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Sporopollen analysis of Core B10 in the southern Yellow Sea and the reflected characteristics of climate changes

chinese Science Bulletin 2003年第B06期48卷 42-48页

作者： FU Mingzuo~(1,2.3., LI Zhen~1, XU Xiaowei~1 & SHl Xuefa~1 1. key laboratory of Marine Sedimentology and Environmental {2., First institute of Oceanography. State Oceanic Administration, Qingdao 2.6061. china 2. institute of Oceanology, chinese Academy of sciences, Qingdao 2.6071. china 3. Graduate School, chinese Academy of sciences, Beijing 10003.. china 1. key laboratory of Marine Sedimentology and Environmental {2. First institute of Oceanography State Oceanic Administration 266061 Qingdao China 2. institute of Oceanology Chinese Academy of Sciences 266071 Qingdao China 3. Graduate School Chinese Academy of Sciences 100039 Beijing China

Eight sporopollen zones have been divided based on the results of high-resolution sporopollen analysis of Core B10 in the southern Yellow Sea. Based on the results along with ^14C datings and the subbottom profiling data,climatic and environmental changes since the last stage of late Pleistocene are discussed. The main conclusions are drawn as follows: (1) the vegetation evolved in the process of coniferous forest-grassland containing broad-leaved trees→coniferous and broad-leaved mixed forest→coniferons and broad-leaved mixed forest-grassland prevailed by coniferous trees→coniferous and broad-leaved mixed forest-grassland containing evergreen broad-leaved trees→coniferons and broad-leaved mixed forest-grassland prevailed by broadleaved trees→deciduous broad-leaved forest-meadow containing evergreen broad-leaved trees→coniferous and broadleaved mixed forest-grassland prevailed by broad-leaved trees→coniferous and broad-leaved mixed forest containing evergreen broad-leaved trees; (2. eight stages of climate changes are identified as the cold and dry stage, the temperate and wet stage, the cold and dry stage, the warm and dry stage, the temperate and wet stage, the hot and dry stage, the temperate and dry stage, then the warm and dry stage in turn; (3. the sedimentary environment developed from land,to littoral zone, to land again, then to shore-neritic zone; and (4) the Yellow Sea Warm Current formed during early-Holocene rather than Atlantic stage.

关键词：中国黄海气候变化碳14年代测定底基压型数据更新世沉积环境大西洋

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Temperature variations recovered from tree-rings in the middle Qilian Mountain over the last millennium

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Science china Earth sciences 2005年第4期48卷 521-529页

作者： LIU Xiaohong1,2. QIN Dahe1, SHAO Xuemei , CHEN Tuo1 & REN Jiawen12.1. Cold and Arid Regions Environmental and Engineering Research institute, {2. Academy of sciences, Lanzhou 73.000, china 2. institute of Geographical sciences and Natural resources Research, {2. Academy of sciences, Beijing 100101, china 1. Cold and Arid Regions Environmental and Engineering Research institute Chinese Academy of Sciences 730000 Lanzhou China 2. institute of Geographical sciences and Natural {2. Research Chinese Academy of Sciences 100101 Beijing China

Based on the cross-dated tree-ring samples collected from the middle Qilian Moun- tain, a standard ring-width chronology had been developed, which covered the period AD 1000 to 2.00. The correlations between the chronology and climatic records from the nearby meteorological stations indicated that temperature was the dominant climatic factor for tree growth at upper timberline, and the most important climatic factor for the tree growth in the area was the mean temperature from previous December to current April. The temperature variations recovered from the ring-width data showed a cold period during the “Little Ice Age” and the con- tinuous warming during the twentieth century. Comparison between the ring-width chronology and δ18O records from the Dunde ice core in the Qilian Mountain indicated that there was a con- sistent trend in both time series. A significant correlation existed between our ring-width chro- nology and the Northern Hemispheric temperature, suggesting that the climate changes in the Qilian Mountain were not only driven by regional factors, but also responsive to the global cli- mate.

关键词： middle Qilian Mountain, tree-ring width chronology, temperature variations.

