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A paleontological perspective of vertebrate origin

Chinese Science Bulletin 2003年第8期48卷 725-735页

作者： SHU Degan Early Life Institute & Department of Geology, Northwest university, Xi抋n, 710069, china {2. of earth sciences and resources, china university of geosciences, Beijing, 100083, china (e-mail: elidgshu@ ***) Early Life Institute & Department of Geology Northwest University China School of Earth Sciences and Resources China University of Geosciences

The Early Cambrian Haikouichthys and Haikouella have been claimed to be related to contribute in an important way to our understanding of vertebrate origin, but there have been heated debates about how exactly they are to be interpreted. New discoveries of numerous speci-mens of Haikouichthys not only confirm the identity of pre-viously described structures such as the dorsal and the ven-tral fins, and chevron-shaped myomeres, but also reveal many new important characteristics, including sensory or-gans of the head (e.g. large eyes), and a prominent notochord with differentiated vertebral elements. This 揻irst fish?ap-pears, however, to retain primitive reproductive features of acraniates, suggesting that it is a stem-group craniates. A new order (Myllokunmingiida) and a new family (Myllo-kunmingiidae) are erected, and a new species, Zhongjianich-thys rostratus (gen. et sp. nov.), is described herein. Over 1400 newly-discovered specimens of Haikouella provide a wealth of anatomical information on this organism. It differs from chordates in many organs and organ systems, including the skin, muscles, respiratory, circulatory and nervous sys-tems. In contrast, its body-design resembles that of vetuli-colians, and the presence of a 搕ransitional?nervous system with both dorsal and ventral nerve cords suggests an affinity with living hemichordates. On the basis of these and other recent findings of fossil deuterostomes, a five-step hypothesis for vertebrate origin is proposed, intended to bridge the long- standing gap between protostomes and vertebrates. Four of the five steps accord with established ideas current in modern evolutionary zoology. Evidence for the first step is obtainable only from fossils, and specifically from fossils found from South china, hence the crucial importance of S. china sites for our understanding of early vertebrate origins and evolution. Accordingly, South china is suggested as the oldest-known birthplace of the whole vertebrates.

关键词：脊椎动物动物起源寒武纪中国南部地区

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Identification of Hydrocarbon Potential of Talhar Shale: Member of Lower Goru Formation Using Well Logs Derived Parameters, Southern Lower Indus Basin, Pakistan

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Journal of earth Science 2018年第3期29卷 587-593页

作者： Muhsan Ehsan Hanming Gu Malik Muhammad Akhtar Saiq Shakeel Abbasi Zaheen Ullah Institute of Geophysics and Geomatics China University of Geosciences Department of earth and Environmental sciences Bahria University Islamabad school of Environmental Studies China University of Geosciences Faculty of earth resources China University of Geosciences

Using well logs data only, the evaluation of shale gas hydrocarbon potential of Talhar Shale Member of Lower Goru Formation has been a challenge in Southern Lower Indus Basin in Pakistan. Well logs data analysis is helpful to evaluate the gas potential of source shale rocks. We introduced and applied empirical and graphical method to fulfil this task and derived geochemical parameters from well logs data. The method mentioned is cheap and fast. Talhar Shale has kerogen type Ⅲ and type Ⅱ which are montmorillonite clay and have potential to produce oil and gas. Talhar Shale has better sorption property. Empirical formulas are used to derive parameters, using well logs of porosity, density and uranium. Porosity and volume of kerogen, calculated from density log, give average values of 11.8% and 11.4%. Average value of level of maturity index （LMI） derived from log is 0.54, which indicates that it is at the early stage of maturity. Vitrinite reflectance is between 0.5%-0.55% as calculated by graphical method and empirical formula. Talhar Shale is at onset of oil generation, with main products of oil and gas. It is a good potential source in the study area.

关键词： Talhar Shale kerogen type sorption property thermal maturity vitrinite reflectance(Ro) Southern Lower Indus Basin.

