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Relationships between bacterial-algal proliferating and mass extinction in the Late Devonian Frasnian-Famennian transition:Enlightening from carbon isotopes and molecular fossils

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Science china Earth Sciences 2005年第10期48卷 1656-1665页

作者： GONG Yiming1,2, XU Ran1, TANG Zhongdao1, SI Yuanlan3.& LI Baohua4 1. Faculty of Earth Science and State key laboratory of Geological Processes and Mineral Resources, china {3. of Geosciences, Wuhan 43.074, china 2. Institute of Resources & Environments, Henan Polytechnic {3., Jiaozuo 454003. china 3. Department of Computer Science, South-Central {3. for Nationalities, Wuhan 43.074, china 4. laboratory of marine geology, tongji university,{13. china university of Geosciences Henan Polytechnic university South-Central university for Nationalities tongji university

Studies show positive shifts of inorganic and organic carbon isotope values (δ 13.carb and δ 13.kerogen) from +0.43.(‰ V-PDB) to +3.54 (‰ V-PDB) and from ?29.3. (‰ V-PDB) to ?24.14 (‰ V-PDB), respectively, B* (Ba* = Ba/ (Al2O3.X 15%)) values from 0.015 to 0.144, TOC values from 0.02% to 0.21%, V/Cr values from 0.3.to 2.0, Sr/Ba values from 3.20 to 49.50 in the Late Devonian Frasnian Upper rhenana zone to the top linguiformis zone of the Yangdi sec-tion deposited in carbonate slope facies of Guilin, Guangxi, South china, which indicates that biomass, productivity, organic carbon burial and salinity increase and that oxygenation near the boundary between sediments and waters decreases from the Late Devonian Frasnian Upper rhenana zone to the top linguiformis zone. Abundance of molecular fossils increases and normal alkanes, isoprenoid hydrocarbon, terpanes and steranes are dominated from the Late Devonian Frasnian to the bottom of Famennian, which shows that the predecessors of molecular fossils of the Frasnian-Famennian (F-F) transition are dominated by marine phytoplankton, zooplankton and benthic bacteria with no photosynthesis. Therefore, it is considered that the F-F transitional mass extinction with a multistage, selection and global synchronizing was caused by bacte-rial-algal proliferating, continuing deterioration of the shallow marine ecoenvironment of the mid-dle-lower latitudes. A simple cause and effect chain can be expressed as: appearance of seed plants and multi-storied forests → enhanced chemical and biochemical weathering and pe-dogenesis → wide development of soils → increasing riverine nutrient fluxes in epicontinental sea → from superoligotrophic to eutrophic in epicontinental sea → proliferating of marine phyto-plankton and zooplankton → frequent red tide and anoxia → mass extinction of shallow marine organisms in the middle-lower latitudes. It is worth notice that the factor drawdown of atmos-pheric Pco2, climatic cooling and sea level falling c

关键词： mass extinction, bacteria-algae, carbon isotopes, molecular fossils, biodiversity, Late Devonian, Guangxi, South china.

Forcing mechanism of the Pleistocene east Asian monsoon variations in a phase perspective

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Science china Earth Sciences 2005年第10期48卷 1708-1717页

作者： TIAN Jun1,2, WANG Pinxian1, CHENG Xinrong1, WANG Rujian1 & SUN Xiangjun1,3.1. State key laboratory of marine {3., tongji university, shanghai 2.0092. china 2. Institute of {3. and Geophysics, Chinese Academy of Sciences, Beijing 100029, china 3. Institute of Botany, Chinese Academy of Sciences, Beijing 100093. china tongji university Chinese Academy of Sciences