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Gymnosperms on the eve of the terminal Permian mass extinction in North china and their survival strategies

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chinese Science Bulletin 1998年第11期43卷 889-897页

作者： WANG Ziqiang+1 and ZHANG Zhiping+2. 1. Tianjin institute of geology and {2. resources, chinese Academy of Geological sciences, Tianjin 3.0170, china 2. Tianjin Centre of Physical and Chemical Techniques, Tianjin 3.0050, china Tianjin institute of geology and {2. {3. Chinese Academy of Geological Sciences Tianjin China Tianjin Centre of Phyhical and Chemical Techniques Tianjin China

Main characteristics of the Permian redbed gymnosperms in North china have been summarized: dominant peltasperms and conifers, numerous enigmatics such as Gigantonoclea and Psygmophyllum, and abundant precursors of Mesozoic gymnosperms. Furthermore, stresses affecting these plants survival are suggested to be paleoatmospheric CO-2.concentration, water stress, wind and fire activities, and fungal infection. Consequently, a preliminary analysis accounts for the ecological strategies of these gymnosperms to the P-Tr event.

关键词： North china Permian gymnosperms mass extinction.

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Crustal structure of Gondwana-and Yangtze-typed blocks:An example by wide-angle seismic profile from Menglian to Malong in western Yunnan

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Science china Earth sciences 2005年第11期48卷 1828-1836页

作者： ZHANG Zhongjie1, BAI Zhiming1, WANG Chunyong2. TENG Jiwen1, Lü Qingtian3. LI Jiliang1, SUN Shanxue1 & WANG Xinzheng1 1. institute of geology and Geophysics, {2. Academy of sciences, Beijing 10002., china 2. institute of Geophysics, {2. Seismological Bureau, Beijing 100081, china 3. institute of Deposition Resource, {2. Academy of Geological sciences, Beijing 10003., china 1. institute of geology and Geophysics Chinese Academy of Sciences 100029 Beijing China 2. institute of Geophysics Chinese Seismological Bureau 100081 Beijing China 3. institute of Deposition Resource Chinese Academy of Geological Sciences 100037 Beijing China

The wide-angle seismic profile between Menglian and Malong crosses the Baoshan block (Gondwana-typed), and Simao and southwestern Yangtze blocks (Yangtze-typed). By in-terpreting the wide-angle seismic data, we obtained the seismic crust/upper mantle structure of P-wave velocities together with the seismic reflections of these three blocks, Changning- Menglian and Mojiang suture zones among the mentioned three blocks. Our interpreting results demonstrate that the P-wave crustal velocity of Simao block is slower than that of Baoshan and southwestern Yangtze block and the crustal thickness gradually thickens from the Baoshan block, Simao to southwestern Yangtze block. Crustal reflection patterns of these three blocks have dis-tinct differences too. For the Gondwana-typed blocks, seismic reflections in the upper crust are well developed while in middle-lower crust they are very weak. The crustal reflections in the Yangtze block are very well developed. The crustal reflection patterns in Simao and southwest-ern Yangtze blocks are distinguishable. The average thickness of the crust in the studied area is about 40 km. And we make some discussions on the crustal thickening model of the three blocks in western Yunnan and tectonic setting of seismic developing and interaction of Gondwana and Yangtze blocks.

关键词： Gondwana blocks,Yangtze blocks,wide-angle profile,crustal structure,tectonic setting

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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, institute of Geochemistry, {2. Academy of sciences, Guiyang 550002. china 2. Department of geology, china University of Geosciences, Beijing 100083. china 3. Department of geology, Peking University, Beijing 100871, china 1. laboratory of Material in the Earth’s Interior Institute of Geochemistry Chinese Academy of Sciences 550002 Guiyang China 2. Department of geology 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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Constraints of authigenic carbonates on trace elements (Sr,Mg) of lacustrine ostracod shells in paleoenviron-ment reconstruction and its mechanism

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Science china Earth sciences 2008年第5期51卷 654-664页

作者： HU Guang1,2. JIN ZhangDong1 & ZHANG Fei3.1 State key laboratory of Loess and Quaternary {2., institute of Earth Environment, chinese Academy of sciences, Xi’an 710075, china 2.Graduate University of the chinese Academy of sciences, Beijing 100049, china 3.College of resources and Environmental Science, Nanjing Agricultural University, Nanjing 2.0095, china State key laboratory of Loess and Quaternary {2. Institute of Earth Environment Chinese Academy of Sciences Xi’an 710075 China Graduate University of the chinese Academy of sciences Beijing 100049 China College of resources and Env