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Nitrogen isotopic composition of plant-soil in the Loess Plateau and its responding to environmental change

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Chinese Science Bulletin 2009年第2期54卷 272-279页

作者： LIU WeiGuo1,2.& WANG Zheng1,3 1 State Key Laboratory of Loess and Quaternary Geology, Institute of earth Environment, Chinese Academy of sciences, Xi’an 710075,{2. 2.Xi’an Jiaotong university, school of Human Settlement and Civil Engineering, Xi’an 710049,{2. 3 Graduate university of Chinese Academy of sciences, Beijing 100049,{2. Chinese Acad Sci Inst Earth Environm State Key Lab Loess and Quaternary Geol Xian 710075 Peoples R China.

The nitrogen isotope of soil is of emerging significance as an indicator of climatic change and biogeochemical cycle of nitrogen in nature systems. In this paper, the nitrogen content and isotopic composition of modern ecosystems from arid and semiarid Loess Plateau in northwestern china, including plant roots and surface soil, were determined to investigate trends in δ15N variation of plant roots and soil along a precipitation and temperature gradient in northwestern china under the East Asian Monsoon climate condition. The δ15N values of surface soil from the study area vary from ?1.2. to 5.8‰, but from -5.1‰ to 1.9‰ in the plant roots. Our results indicate that (1) although the isotopic compositions of both plant roots and surface soil change with a similar trend along the climate gradient, the apparent nitrogen difference between plant roots and soil existed, with -δ15N values ranging from 0.3‰ to 7.2. with average of 4.1‰; and (2. mean annual precipitation (MAP) is the dominant factor for isotopic composition of plant-soil nitrogen in the Loess Plateau, and the δ15N values are less correlated with MAT; we suggest that nitrogen isotopic composition of soil is a potential tracer for environmental changes.

关键词：氮同位素物理性质化学性质环境论

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Magnetic Structure of Archean Kongling Group from Yangtze Craton,South china

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Journal of earth Science 1998年第2期17卷 52-59页

作者： Liu Qingsheng Department of Applied Geophysics, china university of geosciences, Wuhan 430074 Gao Shan Faculty of earth {2., china university of geosciences, Wuhan 430074 Xu Qidong Faculty of earth resources, china university of geosciences, W

Densities and various magnetic parameters (susceptibility, saturation magnetization, saturation isothermal remanent magnetization and intrinsic coercivity) were measured for 2. representative rock samples of different lithologies from the Archean Kongling amphibolite to granulite facies terrain of the Yangtze craton. Metasedimentary rocks and tonalitic trondhjemitic granodioritic granitic (TTGG) gneisses show that values of susceptibility κ and saturation isothermal remanent magnetization SIRM are higher than those of amphibolites and gabbros. The felsic gneisses have averages of κ =(1 163±375)×10 -6 SI, SIRM =(18.2.±8.38) A/m and R 1=0.083 3± 0.005 7 and the metasedimentary rocks κ =(1 2.6±82.)×10 -6 SI, SIRM =(2..70±10.91) A/m and R I=0.071 4±0.02. 2. In contrast, mafic rocks have average κ =(764±316)×10 -6 SI, SIRM = (10.46±3.94)A/m and R 1=0.036±0.009 4, and are dominated by a mixed paramagnetic and ferrimagnetic behavior. Thermal magnetic analyses indicate that magnetite and maghemite of low coercivity are the major carriers of remanent magnetism in the metaclastic sedimentary rocks and TTGG gneisses. The amphibolite and gabbro contain minor amounts of magnetite and pyrrhotite. Magnetism of metaclastic sedimentary rocks and TTGG gneisses is highly heterogeneous; variation coefficients of κ and SIRM are as high as 67 % and 53 % for the former and 32.% and 46 % for the latter. mineral compositions suggest that biotite may be responsible for the higher magnetism of the metasedimentary rocks. The highest variations in κ, SIRM and R I exhibited by metasedimentary rocks can also be interpreted by their largest absolute variations in biotite mass fraction relative to mafic rocks and felsic gneisses. The average ratio ( Q ) of natural remanent magnetization to induced magnetization of felsic gneisses and metasediments is 0.47 . Ratios ( REM ) of natural remanent to sat

关键词： magnetic structure amphibolite granulite facies Yangtze craton.

