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Distributions of fatty acids in a stalagmite related to paleoclimate change at Qingjiang in Hubei,southern China

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Science China Earth Sciences 2005年第9期48卷 1463-1469页

作者： XIE Shucheng1,HUANG Junhua1,WANG Hongmei2,YI Yi1,HU Chaoyong1, CAI Yanjun3.& CHENG Hai4.1. Faculty of Earth Science,China university of Geosciences,Wuhan 4.0}074.China 2. School of Environmental Studies,China university of Geosciences,Wuhan 4.0}074.China 3. SKLLQG,Institute of Earth Environment,Chinese Academy of Sciences,Xi’an 710075,China 4. Department of geology and {3.,university of minnesota,mn5.455,USA 1. Faculty of Earth Science China University of Geosciences 430074 Wuhan China 2. School of Environmental Studies China University of Geosciences 430074 Wuhan China 3. SKLLQG Institute of Earth Environment Chinese Academy of Sciences 710075 Xi’an China 4. Department of geology and geophysics University of Minnesota 55455 MN USA

Fatty acids extracted from a subtropical stalagmite at Qingjiang in Southern China’s Hubei Province were analysed using gas chromatography-mass spectrometry. These n-alkanoic acids range from C14.to C26 in carbon number, maximizing at C16, with a second dominance at C22. In contrast to the stalagmite analysed, the overlying soils are characterized by the dominance of heavy-molecular-weight homologues (>C20). The n-fatty acids in the stalagmite were proposed to be contributed by both the soil ecosystems and the microbes harboring in the percolating water and the cave. The ratios of unsaturated to saturated n-fatty acids (C16:1i/C16:0, C18:1/C18:0) appear to show trends comparable with the oxygen isotope records of the stalagmite carbonate, with enhanced values associated with the cold episode such as Heinrich event 1. This paleoclimate-dependent record of the n-fatty acids might reflect microbial changes in physiology and activity in response to the temperature. This record shows somewhat difference from the previous paleoclimate signal extracted from n-alkanols and n-alkan-2-ones of the same stalagmite. The acid record fails to document the well-known Younger Dryas event which was effectively shown by the latter two biomarkers derived from soil ecosystems. This discrepancy might result from the changing biogeochemical impact on different lipid fractions as well as the varied organism populations in different ecosystems.

关键词： biomarker, ecosystem, microbe, speleothem, paleoclimate, Quaternary.

A possible Younger Dryas-type event during Asian monsoonal Termination 3

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Science China Earth Sciences 2006年第9期49卷 982-990页

作者： CHEN Shitao1, WANG Yongjin1, KONG Xinggong1, LIU Dianbing1, CHENG Hai2 & R.L. Edwards2 1. College of Geography Science, Nanjing Normal university, Jiangsu Key Laboratory of Environmental Change and Ecological Construction, Nanjing 210097, China 2. Department of geology and geophysics,{3.,{4. mn5.455, USA 1. College of Geography Science Nanjing Normal University Jiangsu Key Laboratory of Environmental Change and Ecological Construction Nanjing 210097 China 2. Department of geology and geophysics University of Minnesota Minneapolis MN 55455 USA

Seven U-Th dates, 560 δ 18O data and microscopic sequences were measured for sta- lagmites from two high-altitude caves in Shennongjia area, Hubei Province. Variations of the de- cadal-resolution stalagmite δ 18O record from Swan Cave (1600 m elevation) reflect large spatial changes in circulation strength and precipitation of Asian monsoon. The evidence comes from a great similarity among the stalagmite δ 18O records from Nanjing, Jiangsu Province; Libo, Guizhou Province and here studied area during the last deglaciation, including a part interval of Younger-Dryas event and Bolling-Allerod. A 3.-year-resolution stalagmite δ 18O record from Yongxing Cave (14.0 m eleva- tion), 70 km away from Swan Cave, reveals a rapid transition of Asian monsoon climate during Ter- mination 3.at about 24.±5 kaBP. Based on 3.U-Th dates and about 5000 continuous annual bands, a millennial dry episode has been observed during Asian monsoonal Termination 3.from the Yongxing δ 18O profile. With respect to its structure, duration and transition, the dry reversal, as indicated by our stalagmite δ 18O record, generally agrees with the pattern of the YD event well-expressed in the Chi- nese stalagmite δ 18O records. This YD-type event is characterized by a large decrease in δ 18O value as much as 2.3.‰, more than half of the δ 18O excursion between glacial/interglacial periods, and lasts 13.1±59 a determined by the annual counting chronology. After this event, the monsoon climate shifted abruptly into the interglacial period within 74.4.a. Our data corroborate the view that the re- peated occurrence of YD-type event was not an “accident”, possibly resulted from the coupling of ice-sheet and oceanic/atmospheric circulations.

