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

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 4.0074.China 2. School of Environmental Studies,China University of Geosciences,Wuhan 4.0074.China 3. SKLLQG,Institute of Earth Environment,Chinese Academy of Sciences,Xi’an 710075,China 4. department of geology and geophysics,University of Minnesota,mn55455,usa Faculty of Earth Science China University of Geosciences Wuhan China School of Environmental Studies China University of Geosciences Wuhan China SKLLQG Institute of Earth Environment Chinese Academy of Sciences Xi’an China department of geology and geophysics University of Minnesota 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.

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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, University of Minnesota, Minneapolis mn55455, {4. College of Geography Science Nanjing Normal University Jiangsu Key Laboratory of Environmental Change and Ecological Construction Nanjing China department of geology and geophysics University of Minnesota Minneapolis 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 30-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 2.30‰, more than half of the δ 18O excursion between glacial/interglacial periods, and lasts 1371±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.

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No apparent lock-in depth of the Laschamp geomagnetic excursion: Evidence from the Malan loess

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Science China Earth Sciences 2006年第9期49卷 960-967页

作者： ZHU Rixiang1, LIU Qingsong1,2, PAN Yongxin1, DENG Chenglong1, ZHANG Rui1 & WANG Xianfeng3 1. Paleomagnetism and Geochronology Laboratory (SKL of Lithosphere Evolution), Institute of geology and geophysics, Chi- nese Academy of Sciences, Beijing 100029, China 2. Institute of geophysics and Planetary geophysics, University of California, Santa Cruz, CA 95064. {4. 3. {4. of geology and geophysics, University of Minnesota, Minneapolis, mn 55455, {4. Paleomagnetism and Geochronology Laboratory (SKL of Lithosphere Evolution) Institute of Geology and Geophysics Chinese Academy of Sciences Beijing China Institute of geophysics and Planetary geophysics University of California Santa Cruz USA department of geology and geophysics University of Minnesota Minneapolis USA

The first-order chronological framework of the long-term Chinese loess/paleosol sequences was based mainly on magnetostratigraphy. However, there remain arguments on the lock-in ages of the major geomagnetic reversals. This study systematically compared the stratigraphic locations of the Laschamp excursion and Henrich events (H4.at～39 ka and H5 at～4. ka) recorded by the Luochuan loess profile in the central Chinese Loess Plateau. Results show that the Lascchamp excursion is bracketed well by these two cold events, and the corresponding estimated age is between about 4..7-4..7 ka, which is close to the widely accepted age of ～4.-4. ka for the ***, our new results do not suggest apparent lock-in effects in the last glacial Malan loess.

关键词： Chinese loess, Laschamp excursion, Henrich event, lock-in depth.

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Geomorphologic evidence of phased uplift of the northeastern Qinghai-Tibet Plateau since 14.million years ago

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Science China Earth Sciences 2004年第9期47卷 822-833页

作者： LU Huayu1, WANG Xiaoyong1, AN Zhisheng1, MIAO Xiaodong1, ZHU Rixiang3, MA Haizhou2, LI Zhen4. TAN Hongbing2 & WANG Xianyan1 1. State Key Laboratory of Loess and Quaternary geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710075 China 2. Qinghai Institute of Salt Lakes, Chinese Academy of Sciences. Xining 810008, China 3. Institute of geology and geophysics, Chinese Academy of Sciences, Beijing 100029, China 4. department of Geography, Qinghai Normal University, Xining 810008, China State Key Laboratory of Loess and Quaternary geology Institute of Earth Environment Chinese Academy of Sciences Xi’an China Institute of geology and geophysics Chinese Academy of Sciences Beijing China Qinghai Institute of Salt Lakes Chinese Academy of Sciences Xining China department of Geography Qinghai Normal University Xining China

