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Ancient Changjiang channel system in the East china Sea continental shelf during the last glaciation

Science china Earth Sciences 2005年第11期48卷 1972-1978页

作者： LI Guangxue1,2. LIU Yong1, YANG Zigeng3, YUE Shuhong4, YANG Wenda5 & HAN Xibin1 1. College of marine Geo-science, Ocean University of china, {2. 2.6003, china 2. Shandong Key Laboratory of Sea Floor Resource and Exploration Technique, {2. 2.6003, china 3. {2. Institute of marine geology, qingdao 2.6071, china 4. College of marine Environment, Ocean University of china, {2. 2.6003, china 5. First survey Team of marine geology, Shanghai Bureau of Petroleum, Shanghai 2.12.8, china 1. College of marine Geo-science Ocean University of China 266003 Qingdao China 2. Shandong Key Laboratory of Sea Floor Resource and Exploration Technique 266003 Qingdao China 3. qingdao Institute of marine {2. 266071 Qingdao China 4. College of marine Environment Ocean University of China 266003 Qingdao China 5. First survey Team of marine {2. Shanghai Bureau of Petroleum 201208 Shanghai China

Based on the data of high-resolution seismic profiles, an ancient river channel sys-tem of the last glaciation occurred along the Zhedong and Xihu depression in the southeast of Hupijiao rise. The distribution of the channel fill system shows that the ancient Changjiang River went through the Changjiang depression into the low land plain of the outside continental shelf during the low sea level cycle of the last glaciation. The big channel fill into Okinawa Trough is not found due to the depletion of the river kinetic energy in the low land plain. The river discharge dispersal was of an important role to the dilution of the northern Okinawa Trough sea at that time. Six ancient river channel systems (A―F), which are main distributaries of ancient Changjiang in the East china Sea continental shelf during the last glaciation, may be buried off the modern Changjiang estuary. The distribution of these channels coincides with the zonal elevations in the sea floor.

关键词： last glaciation, continental shelf plain, Changjiang River, ancient channel fill

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Enrichment mechanisms of rare earth elements in marine hydrogenic ferromanganese crusts

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Science china Earth Sciences 2011年第2期54卷 197-203页

作者： JIANG XueJun1,2.LIN XueHui1,2.YAO De3,4 & GUO WeiDong5 1 Key Laboratory of marine Oil and Gas Resources and marine Environment,Ministry of Land and Resources,{2.,china 2.qingdao Institute of marine geology,china geological survey,{2.,china 3 Institute of Resources and Environment,Shandong University of Technology,Zibo 2.5049,china 4 Institute of Oceanology,Chinese Academy of Sciences,{2.,china 5 Department of Oceanography,Xiamen University,Xiamen 361005,china 1. Key Laboratory of marine Oil and Gas Resources and marine Environment Ministry of Land and Resources Qingdao 266071 China2. Qingdao Institute of Marine Geology China Geological Survey Qingdao 266071 China3. Institute of Resources and Environment Shandong University of Technology Zibo 255049 China4. Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China5. Department of Oceanography Xiamen University Xiamen 361005 China

A series of selective extraction experiments were conducted on marine hydrogenic ferromanganese crusts from the seamount near the Line Island to investigate the distribution of rare earth elements （REEs） and the mechanisms of combination between REEs and the hydrogenic ferromanganese crusts. The enrichment of REEs in hydrogenic ferromanganese crusts is attributed mainly to the mineral or oxide/hydroxide of the crust rather than the growth environment. The REEs are present mainly in amorphous ferric oxide/hydroxide rather than in 6-MnO2. Amorphous ferric oxide/hydroxide preferentially combines free REE3＋, while 6-MnO2.combines the REE-carbonate complexes in modern seawater. The REEs in seawater are combined more strongly with amorphous ferric oxide/hydroxides than with 6-MnO2. The positive Ce anomaly in hydrogenic ferromanganese crusts results from the oxidation of soluble Ce3＋ to insoluble Ce4＋ by the actively soluble oxygen of the bottom current rather than by the oxidation of δ-MnO2.

