geochemistry, {3. Academy of Sciences,{4. 550002.(china))(2.Department Of Marine Scien State Key Lab. of Environmental geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550005 China Department of Marine Sciences Texas a K M University Galveston TX 77551 United States

e penetrative depth in undisturbed surface soil is within 4.mm.7￣Be activity shows exponential decrease with soil depth, which is expressed as a diffusion process.7￣Be penetrative depth in undisturbed surface soil is apparently deeper in the fall (0.2.-0.3. g cm￣(-2. than in the spring (0.11-0.2. g cm￣(-2. at the same site; Whereas, ￣7Be apparent activity at the top of surface soil is higher in the spring (0.3.2.2.Bq g￣(-1_) than in the fall (0.2.0.5 Bq g￣(-1) at the same site. The ￣7Be inventory (189-54. Bq m￣(-2. changes with both locations and seasons. Although the ￣7Be flux to the earth's surface increases with amount of precipitation, its maximum inventory in the soil profiles decreases to 3.%-4.% after the rainy period. Calculated by the diffusion equation, the erosion and accumulation rates of soil particles are agreeable with the observation in situ., which shows that the rates in fall are 1.5 times those in spring. The eroded soil particles almost all have been removed on the tablelands rather than transported into the drainage system. This indicstes that the soil erosion process in the karst region is only partial transportation within a short distance.

关键词： e erosion trace Lake Hongfeng watershed surface soil

P-Wave Velocity in Rocks of Dabieshan, china at High Pressure and High Temperature: Constraints for Composition of Lower Crust and Crust-Mantle Recycling

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Journal of Earth Science 1999年第4期18卷 295-298页

作者： Zhao Zhidan Zhou Wenge Xie Hongsen Guo Jie Xu Zuming(institute of geochemistry, {2. Academy of Sciences, {3. {4.Zhang Zeming(institute of Geology, {2. Academy of Geological Sciences, Beijing 10003.) institute of geochemistry Chinese Academy of SciencesGuiyang 550002 institute of Geology Chinese Academy of Geological SciencesBeijing 100037

P-wave velocities in the rocks of Dabieshan, central china were measured at pressures up to 5.0 GPa and temperatures up to 1 3.0℃. The ultrahigh pressure eclogites have the highest density and P-wave velocity (Vp) and lower anisotropy. Pressure derivatives of the eclogites range from 0. 2. to 0. 3. km. s-1 GPa-1. Average temperature derivative of the eclogites is - 3. 4.×10-4.km. s-1. °C -1. The density and VP of the eclogites imply that there will be two united possibilities related to crust-mantle recycling after the eclogite formed in the deep lithosphere. One is that some eclogites in the deep lithosphere were detached and sunk into deeper mantle due to their denser density. Another is that some eclogites returned to the crust and exposed to the *** amounts (2.) of eclogites may be still exist in the deep crust beneath Dabieshan based on our calculation.

关键词： eclogite P-wave velocity density high pressure high temperature lower crust

Using the dual isotopes approach to identify the nitrate sources of karst groundwater, guiyang, Southwest china.

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Acta Geochimica 2006年第S1期 173-174页

作者： Siliang LI, Congqiang LIU, Yunchao LANG The State Key Laboratory of Environmental geochemistry, institute of geochemistry, {3. Academy of Sciences,{4.

Isotopic evolution of the terminal Neoproterozoic and early Cambrian carbon cycle on the northern Yangtze Platform, South china

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Progress in Natural Science:Materials International 2003年第12期 62-65页

作者： GUO Qingjun 1,2. *, LIU Congqiang 1, Harald STRAUSS 3.and Tatiana GOLDBERG 3.1. {2. of geochemistry, {4. Academy of Sciences,{3. 2. Graduate School, {4. Academy of Science, Beijing 100018, china 3. Geologisch Palontologisches Institut, Westflische Wilhelms Universitt Münster, 4.14. Münster, Germany) institute of geochemistry，{2. Academy of Sciences，{3. {4.china Graduate School，chinese Academy of Science，Beijing 100018，china institute of geochemistry，{2. Academy of Sciences，{3. {4.china Geologisch-Palaontologisches Institut，Westfalische Wilhelms-Universitat Münster，4.14. Münster，Germany

Profound geotectonic, climatic and biological changes occur during the terminal Neoproterozoic and its transition into the early Cambrian. These are reflected in temporal variations of the chemical and isotopic composition of seawater. We are studying a sequence of sedimentary rocks at the Shatan section, northern Yangtze Platform, Sichuan Province of china. This succession comprises, in ascending stratigraphic order, predominantly calcareous sediments of the Sinian upper Dengying Formation and black shales of the lower Cambrian Guojiaba Formation (time equivalent of Niutitang Fm.). Paleoenvironmental setting represents shallow water shelf deposits. The objective of our study is to provide temporal records for the isotopic compositions of organic and carbonate carbon throughout this time interval. Organic carbon isotope values display a range between -3..8‰ and -3..1‰ with clear stratigraphic variations. Carbonate carbon isotope data vary between -3.5‰ and +0.5‰. These secular variations are interpreted to reflect perturbations of the global carbon cycle, specifically changes in the fractional burial of organic carbon. However, local conditions have further affected the isotopic signals.

关键词： terminal Neoproterozoic Early Cambrian carbonate and organic carbon isotopic composition Yangtze Platform Shatan section.

Fallout radionuclides (~7Be and ^(13.)Cs) in surface soils and lake sediments in west Yunnan and central Guizhou, china

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chinese Science Bulletin 1999年第S2期44卷 125-126页

作者： BAI Zhanguo~(1,2. and WAN Guojiang~1 1. State Key Laboratory of Environmental geochemistry, institute of geochemistry, {3. Academy of Sciences,{4. 2. State Key Laboratory of Plant Nutrition Research of {3. Ministry of Agriculture institute of Soil and Fertilizer, {3. Academy of Agricultural Sciences, Beijing 100081, china

WEST Yunnan and central Guizhou with variable altitudes and similar latitudes, located in the Yunnan-Guizhou Plateau of the eastern slope uplifting Himalayas, were selected as study areas in this note. Thetwo areas consist mainly of carbonate rocks discontinuously covered by similar soil types with severe soiland water loss except Lugu Lake catchment. Climate of the study areas is subtropical monsoon, apparently influenced by mingled southeastern monsoon and southwestern monsoon with abundant *** study is to comparatively describe distribution and inventory of 7Be and 13.Cs in the sediments of Erhai Lake, Lugu Lake and Hongfeng Lake as well as in 2. surface soil profiles of their *** results have shown that: （i） In all the soil profiles, 7Be activities decrease exponentially with soil depth. 7Be apparent ac-

关键词： radionuclides soils sediments china.