关键词： stalagmite, Termination 3. Asian monsoon, YD-type event, Shennongjia, Hubei Province.

Nd isotope as the tracer of seawater evolution of early Miocene in the eastern Pacific Ocean

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Chinese Science Bulletin 2003年第B06期48卷 106-110页

作者： LIU Jihua~(1,2,3., CHEN Lirong~1, WANG Yingxi~4.& HAN Jianxiu~5 1. Institute of Oceanology, Chinese Acadcmy of ences, Qingdao 266071. China 2. Key Lab of Marine Sedimentology and Environmental geology, First Institute of Oceanograpgy, State Oceanic Administration, Qingdao 266061. China 3. Graduate School, Chinese Academy of Sciences, Beijing 10003.. China 4. Modern Analysis Center, Nanjing {4.. Nanjing 210093. China 5. Guangzhou Marine Investigation Bureau, Guangzhou 510760. China 1. Institute of Oceanology Chinese Academy of Sciences 266071 Qingdao China 2. Key Lab of Marine Sedimentology and Environmental geology First Institute of Oceanograpgy State Oceanic Administration 266061 Qingdao China 3. Graduate School Chinese Academy of Sciences 100039 Beijing China 4. Modern Analysis Center Nanjing University 210093 Nanjing China 5. Guangzhou Marine Investigation Bureau 510760 Guangzhou China

Fifty-six samples of nannofossil ooze were collected from Core PC5794.in the northern equatorial Pacific at 5 cm intervals. With the methods of mass spectrometer (VG3.4. and ICP, the Nd isotopic compositions (εNd(t)), mn contents and Mg/Sr ratios of carbonate phase have been analyzed. CaCO3.contents of bulk sediments were obtained by dissolution of 0.5 mol/L HCl. Based on these data, the high-resolution εNd(t) profile of seawater in early Miocene with core depth(or time) have been established. The values of εNd(t) range from -6.2 to -2.97 and 4.fluctuation cycles existed during 24.06-22.02 Ma. 4.low εNd(t) values (about -6.4. correspond to high CaCO3.contents, which implicates that there were 4.cold epochs or 4.times of Antarctic Bottom Water activity. They occurred at the time of 24.06 Ma, 23.85 Ma,22.88 Ma and 22.26 Ma, respectively. High εNd(t) values correspond to the high mn contents and high values of Mg/Sr ratio, which indicates the existence of 4.intense hydrothermal activity periods during 24.06-22 Ma, the durations of them are 4.05-23.98 Ma, 23.69-23.15 Ma, 22.74.22.3. Ma and 22.06-22.02 Ma, respectively.

关键词：同位素钕示踪原子海水演化中新世太平洋微化石分光计持续期海水样品

High resolution stalagmite δ18O records over the past 1000 years from Dongge Cave in Guizhou

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Science Bulletin 2005年第10期50卷 1003-1008页

作者： HE Yaoqi1, WANG Yongjin1, KONG Xinggong1 & CHENG Hai2 1. College of Geography Science, Nanjing Normal university, Nanjing 210097, China 2. Department of geology and geophysics, {3. university, Mineapolis mn 5.455, USA College of Geography Science Nanjing Normal University Nanjing 210097 China

Based on MC-ICP-MS U-series dating and stable O-isotope analysis results, a 4.5 years resolution monsoon record over the past 1000 years has been estab- lished for two stalagmites from Dongge Cave, Guizhou. The high resolution oxygen isotope record serves as a proxy for variations in rainfall of Asian southwest monsoon over the Yunnan-Guizhou Plateau. A close relation of the δ 18O record with the ?14. record from tree rings largely reflects impact of centennial-scale solar activity on the monsoon climate changes. The conspicuous decrease in the δ 18O value at AD 1720 indicates an abrupt increase in monsoon rainfall, sug- gesting that an atmospheric-oceanic couple over the tropical Indian Ocean plays an important role in rapid increase of the Northern Hemisphere temperature over the last century.

