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Characteristics of Ore-Forming Fluids of Gold Deposits in Daqingshan District,Inner Mongolia,China

International Journal of Minerals,Metallurgy and Materials 1999年第2期13卷 77-82页

作者： Jiuhua Xu YulingXie Dayi Qian Rufu Dine Jianping Li (Resource Engineering School, University of Science and Technology Beijha Beijing 100083, China) (China University of Geosciences, Beijing 100083, China) Resource Engineering School University of Science and Technology Beijing Beijing 100083 China China University of Geosciences Beijing 100083 China

Locatedinthemid-westoflimerMongolia.Daqingshandistricthasmanygolddepositsoccurringalongaeast-weststrikingductileshearzonewithinagreelt,whichismainlycomposedoftheArcheanWulashangroup.Thehydrothermalmineralizationcanbedividedintofourstages:(1)pyrite-quartz,(2)quartz-Pyrite,(3)polymetallicsulfidesand(4)carbonates-quartz.Themajormetalylicmineralsintheoreofgold-bearingveinsarenativegold,electrum,pyrite,chalcopyriteandgalena,buttheganguemineralsaremainlyquartz,secondarilysericite,ankeriteandexcite.Prinipalalterationpatternsinthegolddepositsaresericithation,silicification,pyritizationcarbonatizationandchlorization.Aninvestigationonfluindinclusionsshowsthattheore-formingfluidswerelowinsalinitieandhighinCO2content,MeasuredδDoffluidinclusionsinquartzfromtheoreveinsrangesfrom-65‰to-104‰,butδ18Oquartzfrom10.0‰to12.8‰.Thesedatashowthatthewaterinhydrothermalfluidprecipitatingtheorebodiescouldhavebeenmainlymagmaticwaterandmetamorphicwaterbutlocalmeteoricwatermighttakepartinthelatemineralization.δ13Cfromfl

关键词： fluid inclusions isotope composition gold deposit Daqingshan area

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Interactive effects of elevated CO2 and nitrogen fertilization levels on photosynthesized carbon allocation in a temperate spring wheat and soil system

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Pedosphere 2021年第1期31卷 191-203页

作者： Yu ZHAO Chao LIANG Shuai SHAO Jie LI Hongtu XIE Wei ZHANG Fusheng CHEN Hongbo HEI Xudong ZHANG lustinte of Appied Eeology Chinese Academy of SciencesShenyang 10016China Umiversily of Chimese Academy of Sciemces Bejing 1000China Jiongi Prorincial Ker Labonalory of Silvic wlar .Jiangui Agricnlarol Univerniys Nanchang 30045China

Increasing atmospheric CO2 concentration impacts the terrestrial carbon(C) cycle by affecting plant photosynthesis, the flow of photosynthetically fixed C belowground, and soil C pool turnover. For managed agroecosystems, how and to what extent the interactions between elevated CO2 and N fertilization levels influence the accumulation of photosynthesized C in crops and the incorporation of photosynthesized C into arable soil are in urgent need of exploration.We conducted an experiment simulating elevated CO2 with spring wheat(Triticum aestivum L.) planted in growth chambers.13C-enriched CO2 with an identical 13C abundance was continuously supplied at ambient and elevated CO2 concentrations(350 and 600 μmol mol-1, respectively) until wheat harvest.Three levels of N fertilizer application(equivalent to 80, 120, and 180 kg N ha-1 soil) were supplied for wheat growth at both CO2 concentrations. During the continuous 62-d 13CO2 labeling period, elevated CO2 and increased N fertilizer application increased photosynthesized C accumulation in wheat by 14%–24% and 11%–20%, respectively, as indicated by increased biomass production, whereas the C/N ratio in the roots increased under elevated CO2 but declined with increasing N fertilizer application levels. Wheat root deposition induced 1%–2.5% renewal of soil C after 62 d of 13CO2 labeling. Compared to ambient CO2, elevated CO2 increased the amount of photosynthesized C incorporated into soil by 20%–44%. However, higher application rates of N fertilizer reduced the net input of root-derived C in soil by approximately 8% under elevated CO2. For the wheat-soil system, elevated CO2 and increased N fertilizer application levels synergistically increased the amount of photosynthesized C. The pivotal role of plants in photosynthesized C accumulation under elevated CO2 was thereby enhanced in the short term by the increased N application. Therefore, robust N management could mediate C cycling and sequestration by influencing the interactions between plants and soil in agroecosyst

关键词： C cycling C sequestration continuous 13C-enriched CO2 labeling growing season isotope composition N management wheat tissue biomass

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Characteristics of Stable isotopes in an Inland Lake and Their Implications for Water Management in Northwestern China

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Journal of Water Resource and Protection 2016年第6期8卷 631-641页

作者： Honghua Zhou Weihong Li Yun Wang Zhaoxia Ye State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and Geography Chinese Academy of Sciences Urumqi China Xinjiang Normal University Urumqi China

Bosten Lake is the largest inland freshwater lake in China, functioning as a critical control and allocation facility for agricultural, industrial, ecological and social development in southern Xinjiang in northwestern China. The distribution of stable isotopes, spatial and temporal variations of δ18O, and hydrograph separation of Bosten Lake and its principal recharge rivers—the Kaidu River and the Huangshuigou River—were analyzed using isotope composition. Hydrograph separation indicated that Bosten lake water comprised four components as follows: river runoff, groundwater, agricultural and industrial drainage, and local precipitation. Their contributions were 31%, 35%, 25%, and 9%, respectively. Irrigation drainage and industrial wastewater, enriched high TDS, were the main factors affecting the water quality of Bosten Lake. The δ18O of lake water, which was significantly reduced compared with river water, remained below the local meteoric water line (LMWL), indicating strong evaporation in the lake, especially during summer. The spatial and temporal distribution of δ18O exhibited slow water circulation in the lake. Both the Kaidu River and the Huangshuigou River depend on alpine precipitation and glacier snow, especially the Kaidu River, where ice-snow-melt water accounts for 43% of the river runoff. These rivers are sensitive to climate change. The Bosten Lake inflows would be reduced by the decrease in river runoff and groundwater under future climate change. To improve water quality and reduce evaporative loss, the amount of wastewater should be strictly restricted by local government, and water diversions from Bosten Lake should be concentrated between May and September.

关键词： isotope composition Spatial and Temporal Variation Hydrograph Separation Bosten Lake Arid Area

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