The deep sea records from the ODP Sites 1143.and 1144 in the northern and southern South china Sea (SCS), including foraminiferal δ 18O and δ 13., Opal% and pollen percentage, reveal that the variations of the east Asian monsoon have been closely correlated with the variations of the Earth’s orbital parameters (eccentricity, obliquity and precession) and the global ice volume on orbital scale. All the monsoonal proxies show strong 100 ka, 41 ka and 23.ka cycles. Although G. ruber δ 13. of Site 1143.is coherent with the ETP (ETP= normalized (eccentricity + obliquity-precession) at eccentricity, obliquity and precession bands, most of the coherent relationship focuses on the precession band, and the other monsoonal proxies are coherent with the ETP only at the precession band, which indicate that precession dominates the Pleistocene tropical climate changes. The phase relationship of the monsoonal proxies with the foraminiferal δ 18O implies that the global ice volume changes have played a significant role in modulating the east Asian monsoon climate, at least dominating the winter monsoon. This forcing mechanism of the east Asian monsoon is apparently different from that of the Indian ocean mon-soon. The variations of the east Asian monsoon at the precession band, at least that of the winter monsoon, have been controlled not only by the sensible heating but also by the latent heating of the surface water in the South china Sea.

关键词： South china Sea, ODP, east Asian monsoon, orbital forcing, global ice volume.

Palynological record during the Pleistocene (between 1.05 Ma and 0.3. Ma) from ODP1144, northern South china Sea

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Science china Earth Sciences 2004年第1期47卷 30-36页

作者： HUANG Fei & SUN XiangjunInstitute of geology and Paleontology, Chinese Academy of Sciences, Nanjing 210008, china Institute of Botany, Chinese Academy of Sciences, Beijing 100093. china {3. laboratory of marine geology, Ministry of Education, tongji university, shanghai 2.0092. china Correspondence should be addressed to Huang Fei Institute of geology/Paleontology Chinese Academy of Sciences Nanjing 210008 China Institute of Botany Chinese Academy of Sciences Beijing 100093 China key laboratory of marine {3. Ministry of Education Tongji University Shanghai 200092 China

This paper presents the pollen record from the lower section of ODP1144 (depth 501.3.225.7 m, ca. 1.05-0.3. Ma). Two pollen zones (PA and PB) and eleven pollen subzones are recognized. Within zone PB, the 11 pollen subzones (PB21-11) are defined according to the pine, fern and herb variations, and are equivalent to the marine isotope stages 21-11 (MISs 21-11). The interglacial periods are typified by an increase in pine pollen and fern spores, and a decrease in herbaceous pollen, while the patterning during the glacial periods is just the opposite. During the interglacial periods, pollen assemblages were dominated by pine similar to those of the present day, suggesting that the paleoenvironment of the interglacial periods was similar to that of the present day, whereas the glacial periods are marked by an increase in herbaceous pollen, mainly Gramineae and Cyperaceae, indicating that grassland covered the exposed continental shelf when sea level declined. Increased Artemisia percentages and the highest pine influx during MIS12 may result from a stronger winter monsoon.

关键词： pollen record, Pleistocene, ODP1144, northern South china Sea.

Relationship between magnetic fabric parameters and dynamic characteristics of deposits in different environments

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Chinese Science Bulletin 1998年第22期43卷 1917-1921页

作者： CHEN Qingqiang 1,3., LI Congxian\+1 and CONG Youzi\+2 1. marine geology laboratory,{3., shanghai 2.0092. china 2. First Institute of Oceanography, State Oceanic Administration of china, Qingdao 266003. china 3. Guangzhou Institute of marine geology laboratory Tongji University Shanghai China Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou China First Institute of Oceanography State Oceanic Administration of China Qingdao China

Comparison of magnetic fabric parameters of deposits in different modern sedimentary environments indicates that values of \%P, F\% and \%L\% of eolian deposits are lower obviously than those of hydrogenic ones respectively. On relationship diagrams of magnetic fabric parameters, data points of eolian samples concentrated in limited area near origin of coordinates indicate that dynamic intensity is lower with less variation; while those of hydrogenic ones depart from origin of coordinates suggest higher intensity of sedimentary dynamics. Analyses of dynamic characteristics of different sedimentary environments indicate that values of magnetic fabric parameters of deposits are determined by dynamic types and characteristics of depositional processes. Magnetic fabric analyses of deposits are effective in determination of sedimentary environments.

关键词： magnetic fabric parameters sedimentary environment transporting medium.