A typical sequence of fluvial terraces and aeolian deposits overlying these ter- races were multidisciplinary investigated. New evidences for uplift process of the northeastern Qinghai-Tibetan Plateau in the past 14.million years were obtained. At least 11 river terraces along Huangshui, the first-class tributary of Yellow River, at the Xining-Huzhu region are identi- fied. While the first one (T1) is classified as an accumulation terrace, the others are all basement river terraces, which consist of the Tertiary sandstone and siltstone bedrock, fluvial gravel and pebbles and the overlying aeolian loess-Red Clay deposit. Samples from the aeolian deposits were examined for paleomagnetic stratigraphic reconstruction (1030 samples), luminescence dating (16 samples), magnetic susceptibility and grain-size distribution (more than 4.00 sam- ples). The luminescence dating and stratigraphic correlation suggest that terraces of Tll, T10, T8, T7, T3, T2, T1 were formed at 14. 11.3, 1.55, 1.2, 0.15, 0.07 and 0.01 million years ago, re- spectively. Sedimentological analysis and geomorphological observation indicate that formation and evolution of these terraces were mainly driven by tectonic uplift. Therefore, the terrace se- quence provides an ideal geological record, of the uplift process of the northeastern during the past 14.million years, and the timings of the terraces formation are regarded as the timings of tectonic uplift. The significant uplifting events took place at 14. 11.3, 1.2 and 0.15 mil- lion years ago, respectively. The fluvial incision at the Xining-Huzhu region is less than 100 m during a period of ~12 million years in the Miocene era (between the Tll and T9), while the Huangshui River had incised 4.2 m during the past 1.2 million years (from T7 to the present floodplain). The river incision process clearly demonstrates that accelerated rising of the north- eastern Qinghai-Tibet Plateau during the late Cenozoic, and provides new evidence of previous thoughts

关键词： river terrace, tectonic uplift, loess-Red Clay, the past 14 million years, northeastern Qinghai-Tibet Plateau.

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Interactions between hotspots and the Southwest Indian Ridge during the last 90 Ma:Implications on the formation of oceanic plateaus and intra-plate seamounts

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Science China Earth Sciences 2011年第8期54卷 1177-1188页

作者： ZHANG Tao 1,2,3,4.LIN Jian 5 & GAO JinYao 3,4.1 Institute of Geodesy and geophysics,Chinese Academy of Sciences,Wuhan 4.0077,China 2 Graduate University of Chinese Academy of Sciences,Beijing 10004.,China 3 The Second Institute of Oceanography,State Oceanic Administrator,Hangzhou 310012,China 4.Key Laboratory of Submarine Geosciences,State Oceanic Administrator,Hangzhou 310012,China 5 department of geology and geophysics,Woods Hole Oceanographic Institution,Woods Hole,MA 0254.,{4. Institute of Geodesy and geophysics Chinese Academy of Sciences Wuhan China Graduate University of Chinese Academy of Sciences Beijing China The Second Institute of Oceanography State Oceanic Administrator Hangzhou China Key Laboratory of Submarine Geosciences State Oceanic Administrator Hangzhou China

This study investigates the relationship between the hotspot-ridge interaction and the formation of oceanic plateaus and seamounts in the Southwest Indian *** first calculated the relative distance between the Southwest Indian Ridge (SWIR) and relevant hotspots on the basis of models of plate reconstruction,and then calculated the corresponding excess magmatic anomalies of the hotspots on the basis of residual bathymetry and Airy *** results reveal that the activities of the Marion hotspot can be divided into three main phases:interaction with the paleo-Rodrigues triple junction (73.6-68.5 Ma),interaction with the SWIR (68.5-4..7 Ma),and intra-plate volcanism (4..7-0 Ma).These three phases correspond to the formation of the eastern,central,and western parts of the Del Cano Rise,*** magnitude and apparent periodicity of the magmatic volume flux of the Marion hotspot appear to be dominated by the hotspot-ridge *** periodicity of the Marion hotspot is about 25 Ma,which is much longer than that of the Hawaii and Iceland hotspots (about 15 Ma).