关键词： rare earth elements hydrogenic ferromanganese crust selective extraction experiment geochemistry combinationmechanism

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REE and Sr-Nd isotope characteristics of hydrothermal chimney at Jade area in the Okinawa Trough

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Acta Oceanologica Sinica 2004年第2期23卷 287-296页

作者： LIUYanguang MENGXianwei FUYunxia KeyLaboratoryofmarineSedimentologyandEnvironmentgeologyofStateOceanicAdministration Qingdao266061China geologicalResourceandGeotechnicalEngineeringCooperationofqingdao Qingdao266071China

Hydrothermal chimney is a product of hydrothermal activity on the seabed. Chimney samples dredged from Jade hydrothermal area in Izena depression of the Okinawa Trough, are characterized by relatively enriched light rare earth elements (LREE) and strongly positive Eu anomalies. 87Sr/86Sr and 143Nd/144Nd of these samples are exactly between those of seawater and of acidic pumice, averaged at 0.70892. and 0.512.92. respectively. These characteristics imply that the main source of hydrothermal sulfide at Jade area is possibly the undersurface acidic rocks. The mineralizing mechanism can be summarized as follows: Large amount of mineralized material would be leached out and LREE-enriched hydrothermal solution would be subsequently produced as a result of thermo-chemical exchange reaction between acidic volcanic rocks and heated seawater that penetrated in advance from upper water mass. The spurting out from the seabed and quickly crystallizing in the seawater of hydrothermal solution are responsible for the formation of Cu-Zn sulfide and barite-amorphous SiO2.minerals that are characterized by enriched LREE and positively strong Eu anomalies.

关键词： hydrothermal chimney rare earth elements Sr and Nd isotopes

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Morphology and internal architecture of a banner bank off Chengshan Headland, Shandong Peninsula

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Acta Oceanologica Sinica 2009年第5期28卷 58-65页

作者： ZHOU Liangyong LIU Jia XUE Chunting KONG Xianghuai BAI Dapeng College of marine Geo-science Ocean University of China Qingdao 266003 China The Key Laboratory of marine Hydrocarbon Resources and Environmental geology Ministry of Land and Resources Qingdao 266071 China qingdao Institute of marine {2. Qingdao 266071 China

A banner bank off the north coast of the Chengshan Headland, Shandong Peninsula, has been described on the basis of echo sounder bathymetry, side-scan sonar and high-resolution seismic data sets. The bank is in NWW direction, approximately parallel to the coastline. The bank consists of sandy silt or clayed silt. Sand waves and megaripples are observed on the north side, which result from strong tidal currents around the headland and storm waves in winter. These bed forms indicate that the bank is influenced by the modern hydrodynamics. The bank is separated from the coast and Holocene subaqueous clinoform around the Shandong Peninsula in its east part. High-resolution seismic profiles reveal that the bank was formed during two periods： the earlier seismic unit Ua, and later seismic units Ub and Uc which overlays Ua with erosional surfaces on its south side and north side, respectively. As comparing with the clinoform, the bank has a different internal architecture. In the west of the bank, however, topography and surface sediment characteristics suggest that the bank links to the clinoform. The authors propose that seismic Ua is a residual part of early clinoform deposit. After the sediments in the north and south of Ua were eroded by strong currents, the Ub and Uc started to deposit probably by a complex hydrodynamic process. These results provide new insights into the evolution of the bank and its relation with the Holocene subqueous clinoform.

关键词： banner bank morphology internal architecture bed forms Holocene subqueous clinoform Huanghai Sea

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Carbon isotope composition of the Lower Triassic marine carbonates, Lower Yangtze Region, South china

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Science china Earth Sciences 2006年第3期49卷 225-241页

作者： ZUO Jingxun1,2. TONG Jinnan3, QIU Haiou4 & ZHAO Laishi3 1. Nanjing Institute of geology and Palaeontology, Chinese Academy of Sciences, Nanjing 2.0008, china 2. Henan Institute of {2. survey, Zhengzhou 450007, china 3. State Key Laboratory of {2. Processes and Mineral Resources at china University of Geosciences, Wuhan 430074, china 4. Faculty of Material Sciences and Chemical Engineering, china University of Geosciences, Wuhan 430074, china 1. Nanjing Institute of geology and Palaeontology Chinese Academy of Sciences Nanjing 210008 China 2. Henan Institute of geological survey Zhengzhou 450007 China 3. State Key Laboratory of geological Processes and Mineral Resources at china University of Geosciences Wuhan 430074 China 4. Faculty of Material Sciences and Chemical Engineering China University of Geosciences Wuhan 430074 China

Studies on three Lower Triassic sections located on the shallow water platform, the deep water slope and in the deep water basin in the Lower Yangtze Region, South china, show the similar trend of carbon isotope evolution. Biostratigraphic correlations among the Lower Triassic sections on the basis of standard conodont zones indicate that three negative shifts occurred in the Griesbachian, the Smithian and the late Spathian stages respectively, and one distinctly positive shift occurred in the early Spathian stage. Trend of carbon isotope evolution of the Lower Triassic reflects some significant changes in the global carbon cycle. Moreover, δ 13C background values are intensively controlled by palaeogeographic environment. In general, δ 13C values from deep-water slope carbonates are lighter than those from carbonate platform and heavier than those from deep-water basin carbonates. The positive carbon isotope excursion may be induced by a significant amount of organic carbon burial in marine sediments and increase in primary productivity. The large negative carbon isotope excursions during the Early Triassic in Lower Yangtze Region are interpreted to relate to volcano eruptions based on tuffaceous claystone interlayers observed near the Permian-Triassic boundary, the Induan- Olenekian boundary and the Lower Triassic-Middle Triassic boundary.