Microfossils, carbonate lysocline and compensation depth in surface sediments of the northeastern South china Sea

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Acta Oceanologica Sinica 2003年第4期22卷 597-606页

作者： Chen Ronghua1, Xu Jian2, Meng Yi3. Wang Dongjun1 Liu Chuanlian2, Huang Baoqi2, Zhang Fuyuan1 1. key laboratory of Submarine Geosciences of State Oceanic Administration, Hangzhou 3.0012, {3. 2. laboratory of marine geology, tongji university, shanghai 2.0092. china 3. Institute of Estuarine and Coastal Research, East {3. Normal university, shanghai 200062, {3. key Lab. of Submarine Geosci. State Hangzhou 310012 China laboratory of marine geology Tongji University Shanghai 200092 China Institute of Estuarine/Coastal Res. East China Normal University Shanghai 200062 China

Based on the quantitative analyses of abundance of planktonic foraminifera, benthic foraminifera, calcareous nannofossils, the ratios of calcareous to siliceous microfossils, and the determination of carbonate contents in the surface sediments of the northeastern South china Sea, it has been found that the carbonate contents, the abundance of planktonic foraminifera and calcareous nannoplankton, and the ratio of calcareous microfossils decrease rapidly while the ratio of the benthic foraminifera to the total foraminiferal fauna, specific value of siliceous microfossils, and the percentage of the agglutinated tests in the benthic foraminiferal fauna increase with the water depth. The results indicate that the microfossils abundance and ratio, and the carbonate content are closely related to the carbonate lysocline and carbonate compensation depth (CCD) in the study area. In addition, the carbonate lysocline and the CCD are different between the southern and northern parts of the South china Sea. Both the lysocline and the CCD are deeper in the south with 2 600 and 3.600 m than in the north with 2 200 and 3.400 m, respectively.

关键词： microfossils carbonate lysocline depth carbonate compensation depth (CCD) surface sediments South china Sea (SCS)

Exploring cyclic changes of the ocean carbon reservoir

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Chinese Science Bulletin 2003年第23期48卷 2536-2548页

作者： WANG Pinxian, TIAN Jun, CHENG Xinrong, LIU Quanlian & XU Jian key laboratory of marine {3., Ministry of Education, tongji Uni-versity, shanghai 2.0092. china key laboratory of marine {3. Ministry of Education Tongji University Shanghai China

A 5-Ma record from ODP Site 1143.has re-vealed the long-term cycles of 400—500 ka in the carbon isotope variations. The periodicity is correlatable all over the global ocean and hence indicative of low-frequency changes in the ocean carbon reservoir. As the same periodicity is also found in carbonate and eolian dust records in the tropical ocean, it may have been caused by such low-latitude proc-esses like monsoon. According to the Quaternary records from Site 1143.and elsewhere, major ice-sheet expansion and major transition in glacial cyclicity (such as the Mid-Brunhes Event and the Mid-Pleistocene Revolution ) were all pre-ceded by reorganization in the ocean carbon reservoir ex-pressed as an episode of carbon isotope maximum (d 13.max), implying the role of carbon cycling in modulating the glacial periodicity. The Quaternary glacial cycles, therefore, should no more be ascribed to the physical response to insolation changes at the Northern Hemisphere high latitudes alone; rather, they have been driven by the 揹ouble forcing? a combination of processes at both high and low latitudes, and of processes in both physical (ice-sheet) and biogeochemical (carbon cycling) realms. As the Earth is now passing through a new carbon isotope maximum, it is of vital impor-tance to understand the cyclic variations in the ocean carbon reservoir and its climate impact. The Pre-Quaternary varia-tions in carbon and oxygen isotopes are characterized by their co-variations at the 400-ka eccentricity band, but the response of d 13. and d 18O to orbital forcing in the Quater-nary became diverged with the growth of the Arctic ice-sheet. The present paper is the second summary report of ODP Leg 184 to the South china Sea.