关键词： Southwest Indian Ocean hotspot-ridge interaction magmatic volume flux oceanic plateaus seamounts

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Paleotemperature changes over the past 3000 years in eastern Beijing, China: A reconstraction based on Mg/Sr records in a stalagmite

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Chinese Science Bulletin 2003年第4期48卷 395-400页

作者： MA Zhibang1, LI Hongchun2, XIA Ming1, KU Tehlung2, PENG Zicheng3, CHEN Yushu4.& ZHANG Zhaofeng3 1. Institute of geology and geophysics, Chinese Academy of Sciences, Beijing 100029, China 2. department of Earth Sciences, University of Southern California, Los Angeles, CA90089-074., usa 3. department of Earth and Space Science, University of Science and Technology of China, Hefei 230026, China 4. Beijing Foshan Tourist Service Centre, Beijing 101201, China Institute of geology and geophysics Chinese Academy of Sciences Beijing 100029 China department of Earth Sciences University of Southern California Los Angeles CA 90089-0740 United States department of Earth and Space Science University of Science and Technology of China Hefei 230026 China Beijing Foshan Tourist Service Centre Beijing 101201 China

The Mg/Sr ratio in a stalagmite, which is di-rectly proportional to DMg/Ca, the solid-liquid distribution coefficient of Mg, is proposed as a geochemical thermometer to estimate paleotemperature changes. The paleotempera-ture change in eastern Beijing over the past 3000 years has been reconstructed by using this thermometer in the stalag-mite ZFFS-1 from Jingdong Cave. The records can be di-vided into two periods: 3000—2000 aBP, cool and wet, the air temperature averaging 9.8℃; and 2000 aBP—present, hot and dry, the air temperature being 1℃ higher than the mean value (11.7℃) of the past 3000 years. During 500—200 aBP, the air temperature was about 1.2℃ lower than that of the present, corresponding to the Little Ice Age in Europe. Like d 18O and d 13C, Mg/Sr (or DMg/Ca) reflects an obviously warming trend of the past 200 years. These results are sup-ported by historic records.

关键词：北京京东溶洞石笋 Mg/Sr记录古气温测年 3000年

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Origin of the Red Earth sequence on the northeastern Tibetan Plateau and its implications for regional aridity since the middle Miocene

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Science China Earth Sciences 2006年第5期49卷 505-517页

作者： WANG Xianyan1,7, LU Huayu1,2, JI Junfeg3, WANG Xiaoyong1,7, ZHAO Jingbo4. HUANG Baochun5 & LI Zhen6 1. SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710075, China 2. department of Urban and Resources Sciences, Nanjing University, Nanjing 210093, China 3. department of Earth Sciences, Nanjing University, Nanjing 210093, China 4. department of Geography, Shaanxi Normal University, Xi’an 710062, China 5. Institute of geology and {4., Chinese Academy of Sciences, Beijing 100029, China 6 department of Geography, Qinghai Normal University, Xining 810008, China 7. Graduate School of the Chinese Academy of Sciences, Beijing 100039, China SKLLQG Institute of Earth Environment Chinese Academy of Sciences Xi’an China Graduate School of the Chinese Academy of Sciences Beijing China department of Urban and Resources Sciences Nanjing University Nanjing China department of Earth Sciences Nanjing University Nanjing China department of Geography Shaanxi Normal University Xi’an China Institute of geology and geophysics Chinese Academy of Sciences Beijing China department of Geography Qinghai Normal University Xining China