Molar ratios of Mg/Ca and Sr/Ca were measured in two species of ostracod shells preserved in the upper core (15–55 m) of the Hequing Basin in Yunnan Province, southwest china. By correlating the molar ratios between Mg/Ca and Sr/Ca and comparing them with Sr concentrations of the sediments, we suggested that: (1) the molar Mg/Ca and Sr/Ca ratio variations in respective ostracod primo reflected the changes in its ambient water composition and ecology; (2. the molar Sr/Ca ratios responded better to the salinity change linearly than Mg/Ca without aragonite precipitation in the system, and otherwise there was no linear relation between them; and (3. the molar Sr/Ca ratios were mainly controlled by salinity and authigenic carbonate precipitation, whereas the molar Mg/Ca ratios were related to both salinity and temperature. In fact, the rate of ostracod growth owing to temperature controls the fluctuation of Mg/Ca in shells. Here, more attentions should be paid to the constraint of authigenic mineral precipitation processes on the trace elements in ostracod shells and to the correlation between these trace elements in biogenic carbonates and compositions of the sediments in systems and in future in vitro experiments.

关键词： ostracod shell molar Sr/Ca ratio molar Mg/Ca ratio environmental response Heqing Basin

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Petrogenesis and dating of the Kangding complex,Sichuan Province

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Science china Earth sciences 2005年第5期48卷 622-634页

作者： CHEN Yuelong 1 , LUO Zhaohua 1 , ZHAO Junxiang, LI Zhihong, ZHANG Hongfei & SONG Biao 3.1. Faculty of Earth sciences and Natural resources,{2. University of Geosciences, Beijing 100083.{2. 2. Faculty of Earth sciences,{2. University of Geosciences, Wuhan 43.074,{2. 3. Beijing SHRIMP Center, institute of geology, chinese Academy of Geological sciences, Beijing 10003.,{2. 1. Faculty of Earth sciences and Natural resources China University of Geosciences 100083 Beijing China 2. Faculty of Earth sciences China University of Geosciences 430074 Wuhan China 3. Beijing SHRIMP Center Institute of Geology Chinese Academy of Geological Sciences 100037 Beijing China

An analysis of major and trace element geochemistry and SHRIMP U-Pb zircon dating of mafic, intermediate, and felsic rocks from the Mianning metamorphic complex of Si- chuan Province was conducted. One of our conclusions is that a majority of the zircons crystal- lized between 72. and 773.Ma in a magmatic regime. The complexes contain early to late Pa- leo-proterozoic relict zircons from ancient continental crust. The oldest age, 2.68 Ma, may rep- resent the basement of the Yangtze block. Overgrowth zircon rims and palingenetic zircons have been observed and dated, and are believed to have formed after crystallization, during Paleozoic and Mesozoic metamorphic-anatexis. We also conclude that depletion of Nb, Ta, HREE, in a spider-diagram normalized to primitive mantle and calc-alkaline association, implies that they formed in island-arc or under-plating settings.

关键词： Kangding complex, zircons, SHRIMP, tectonic setting.

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Distribution of molluscan remains in the sediment of the Chukchi Sea and its vicinity, the Arctic

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Acta Oceanologica Sinica 2003年第4期22卷 607-619页

作者： Gao Aiguo 1,2. Xu Fengshan3. Sun Haiqing 1,2. Li Lon1 1. First institute of Oceanography, State Oceanic Administration, Qingdao 2.6061,china. 2. {2. laboratory of Marine Sedimentology and Environmental geology, State Oceanic Administration, Qingdao 2.6061,china 3. institute of Oceanology, chinese Academy of {13., Qingdao 2.6071,china State Ocean Adm Inst Oceanog 1 Qingdao 266061 Peoples R China State Ocean Adm Key Lab Marine Sedimentol & Environm Geol Qingdao 266061 Peoples R China chinese Acad Sci Inst Oceanol Qingdao 266071 Peoples R China

The result of an analysis of mollusca remains collected from the Chukchi Sea, Beaufort Sea and Bering Sea in the First chinese National Arctic Research Expedition, from July to September, 1999 is presented. Seventeen species of mollusca have been identified, which belong to two classes: Bivalvia and Gastropoda. The compositions of the mollusca are very simple. According to the distribution pattern two groups may be distinguished among molluscan species. The Pan-Arctic and circumboreal group comprises Nuculana pernula, ***, Nucula bellotii, Astarte montagui, Seripes groenlandicus, Macoma calcarea, M. moesta alaskana, Liocyrna fluctuosa, Mya pseudoarenaria and Turritella polaris. Three species, Cyclocardia crebricostata, Trichotrois coronata and Argobuccinum oregonense are components of the Pan-Arctic and Pacific boreal group. With regard to feeding habits, detritus feeders dominate. There are 7 species of detritus feeders, i.e., Nuculana pernula, N. radiata, Nucula bellotii, Macoma calcarea, M. moesta alaskana, Macoma sp. and Trichotropis coronata. Detritus feeders are dominant with regard to the numbers of species as well as to the frequency of occurrence. Macoma calcarea is the most abundant species.