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Geothermal Characteristics and Geological Implications of Major Tectonic Units in china

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Journal of earth Science 2000年第3期19卷 152-157页

作者： Wang Yang Faculty of earth sciences and {2. resources, china university of geosciences, Beijing 100083, china Wang Jiyang Institute of Geology and Geophysics, Chinese Academy of sciences, Beijing 10002., china Deng Jinfu Faculty of earth Scie

On the basis of more than 900 heat flow data in china and the surrounding seas, the authors study the geothermal characteristics of major tectonic units in china. The spatial pattern of heat flow and other thermal parameters for lithosphere exhibit significant lateral variation, originating from the Cenozoic tectonothermal activities related to the subduction of the Pacific plate and the collision between India and Asia. The mechanical strength of the crust and the seismicity of tectonic units were strongly affected by geothermal characteristics of units. The crustal heat production rate also shows the lateral heterogeneity, implying the significant lateral variation of bulk composition of the crust in china.

关键词： heat flow effective elastic thickness heat production rate of crust china.

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Helium isotope investigation on magnetic reversal boundaries of loess-paleosol sequence at Luochuan, central Chinese Loess Plateau

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Chinese Science Bulletin 2007年第17期52卷 2407-2412页

作者： DU XueQing1,6, WANG YongHong2. REN JianGuo3, YE XianRen4 & LU HuaYu5,1 1 State Key Laboratory of Loess and Quaternary Geology, Institute of earth Environment, Chinese Academy of sciences, Xi’an 710075,{2. 2.College of Marine geosciences, Ocean university of{2., Qingdao 2.6003,{2. 3 National Natural Science Foundation of{2., Beijing 100085,{2. 4 Lanzhou Research Center for Petroleum and Natural Gas resources, Institute of Geology and Geophysics, Chinese Academy of sciences, Lanzhou 730000,{2. 5 Key Laboratory of Coast and Island Development, {12. of Geographic and Oceanographic sciences, Nanjing university, Nanjing 2.0093,{2. 6 Graduate university of Chinese Academy of sciences, Beijing 100049,{2. State Key Laboratory of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences Xi''an 710075 China

Extraterrestrial particles have higher 3He/4He ratios than those of terrestrial sediments ( > 100 Ra versus < 0.03 Ra, where Ra is the 3He/4He ratio normalized to the atmospheric value of 1.4×10?6). The inter- planet... 详细信息

Extraterrestrial particles have higher 3He/4He ratios than those of terrestrial sediments ( > 100 Ra versus earth and can accumulate in deposits. IDPs sedimentation rate changes can significantly influence 3He concentration in the earth surface sediments. Since IDPs are not easy to detect in terrestrial deposits, measuring helium isotopes is a helpful approach to examine changes in IDPs. Helium concentration and helium isotopic composition magnetic substances and the quartz particles were examined for helium concen- tration and helium isotopic ratio. Results show that the 3He/4He ratio and the 3He concentrations of the magnetic substances are clearly higher than those of the bulk samples and the quartz particles, and, the 3He/4He ratio of the extracted magnetic substances is also higher than that of the average level of the earth’s crust. The higher helium content in the magnetic fractions can be explained by an influx of IDPs.

关键词：中国黄土高原古土壤氦同位素行星际尘埃颗粒反方向磁化

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Simulation studies of high-latitude magnetospheric boundary dynamics

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Science china(Technological sciences) 2004年第4期47卷 421-435页

作者： PU Zuyin1, SHI Quanqi1,3, XIAO Chijie1, FU Suiyan1, ZHANG Hui1,2. ZONG Qiugang2.& LIU Zhenxing3 1. school of earth and Space {2., Peking university, Beijing 100871, china 2. Center for Space Physics, Boston university, 72. Commonwealth Avenue, Boston, MA 02.15, USA 3. Center for Space Science and Application Research, Chinese Academy of {2., Beijing 100080, china 1. school of earth and Space {2. Peking University 100871 Beijing China 2. Center for Space Science and Application Research Chinese Academy of Sciences 100080 Beijing China 3. Center for Space Physics Boston University 725 Commonwealth Avenue 02215 Boston MA USA

