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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 University of Geo{2., Wuhan 43.074, china 2. institute of Resources & Environments, Henan Polytechnic University, Jiaozuo 454003. china 3. Department of Computer Science, South-Central University for Nationalities, Wuhan 43.074, china 4. Laboratory of Marine geology, Tongji University, Shanghai 2.0092. china 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 ?2..3. (‰ V-PDB) to ?2..14 (‰ V-PDB), respectively, B* (Ba* = Ba/ (Al2.3.X 15%)) values from 0.015 to 0.144, TOC values from 0.02. to 0.2.%, V/Cr values from 0.3.to 2.0, Sr/Ba values from 3.2. 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.

The tectonic setting and geochemical characteristics of metamorphic basement in the southwest of the Yangtze Plate

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chinese Science Bulletin 1999年第S2期44卷 266-268页

作者： ZHANG Hongxiang~1, LIU Congqiang~2. HUANG Zhilong~2.and XU Zhifang~1 1. institute of Geophysics, {3. Academy of {2., Beijing 100101, china 2. institute of Geochemistry, {3. Academy of {2., Guiyang 550002. china institute of Geophysics Chinese Academy of Sciences Beijing 100101 China institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China

THE Dahongshan Group (in short DG) and its basement Dibadu Formation (in short DF) in the southeastof the Yangtze Plate are one of the oldest geological units in the Yangtze Plate. It is established in thisnote by means of geochemistry that the system of trench-arc-basin was formed by the subducting at thesouthwestern boundary of the Yangtze Plate in Lower Proterozoic Subera. And the existence of enrichedmantle EMI is argued by the way of trace elements geochemistry. 1 Regional geological setting There is a unit of the typical two-layer structure platform in the southwest of the Yangtze Plate. Themetamorphic basement of this platform is made up of Suberathem Dahongshan Group and SuberathemKunyang Group. Above them, there have covered expansive continental deposits from Mesozoic. The primary rocks of DG are composed of deposited limestone, sandstone and basalts. The basalts represent

关键词： Dahongshan Group(DG) Dibadu Formation(DF) tectonic geochemistry.

Megaclasts from the Carboniferous-Permian Rocks in the Langkawi Islands, Malaysia, and Their Implications

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Acta Geologica Sinica(English Edition) 1999年第1期73卷 120-122页

作者： Chen Tingyu institute of geology 2. Baiwanzhuang Road,{2. Academy of geological sciences, Beijing 10003.,china chinese Acad Geol Sci Inst Geol Beijing 100037 Peoples R China

The Ninth Regional Congress on geology, Mineral andEnergy Resources of Southeast Asia was held in KualaLumpur of Malaysia in August of 1998. After the Con-gress, the author participated in the geological fieldexcursion and investigation in the Langkawi Islands,and noted that the Carboniferous-Permian rocks con-tain megaclasts of metamorphic and pegmatitic rocks,which indicate the existence of pre-Carboniferousmetamorphism and magmatism. The observation resultsare as follows:

关键词： Malaysia and Their Implications Megaclasts from the Carboniferous-Permian Rocks in the Langkawi Islands

Slope safety control during mining below a landslide

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Science china(Technological sciences) 2005年第Z1期48卷 47-52页

作者： MIN Hong1, DENG Jianhui1, WEI Jinbing1, ZHANG Qizhong2. ZOU Jiangang2.& ZHOU Zhibin2.1. {3. of Rock and Soil Mechanics, chinese Academy of {2., Wuhan 43.071, china 2. Daye Iron Mine of WISCO, Tieshan, Daye 43.006, china institute of Rock and Soil Mechanics Chinese Academy of Sciences Wuhan China Daye Iron Mine of WISCO Daye China

The East Open Pits of Daye Iron Mine were closed in year 2.00 and the ore beyond the pit limit was planned to be mined by underground ways. In order to facilitate the smooth transition to underground mining, hanging-wall ores in the old pits were scheduled to be mined. Xiangbishan pit is one of the four mining spots selected. In 1979 when the pit was mined to around 3. m a.s.l., a landside of around 70000 m3.occurred in its North Slope, leading to the closure of the pit. The pit was then backfilled to 60 m a.s.l. to maintain the slope stability. The hanging-wall ore to be mined is just located below the old slide, so whether the slide will be reactivated and how to control its deformation and stability are the key issues concerned. Based on geological investigation and numerical analysis, it was predicted that the slide would be reactivated and a control measure using the intact ore body as a retaining wall was thus suggested. During mining, displacements were monitored to assure safety. By July, 2.03. 3.3.00 tons of ore were successfully mined. Though the observed displacement reached 8795 mm, no major failure happened. The final slope is 110 m high with an angle of 70°.