关键词： Chukchi Sea Beaufort Sea Bering Sea molluscan remains

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Petrogenesis of Songshugou dunite body in the Qinling orogenic belt, Central china: Constraints from geochemistry and melt inclusions

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Science china Earth sciences 2005年第8期48卷 1146-1157页

作者： SU Li1,2. SONG Shuguang3.& ZHOU Dingwu1 1. key laboratory of Continental Dynamics of the Ministry of Education, Department of {2., Northwestern University, Xi’an 710069, china 2. The Geological Lab Center, china University of Geosciences (Beijing), Beijing 100083. china 3. key laboratory of Orogenic Belts of the Ministry of Education, Department of {2., Peking University, Beijing 100871, china 1. key laboratory of Continental Dynamics of the Ministry of Education Department of Geology Northwestern University 710069 Xi’an China 2. The Geological Lab Center China University of Geosciences 100083 (Beijing)Beijing China 3. key laboratory of Orogenic Belts of the Ministry of Education Department of Geology Peking University 100871 Beijing China

The Songshugou dunite body, which occupies an area of about 2. km2. is the largest ultramafic massif in the eastern Qinling orogenic belt, Central china. The major compo-nent of this body is dunitic rocks including mylonitic dunite and coarse-grained dunite; they oc-cupy about 95 vol% of the total body. Petrography, {3. composition, major and trace ele-ments and primitive melt inclusions have been investigated in this paper; all revealed that this dunite body is the product of melt-rock interaction by porous percolation flow. In comparison with dunite sills or veins in harzburgite from the basal part of Oman ophiolite, this dunite body is characterized by lower contents of Al2.3. CaO and HREE but higher content of highly incom-patible elements and Zr and Hf. The LREE enriched patterns and primitive mantle normalized spidergrams of trace elements are also different from the Oman dunite. Combining with melt in-clusions observed in olivines, we conclude that this dunite body is the product of large- scale porous percolation flow of high-MgO melts within depleted mantle peridotites. The high-MgO magma, in essence, was most probably produced at the hot head of an upwelling mantle plume. The occurrence of the Songshugou dunite body is closely associated with the activity of mantle super-plume in Neo-Proterozoic era in the Yangtze Craton.

关键词： Songshugou dunite body, geochemistry, melt inclusion, mantle plume, Qinling orogenic belt.

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Grain-size features of a Miocene loess-soil sequence at Qinan: Implications on its origin

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Science china Earth sciences 2006年第7期49卷 731-738页

作者： QIAO Yansong1,3. GUO Zhengtang2.1, HAO Qingzhen1, YIN Qiuzhen1, YUAN Baoyin1 & LIU Tungsheng1 1. institute of geology and Geophysics, {2. Academy of sciences, Beijing 10002., china 2. institute of Earth Environment, {2. Academy of sciences, Xi’an 710075, china 3. institute of Geomechanics, {2. Academy of Geological sciences, Beijing 100081, china 1. institute of geology and Geophysics Chinese Academy of Sciences Beijing 100029 China 3. institute of Geomechanics Chinese Academy of Geological Sciences Beijing 100081 China 2. institute of Earth Environment Chinese Academy of Sciences Xi’an 710075 China

In this study, grain-size of 507 bulk samples from the QA-I Mioceneloess-soil sequence at Qinan were analyzed, and the grain-size features are compared with those oftypical Quaternary loess and soil samples, representative lacustrine and fluvial samples. Theresults indicate that the grain-size distribution pattern of the Miocene loess is essentiallysimilar to that of Quaternary loess, but greatly differs from the lacustrine and fluvial *** layers are regularly coarser than soil layers, indicating cyclical climate changes. Mediangrain-size along the 2.3.1 m sequence varies from 6 to 13.μm and the > 63.μm fraction representsonly 5.3. in maximum, 0.9% in average. Long-term grain-size variations are consistent with the loessaccumulation rate at Qinan and with the eolian mass accumulation rate in the North Pacific. Thesefeatures firmly indicate an eolian origin of the studied sequence, and also reveal a coeval changesbetween the long-term changes of eolian grain-size and continental aridity in the dust sourceregions.

关键词： Qinan, Miocene loess-soil sequence, grain-size, eolian origin.

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