The Red Earth deposit around Xining, northeastern Tibetan Plateau, has beenstudied in terms of soil micro-structure, grain-size distribution, major- and trace-elementchemistry and magne-tostratigraphy. Field investigations indicate that the Red Earth sequenceconsists of 25 visually definable yellow-brown and weakly-developed soils interbedded with reddishstrongly-developed soils, and has a similar structure to the aeolian Red Clay deposit on the ChineseLoess Plateau. Grain-size analysis shows that the Red Earth deposit is very fine-grained with anegligible sand fraction ( > 63 μm). Thin-section observations under light microscopy show that thedeposit has a clayey texture and the coarse fraction ( > 10 μm) mainly consists of quartz,feldspar and micas. Pyroxene and hornblende were also observed. This mineralogical composition ofthe coarse fraction is similar to that of the Quaternary loess. In addition, all of the mineralgrains are semi angular semi-angular and are generally finer than 63 μm. There is a good agreementbetween the major and minor trace element chemistry of loess-soil units and the Red Earth *** REE distributions of the loess-soil and the Red Earth deposit are similar in shape, withenriched LREE and fairly flat HREE profiles and a clear negative Eu anomaly. The geochemicalcharacteristics of the Red Earth deposit are also identical to those of upper continental crust,thus indicating a wind-blown origin. Magnetostratigraphic investigation shows that onset of the RedEarth deposition predates 11.4.Ma BP (13.6 Ma at a nearby site). The distribution of the reportedMiocene aeolian loess at Qin''an of the Loess Plateau is still unknown. Our results indicate thatthis aeolian deposit had extended to the northeastern Tibetan Plateau by at least the middleMiocene. The similarity of the element geochemistry between the Red Earth deposit and the overlyingloess shows that they may have similar sources and dynamic transport system, and may indicate thatthe

关键词： Red Earth deposit, Northeastern Tibetan Plateau, aeolian deposit, aridity of Asia, the middle Miocene.

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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, Minnesota University, Mineapolis mn 55455, {4. College of Geography Science Nanjing Normal University Nanjing China department of geology and geophysics Minnesota University Mineapolis USA

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.

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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, University of Minnesota, mn {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 300 MPa and temperature of 1373 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

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Tectonic evolution of the Dabieshan orogen: In the view from polyphase deformation of the Beihuaiyang metamorphic zone

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Science China Earth Sciences 2005年第7期48卷 886-899页

作者： LIN Wei1, 2, Faure Michel3, WANG Qingchen1 & Arnaud Nicolas4.1. LTE, Institute of geology and geophysics, Chinese Academy of Sciences, Beijing 100029, China 2. department of Earth and Planetary Sciences, Graduate School of Science, Nagoya University, Japan 3. ISTO, UMR CNRS 6113, Batiment Géosciences, Orléans Université d’Orléans, 4.067 Orléans Cedex 2, France 4. UMR 6524."Magmas et Volcans", 5 Rue Kessler, 63000 Clermont-Ferrand, France LTE Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China department of Earth and Planetary Sciences Graduate School of Science Nagoya University Japan ISTO UMR CNRS 6113 Orléans Université d'Orléans 45067 Orléans Cedex 2 France UMR 6524.Magmas et Volcans 63000 Clermont-Ferrand 5 Rue Kessler France

The Beihuaiyang metamorphic zone was formed by the Early Mesozoic collision of the North and South China Blocks. It consisted of the Foziling and Luzhenguan complexes and was thought to have never afforded a deep subduction. A similar feature of the deformation in the Dabieshan UHP metamorphic rocks implies that these different tectonic units share the same geodynamic background. The early stage of deformation can be preserved on account of their relatively shallower subduction than that for UHP rocks. On the basis of an analysis of the geo- logical structure and geochronological results, five deformational stages have been recognized: a D1-Early compressional deformation which represents the continental subduction; a D2-Early exhumation deformation producing a syn-convergence exhumation; a D3-Main deformation, represented by an exhumation deformation with Late Triassic age; a D4.Doming and its margin extensional gravity collapse deformation and finally a D5-regional extensional deformation of Cretaceous that was mostly introduced by the migmatization and plutonism.

关键词： Beihuaiyang metamorphic zone geometry kinematic polyphase deformation tectonic evolution.

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