关键词： Lower Triassic, carbon isotope compositions, palaeogeography, volcanic eruptions, Lower Yangtze Region.

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geological Evidence for the Presence of the Emperor Event in china

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Acta Geologica Sinica(English Edition) 1993年第2期67卷 235-244页

作者： Ge Tongming, Fan Limin and Liu Jian Guangzhou marine geological {2., Ministry of geology and Mineral Resources of china, Guangzhou Guangzhou marine geological {2. Ministry of Geology and Mineral Resources of China Guangzhou

The presence of the reversals of the geomagnetic field within the Brunhes is indicated by paleomagnetic stuides on Cenozoic volcanic rocks in the Leizhou Peninsula, loess strata and Quaternary marine sediments in the Pearl River Mouth basin in china. These regional reversals occured at 0.58±0.13 Ma, 0.45 Ma and 0.47—0.48 Ma respectively according to the results of K-Ar isotopic dating and climatostratigraphic and biostratigraphic analyses. The reversals equivalent to the Emperor Event is suggested.The reversals revealed in different regions with various lithologic characters in china prove that the Emperor Event is a global reversal event rather than a geomagnetic excursion, and its confirmation will permit a precise definition of the Middle/Late Pleistocene boundary.

关键词： Brunhes polarity reversal Emperor Event

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Glacial atmospheric CO_(2. decline in association with decrease of marine sedimentary phosphorus

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Science china Earth Sciences 2006年第3期49卷 322-330页

作者： WENG Huanxin1, ZHANG Xingmao1, WU Nengyou2. WANG Ying1, CHEN Lihong1, ZHONG Hexian2.& QIN Yachao1 1. Institute of Environment & Biogeochemistry, Zhejiang University, Hangzhou 31002., china 2. Guangzhou marine {2. survey, CGS, MLR, Guangzhou 510760, china 1. Institute of Environment & Biogeochemistry Zhejiang University Hangzhou 310027 China 2. Guangzhou marine geological {2. CGS MLR Guangzhou 510760 China

The environmental and biogeochemical information extracted from the sediments col- lected from the northern shelf of the South china Sea shows that terrigenous inputs of phosphorus into the sea remained relatively constant, and the variation of phosphorus contents at different depths was caused by climatic and environmental changes. The findings also suggest that the vertical varia- tion of phosphorus content was opposite to those of calcium carbonate and cadmium, and the func- tional correlation between CO2.and PO43? in seawater was given by calculating the chemical equilib- rium, indicating that the accumulation of marine sedimentary phosphorus may have something to do with the variation of atmospheric CO2. The decreased phosphorus accumulation as well as the cor- respondingly-increased calcium carbonate content might be one of key factors causing glacial at- mospheric CO2.decline.

关键词： sedimentary phosphorus, calcium carbonate, atmospheric CO2. northern shelf of the South china Sea, biogeochemistry.

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Influence of permeability on hydrothermal circulation in the sediment-buried oceanic crust

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Science china Earth Sciences 2006年第7期49卷 773-784页

作者： WANG Xingtao1,2. ZHAI Shikui1, MENG Fanshun1, LI Huaiming1, YU Zenghui1, SUN Ge1 & XUE Gang1 1 marine Geoscience Institute, Ocean University of china, {2. 2.6003, china 2.Bureau of Ocean and Fishery, Weihai 2.42.0, china 1. marine Geoscience Institute Ocean University of China Qingdao 266003 China 2. Bureau of Ocean and Fishery Weihai 264200 China