关键词： open pit mine, hanging-wall ore mining, landslide, control measure, retaining wall.

Southeastern extension of the Red River fault zone (RRFZ) and its tectonic evolution significance in western South china Sea

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Science china Earth sciences 2006年第8期49卷 839-850页

作者： LIU Baoming1,2.3. XIA Bin1, LI Xuxuan1,3. ZHANG Minqiang1,3. NIU Binhua2. ZHONG Lifeng1, JIN Qinghuan1,4 & JI Shaocheng1,5 1. Key Laboratory of Marginal Sea geology and Resources, {3. Academy of {2.,Guangzhou 510640, china 2. china University of Geo{2. (Beijing), Beijing 100083. china 3. Research Center of Science & Technology Department, CNOOC, Beijing 10002., china 4. Guangzhou Marine geological Survey, Ministry of Land & Resources, Guangzhou 510075, china 5. Ecole Polytechnique Montreal, H3.3.7, Canada Key Laboratory of Marginal Sea geology and Resources Chinese Academy of Sciences Guangzhou China china University of Geosciences (Beijing) Beijing China Research Center of Science & Technology Department CNOOC Beijing China Guangzhou Marine geological Survey Ministry of Land & Resources Guangzhou China Ecole Polytechnique Montreal Canada

Recent geophysical surveys and basin modeling suggest that the No.1 fault in the Ying- gehai basin (YGHB) is the seaward elongation of the Red River fault zone (RRFZ) in the South china Sea (SCS). The RRFZ, which separates the South china and Indo{2. block, extends first along the Yuedong fault, offshore of Vietnam, and then continues southward and breaks off into two branches: the Lupar fault and the Tinjia fault. The southern extension of the Lupar fault dies out beneath the NW Borneo while the Tinjia fault extends southeast and reaches the Brunei-Sabah area. According to the gravity and geomagnetic data, and the tectonic evolution of the basins, there are different evolution histories between the Wan’an basin (WAB) and the basins in the Nansha block. The Tinjia fault may be the boundary between the Balingian block and the Nansha block. Hence, the line linking the Yue- dong fault and the Tinjia fault, which both are continental margin faults and strike-slip ones in the {3. evolution histories, constitute the boundary between the Indo{2. and Nansha block. The Lupar fault, in contrast, is an intraplate fault within the Indo{2. block. The results provide new hints for reconstructing the tectonic evolution history of the RRFZ and the opening of the SCS, and also a framework for hydrocarbon prospecting in the region.

关键词： Red River fault zone, tectonic evolution, fault, extension, western South china Sea.

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 china Sea {2. of Oceanology, chinese Academy of sciences, Guang- zhou 5103.1, china 2. College of geological and Topographical Engineering, Chang’an University, Xi’an 710054, china 3. Key Laboratory of Marine geology, Tongji University, Shanghai 2.0092. china 4. china National Offshore Oil Co. Limited – Shenzhen Branch, Shenzhen 518067, china 5. china National Offshore Oil Co. Limited – Research Center, Beijing 10002., china 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 geology 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.

Automated detection of lunar craters based on object-oriented approach

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chinese Science Bulletin 2008年第23期53卷 3699-3704页

作者： YUE ZongYu1,2.3.4, LIU JianZhong3.& WU GanGuo2.1 institute of Remote Sensing Application, {3. Academy of {2., Beijing 100101, china 2.3. University of Geo{2. (Beijing), Beijing 100083. china 3.National Astronomical Observatories of {3. Academy of {2., Beijing 100012. china 4 Department of {13. {2., The University of Texas at San Antonio, San Antonio, TX 782.9, U.S.A institute of Remote Sensing Application Chinese Academy of Sciences Beijing China china University of Geosciences (Beijing) Beijing China National Astronomical Observatories of chinese Academy of sciences Beijing China

The object-oriented approach is a powerful method in making classification. With the segmentation of images to objects, many features can be calculated based on the objects so that the targets can be distinguished. However, this method has not been applied to lunar study. In this paper we attempt to apply this method to detecting lunar craters with promising results. Craters are the most obvious features on the moon and they are important for lunar geologic study. One of the important questions in lunar research is to estimate lunar surface ages by examination of crater density per unit area. Hence, proper detection of lunar craters is necessary. Manual crater identification is inefficient, and a more efficient and effective method is needed. This paper describes an object-oriented method to detect lunar craters using lunar reflectance images. In the method, many objects were first segmented from the image based on size, shape, color, and the weights to every layer. Then the feature of "contrast to neighbor objects" was selected to identify craters from the lunar image. In the next step, by merging the adjacent objects belonging to the same class, almost every crater can be taken as an independent object except several very big craters in the study area. To remove the crater rays diagnosed as craters, the feature of "length/width" was further used with suitable parameters to finish recognizing craters. Finally, the result was exported to ArcGIS for manual modification to those big craters and the number of craters was acquired.