关键词：海洋 ODP 海洋钻探工程碳循环南中国海地层学

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

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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, Qingdao 266003. china 2. Shandong key laboratory of Sea Floor Resource and Exploration Technique, Qingdao 266003. china 3. Qingdao Institute of marine geology, Qingdao 266071, china 4. College of marine Environment, Ocean university of china, Qingdao 266003. china 5. First Survey Team of marine geology, shanghai Bureau of Petroleum, shanghai 201208, china College of marine Geo-science Ocean University of China Qingdao China Shandong key laboratory of Sea Floor Resource and Exploration Technique Qingdao China Qingdao Institute of marine geology Qingdao China College of marine Environment Ocean University of China Qingdao China First Survey Team of marine geology Shanghai Bureau of Petroleum 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

Mesozoic subduction-accretion zone in northeastern South china Sea inferred from geophysical interpretations

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Science china Earth Sciences 2006年第5期49卷 471-482页

作者： ZHOU Di1, WANG Wanyin2, WANG Jialin3. PANG Xiong4, CAI Dongsheng5 & SUN Zhen1 1. key laboratory of Marginal Sea geology, South {3. Sea Institute of Oceanology, Chinese Academy of Sciences, Guang- zhou 5103.1, {3. 2. College of Geological and Topographical Engineering, Chang’an university, Xi’an 710054, {3. 3. key laboratory of marine geology, tongji university, shanghai 2.0092. china 4. {3. National Offshore Oil Co. Limited – Shenzhen Branch, Shenzhen 518067, {3. 5. {3. National Offshore Oil Co. Limited – Research Center, Beijing 100027, {3. key laboratory of Marginal Sea geology South China Sea Institute of Oceanology Chinese Academy of Sciences Guangzhou China College of Geological and Topographical Engineering Chang’an University Xi’an China key laboratory of marine {3. Tongji University Shanghai China china National Offshore Oil Co. Limited — Shenzhen Branch Shenzhen China china National Offshore Oil Co. Limited — Research Center Beijing China

A segment of Mesozoic subduction-accretion zone was inferred across thenortheastern South china Sea at approximately NE450 orientation. Basic evidence includes thefollowing: A belt of peek gross horizontal Bouguer gravity gradient (PGHGBA) is comparable in sizeand intensity to that of the Manila subduction-accretion zone. A belt of high positive magneticanomalies appears to the north and sub-parallel to the PGHGBA, representing the volcanic arcassociated to the subduction zone. The PGHGBA crosses obliquely both Cenozoic structures and presentseafloor topography, indicating a pre-Cenozoic age. The segment is offset left-laterally byNW-running strike-slip faults, in concord with the Mesozoic stress field of South china. Inaddition, the existence of the subduction zone is supported by wide-angle seismic data obtained indifferent years by different institutions. At approximate localities, a north-dipping ramp of Mohosurface is indicated by records of ocean-bottom seismometers, and a strong reflector about 8 kmbeneath the Moho reflector is indicated by both OBS and long-cable seismic records. Theidentification of a segment of Mesozoic subduction zone in NE South china Sea fills nicely the gapof the Great Late Mesozoic Circum SE Asia Subduction-acrretion Zone, which extended from Sumatra,Java, SE Kalimantan to N Palawan, and from Taiwan, Ryukyu to SW Japan.

关键词： Mesozoic, subduction zone, SE Asia, NE South china Sea, geophysics.

The genus Neomonoceratina (Crustacea: Ostracoda) from the Cainozoic of the West Pacific margins

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Acta Oceanologica Sinica 1988年第4期7卷 562-577页

作者： Zhao Quanhong and Robin Whatley Department of marine geology, tongji university, {3., china geology Department, university College of Wales, Aberystwyth, UK Dept. of marine geology Tongji Univ. Shanghai China China

Fourteen species of Neomonoceratina from the West Pacific margins are considered in the present paper, of which two species and one subspecies are described as new. Lectotypes have been designated for three of Brady’s 1868 species (N. bataviana, N. iniqua and N. rhomboidea) and also for two of Kingma’s 1948 species (N. macropora and N. microreticulata).The taxonomic confusion within the genus, particularly with respect to N. crispata, N. delicata, N. dongtaiensis, N. iniqua and N. microreticulata, is clarified and the zoogeographical implication of the distribution of the genus is discussed.

关键词： from the Cainozoic of the West Pacific margins Crustacea Ostracoda The genus Neomonoceratina West