Hydrothermal convection in the upper oceanic crust has been inferred to be a common and important process. Under the simplified conditions of planar boundaries, permeability provides a strong constraint on the pattern of circulation, the dimensions of convective cells and flow field of hydrothermal circulation. By applying an advanced numerical modeling method, to our knowledge, it is the first time to investigate convection as it is influenced by different strata permeability structures, formational anisotropy, fracture zone and cooling intrusion. The simplified geological model is com-posed of 3 layers, sedimentary layer, high permeable basement layer and low permeable basement layer from top to bottom. When permeability in high permeable layer is 10 times larger than that in sedimentary layer, convection occurs in high permeable layer. The pattern of hydrothermal circulation and flow velocity of hydrothermal fluid are strongly influenced by strata permeability structures, changes of permeability in high permeable basement layer, fracture zone and cooling intrusion. However, formational anisotropy relatively exerts weak influence on hydrothermal circulation, with the ratio up to 1.5 of vertical permeability to lateral permeability in high permeable layer. Fracture zone existing in basement is the most important factor affecting the circulation field. The effects of a local intrusion are limited to convection intensity above the intrusion and have little impact on the fluid flow on a regional scale. As the result of numerical modelling, key factors affecting the hydrothermal cir-culation are good permeable zone and long-term heat source, not including fluid source.

关键词： hydrothermal circulation, permeability, oceanic crust, numerical model.

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Quaternary marine transgressions in eastern china

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Journal of Palaeogeography 2012年第2期1卷 105-125页

作者： Lin Jingxing1, 3, Dai Luping2. 3 1. Institute of geology, Chinese Academy of geological Sciences, Beijing 100037, {2. 2. Key Laboratory of marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, qingdao 2.6071, {2. 3. College of Earth Science, Graduate University of Chinese Academy of Sciences, Beijing 100049, {2. Institute of geology Chinese Academy of Geological Sciences Beijing 100037 China College of Earth Science Graduate University of Chinese Academy of Sciences Beijing 100049 China Key Laboratory of marine Ecology and Environmental Sciences Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China

Based on the data from 117 holes (9151 samples) and the research on ecology and palaeoecology of Foraminifera combined with that on Ostracoda, diatoms, pollen and spores, eight marine transgressions have been recognized in the great plain regions through the Quaternary sequences and two marine transgressions have been found since the Late Pleistocene in the coastal plain (bedrock coast) areas. In the North {2. Plain, these are in ascending order:the Bohai transgression in the Early Pleistocene, the Haixing and Huanghua transgressions in the Middle Pleistocene, the Baiyangdian and Cangzhou transgressions in the Late Pleistocene, and the Tianjin transgression in the Holocene. In the Yangtze River Delta region the Rugao and Zhoupu transgressions occurred in the Early Pleistocene, the Shanghai, Jiading, and Wangdian transgressions in the Middle Pleistocene, the Jiangyin and Ge Hu transgressions in the Late Pleistocene, and the Zhenjiang transgression in the Holocene. In the coastal plain (bedrock coast) areas of North {2., the Cangzhou transgression was recorded in the Late Pleistocene and the Tianjin transgression in the Holocene, whereas in South {2. the Fuzhou transgression took place in the Late Pleistocene and the Changle transgression in the Holocene. The transgressions correspond to warm periods and regressions to cold periods. The younger transgressions were not only of shorter duration, but also of larger magnitude. These findings point to the existence of four flood event strata since the Middle Pleistocene: two in the late Middle Pleistocene and another two in the Late Pleistocene.

关键词： Quaternary marine transgressions palaeoclimate eastern china

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Middle and Late Tertiary Palaeogeography and Palaeoenvironment on the Northern Continental Margin of the South china Sea

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Acta Geologica Sinica(English Edition) 1990年第2期64卷 211-222页

作者： Duan Weiwu Huang Yongyang Guangzhou marine geological {2., Ministry of geology and Mineral Resources, Guangzhou, Guangdong Chinese Academy of geological Sciences Beijing

Based essentially on research results of calcareous nannofossils, combined with some other microfossil da-ta and several secondary depositional breaks, this paper discusses the criteria of division and comparison of themiddle and late Tertiary marine sediments, palaeogeographical and palaeoenvironmental evolution andpalaeoclimates on the northern continental margin of the South china Sea, comprising the Tainan basin, PearlRiver Mouth basin. Southeast Hainan basin and Beibu Gulf basin. Study shows that the upper Oligocene toPliocene strata in the whole area consist essentially of marine sediments except in the Beibu Gulf basin. Theyinclude littoral. neritic and deltaic sediments as well as carbonate rock-bioherm limestone. The sea advancedfrom southeast to northwest. During the transgression there appeared three culminations coinciding to thestages of deposition of nannofossil zones NN4-5, NN11 and 13-15.

关键词： Middle and Late Tertiary Palaeogeography and Palaeoenvironment on the Northern Continental Margin of the South china Sea

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