关键词： cave stalagmite oxygen isotope southwest monsoon solar activity Guizhou.

The *** climate abrupt events in the early and middle Holocene:Stalagmite oxygen isotope record from Maolan,Guizhou,China

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Science China Earth Sciences 2005年第4期48卷 530-537页

作者： QIN Jiaming1, YUAN Daoxian1, CHENG Hai2, LIN Yushi1, ZHANG Meiliang1, WANG Fuxing1, R. L. Edwards2, WANG Hua1 & RAN Jingcheng3.1. The Karst Dynamic Laboratory, IKG, CAGS, Guilin 54.004. China 2. geology and geophysics Department, minnesota {3., mn5.455, USA 3. The Management of Maolan National Nature Reserve, Libo 5584.0, China 1. The Karst Dynamic Laboratory 541004 IKG CAGS Guilin China 2. geology and geophysics Department Minnesota University 55455 MN USA 3. The Management of Maolan National Nature Reserve 558400 Libo China

The isotope records which range from 3.9 kaBP to 15.7 kaBP with an average resolution of 90 a have been obtained from 4. cm to 193.6 cm of the upper part of D4.stalagmite from Dongguo Cave in Libo, Guizhou, by using system TIMS U-series dating and carbon and oxygen stable isotope *** study indicates that the last cold event, the YD (Younger Dryas) event, of the last glacial period was apparently shown in D4.record, which started from 12.80 kaBP and ended in 11.58 kaBP, with a great range of drop in temperature. The end of the last glacial period was consistent with the termination I in oceanic isotope records and was with time limit of 11.3.kaBP. The three most distinct cold events in the early and middle Holocene occurred respectively in 10.91 kaBP, 8.27 kaBP and 4.75 kaBP, with a range of drop in tem- perature reaching 2—5℃. The climate abrupt events in thousand and hundred years scale re- corded in stalagmite δ O can be compared to those in GISP2 ice cores from Greenland in their 18 happening time and the range of their lasting time. The cold events in 8.27 kaBP and 4.75 kaBP can also be compared to CC3.stalagmite records in Ireland, which indicate that climate changes of short range in China monsoon areas, western Europe and polar regions, have the same driv- ing factor. This has a global significance. In addition, the trend of record curves in some time- stages is apparently different, which reflects probably the difference between environment in monsoon climate areas and in polar regions.

关键词： isotope record, climate event, stalagmite, Libo, Guizhou.

Concentration Characteristics and Sources of Chemical Elements in Atmospheric Fine Particles (PM_(2.5)) in Autumn in Xi'an City

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Meteorological and Environmental Research 2011年第4期2卷 5-8页

作者： GAN Xiao-feng1,2, CAO Jun-ji2,3. WANG Qi-yuan4. SHEN Zhen-xing4. XU Hong-mei2 1. Department of Environmental Science and Technology, Xi’an Jiaotong university, Xi’an 71004., China 2. State Key Laboratory of Loess and Quaternary geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710075, China 3. Institute of Global Environmental Change, Xi’an Jiaotong university, Xi’an 71004., China 4. Department of Environmental Engineering, Xi’an Jiaotong university, Xi’an 71004., China

[Objective] The aim was to study the concentration characteristics and sources of chemical elements in atmospheric fine particles (PM2.5) in autumn in Xi’an City. [Method] By means of mini-volume sampler, PM2.5 samples in atmosphere in Xi’an were collected in October 2009, and the concentration characteristics and sources of elements in PM2.5 were analyzed. [Result] The average mass concentration of PM2.5 in atmosphere in autumn in Xi’an City was 168.4. μg/m3.which was higher than that of Beijing and Pearl River Delta area, and the minimum and maximum value were 53.29 and 3.8.16 μg/m3. respectively. The mass concentration of S, Zn, K, Cl, Ca and Fe in PM2.5 was above 1.0 μg/m3. being at high pollution level. In addition, K had obvious correlation with organic carbon (OC) and element carbon (EC), with the correlation coefficients of 0.76 and 0.75 (Pmn and Cr mainly came from earth crust, rock weathering and other natural sources, while anthropogenic pollution sources had great effects on S, Zn, Cl, Pb, Br, Mo, Cd and As which were affected by soil dust and other natural sources slightly, and Cd had the highest enrichment factor and mainly came from metal smelting. In a word, coal combustion, biomass burning, vehicle emissions, metallurgical, chemical industry and dust were the main sources of PM2.5 in autumn in Xi’an. [Conclusion] The study could provide theoretical foundation for the control of urban environmental pollution.