关键词：自动化检测月球环形山地貌

A new species of Macrocnemus (Reptilia: Protorosauria) from the Middle Triassic of southwestern china and its palaeogeographical implication

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Science china Earth sciences 2007年第11期50卷 1601-1605页

作者： LI Chun1, ZHAO LiJun2.& WANG LiTing3.1 institute of Vertebrate Paleontology and Paleoanthropology, chinese Academy of {2., Beijing 100044, china 2.Zhejiang Museum of Nature History, Hangzhou 3.0012. china 3.geological Survey of Guizhou Province, Guiyang 550005, china institute of Vertebrate Paleontology and Paleoanthropology Chinese Academy of Sciences Beijing China Zhejiang Museum of Nature History Hangzhou China geological Survey of Guizhou Province Guiyang China

A new species of the terrestrial protorosaur Macrocnemus is briefly described and named Macrocne-mus fuyuanensis sp. nov. The specimen was found from the marine Triassic of Yunnan Province, southwestern china. It differs from the type species M. bassanii in having the following characters: (1) 17 or 18 dorsal vertebrae; (2. relatively long humerus; and (3. femur longer than tibia. M. fuyuanensis is the only record of the genus outside Monte San Giorgio area and the first definite terrestrial reptile found from the marine Triassic of china. The age of the fossil-bearing Zhuganpo Member of the Falang Formation is believed to be the Ladinian based on associated vertebrate fauna. The existence of Mac-rocnemus in the limestone suggests the presence of a terrestrial ecosystem which probably originated from the Anisian and well developed in the Ladinian in this region. The island system along the north-coast of Tethyan during the Triassic was probably an important route for the exchanges of reptiles, especially the terrestrial reptiles between the west and east.

关键词： Protorosauria,Middle Triassic,Ladinian,Yunnan,terrestrial reptile

Zircon and apatite fission track analyses on mineralization ages and tectonic activities of Tuwu-Yandong porphyry copper deposit in northern Xinjiang, china

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Science china Earth sciences 2007年第12期50卷 1787-1795页

作者： YUAN WanMing1,BAO ZengKuan2.DONG JinQuan2.GUO ZhaoJie3.& DENG Jun1 1 State Key Laboratory of geological Processes and Mineral Resources,{3. University of Geo{2.,Beijing100083.{3. 2.Laboratory of Nuclear Analysis Techniques,institute of High Energy Physics,chinese Academy of {2.,Beijing 10003.,{3. 3.Department of geology,Peking University,Beijing 100871,{3. State Key Laboratory of geological Processes and Mineral Resources China University of Geosciences Beijing China Laboratory of Nuclear Analysis Techniques Institute of High Energy Physics Chinese Academy of Sciences Beijing China Department of geology Peking University Beijing China

The mineralization ages reported in the past in the Tuwu-Yandong copper district not only are different,but also fall into the Hercynian *** study has achieved 9 zircon and 7 apatite fission track analysis *** zircon fission track ages range from 158 Ma to 2.9 Ma and the apatite ages are between 64 Ma and 140 *** mineralization accords with the regional tectonics in the copper *** consider that the zircon fission track age could reveal the mineralization age based on annealing zone temperature of 140―3.0℃ and retention temperature of ～2.0℃ for zircon fission track,and metallogenetic temperature of 12.―3.0℃ in this ore *** three mineralization epochs have been identified,i.e.,2.9―2.6 Ma,2.2.2.0 Ma and 165―158 Ma,and indicate occurrence of the min-eralization in the Indosinian and Yanshan *** to apatite fission track ages,the three tectonic-mineralizing epochs are 140―13.0}Ma,109―97 Ma and 64 Ma,which means age at about 100℃ after the *** three epochs lasted 146 Ma,108 Ma and about 100 Ma from ～2.0℃ to ～100℃ and trend decrease from early to *** is shown by the fission track modeling that this district underwent three stages of geological thermal histories,stable in Cretaceous and cooling both before Cretaceous and after 2. Ma.

关键词： mineralization age, tectonic epoch, fission track, zircon, apatite, Tuwu-Yandong, Xinjiang