关键词： Atmospheric fine particles Chemical element Enrichment factor Factor analysis China

Rheology of Partially Molten Olivine Aggregates under Water-Saturated Conditions

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Continental Dynamics 1997年第1期 54-62页

作者： BAI Wuming (Institute of geophysics, Chinese Academy of Sciences, Beijing 100101, China) MEI Shenghua David KOHLSTEDT (Department of geology and geophysics,{3.,{4., USA)

The influence of basaltic melt and water content on the high-temperature plastic deformation behavior of olivine aggregates was studied by performing a series of high-temperature creep experiments. The specimens, which are the powder of San Carols olivine plus 1, 4. or 7 wt% MORB, with the grain size of 10-20 μm, were hotpressed. Deformation experiments were conducted in a gas-medium apparatus at a confining pressure of 3.0 MPa and temperature of 13.3.K to 14.3.K. Water was supplied by dehydration of TALC near 1073.K. The hy- droxyl concentration in the samples was determined from Fourier-Transform Infrared (FTIR) spectra.

关键词： partial melting water-saturated conditions rheology high pressure and high temperature

Abrupt climate change of EastAsian Monsoon at 13. kaBP inferred from a high resolu-tion stalagmite δ18O record

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Science Bulletin 2005年第23期50卷 2765-2769页

作者： JIANG Xiuyang1, WANG Yongjin1, KONG Xinggong1,WU Jiangying1, SHAO Xiaohua1, XIA Zhifeng1 & CHENG Hai2 1. College of Geography Science, Nanjing Normal university, Nanjing210097, China 2. Department of geology and geophysics,{3.{4., mn 5.455, USA College of Geography Science Nanjing Normal University Nanjing 210097 China Department of geology and geophysics University of Minnesota Minneapolis MN 55455 USA

23.Th ages and oxygen isotope data of a stalagmite from Shanbao Cave in Hubei Province characterize thEast Asian Monsoon precipitation from 13. to127 ka. Thdecadal-scale high-resolution δ18O record reveals a detailedtransitional process from the Penultimate Glaciation to thLast Interglaciation. As established with 23.Th dates, the agof the Termination II is determined to be 129.5±1.0 kaBPwhich supports the Northern Hemisphere insolation as thtriggers for the ice-age cycles. In our δ18O record, the glacialinterglacial fluctuation reaches about 4., almost the samlevel as in other Asian Monsoon cave stalagmite δ18O recordThe transition of the glacial/interglacial period in our recordcan be recognized as four stepwise stages, among which, arapid rise of monsoon precipitation follows the stage o“Termination II pause”. The rapid rise is synchronous withthe abrupt change of global methane concentration, whichreflects that an increase in both Asian Monsoon precipitationand tropical wetland plays an important role in the globaclimate changes.

关键词： stalagmite high-resolution U/Th age Termination II.

EPR studies of mn^(2+) in the Loess Plateau of central China: Implication for variation of the East Asia summer monsoon

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Chinese Science Bulletin 1998年第1期43卷 72-75页

作者： CHEN Jun\+1, JI Junfeng\+1, SU Yuanxia\+2 and LU Huayu\+3.. Department of Earth Sciences, Nanjing university, Nanjing 210093. China 2. Center of Material Analysis, Nanjing university, Nanjing 210093. China 3. Xi’an Laboratory of Loess and Qu Department of Earth Sciences Nanjing University Nanjing China Center of Material Analysis Nanjing University Nanjing China Xi’an Laboratory of Loess and Quaternary geology Chinese Academy of Sciences Xi’an China

mn 2+ EPR intensity recorded in the Chinese loess_paleosol sequence shows close correlation with magnetic susceptibility and Sr content as well as the oscillation of paleoclimate. Thus mn 2+ EPR signal can serve as an... 详细信息

关键词： paleomonsoon loess paleosol EPR signal of mn 2+