Magnetic reconnection at the high-latitude magnetopause is studied using 2.5-dimensional Hall-MHD simulation. Concentric flow vortices and magnetic islands appear when both Hall effect and sheared flow are considered. Plasma mixing across the magnetopause occurs in the presence of the flow vortices. Reconnected structure generated in the vicinity of the subsolar point changes its geometry with increasing flow shear while moving to high latitudes. In the presence of flow shear, with the Hall-MHD reconnection a higher reconnection rate than with the traditional MHD is obtained. The out-of-plane components of flow and magnetic field produced by the Hall current are redistributed under the action of the flow shear, which makes the plasma transport across the boundaries more complicated. The simulation results provide some help in understanding the dynamic processes at the high latitude magnetopause.

关键词： magnetopause, entry layer, magnetic reconnection, vortex reconnection, Hall effect, flow shear.

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Syndepositional Fault Controlling on Depositional Filling of the Third Member of Shahejie Formation in Beitang Sag

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Journal of earth Science 2009年第6期20卷 949-958页

作者：黄传炎王华肖敦清陈思王家豪廖远涛 Faculty of earth resources China University of Geosciences State Key Laboratory of Geological Processes and mineral resources China University of Geosciences Key Laboratory of Tectonics and Petroleum resources of Ministry of Education China University of GeosciencesWuhan Research Institute of Exploration and Development PetroChina Dagang Oilfield Company

In the continental lake basin whose structures were extraordinarily active, tectonism is an important factor in controlling the sequence and the depositional filling of the basin. This article reports the assemble patterns of syndepositional fault in the third member of Shahejie （沙河街） Formation in Beitang （北塘） sag. The results show that the comb-shape fracture system and the fracture transformation zone were developed in Beitang sag. These assemble patterns obviously controlled the sand-body and spatial distribution of sedimentary system. However, the steep slope belt of fault terrace, the multistage slope belt and the low uplift gentle slope belt controlled the development of sequence styles. Analyses of the spatial-temporal relationship of the assemble pattern of syndepositional faults and the sedimentary system help predict the favorable exploration zone.

关键词： Beitang sag syndepositional fault structural slope break zone the third member of Shahejie Formation.

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Laser probe ^(40)Ar/^(39)Ar dating of mica on the deformed rocks from Altyn Fault and its tectonic implications,western china

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Chinese Science Bulletin 2001年第4期46卷 322-325页

作者： LIU Yongjiang, YE Huiwen, GE Xiaohong, CHEN Wen, LIU Junlai, REN Shoumai & PAN HongxunCollege of earth sciences, Changchun {2. of Science and Technology, Changchun 130061, china Graduate school, china university of geosciences, Beijing 100083, china Laboratory of Isotopic Geochronology, Institute of Geology, Ministry of Land and resources of china, Beijing 100037, china College of earth sciences Changchun University of Science and Technology Changchun China Graduate school China University of Geosciences Beijing China Laboratory of Isotopic Geochronology Institute of Geology Ministry of Land and Resources of China Beijing China

The samples of Caledonian mylonitized granite and Jurassic meta-sedimentary rocks were collected in the north of Dangjinshan Pass, Qaidam gate fault-valley and Gesi fault-valley. Detailed studies under the microscope and electronic microscope suggest that all the samples contain the syntectonic-growing minerals such as white mica, chlorite, sericite, biotite, etc. By dating these minerals, we got a group of 40Ar/39Ar laser probe isochronal ages of 89-92.Ma and apparent ages of (46.6±6.4) Ma. The ages ranging from 97 to 46 Ma were reported for the first time in the isotopic dating researches of the Altyn Fault The isochronal age group of (98-89) Ma indicates that a ductile strike-slip event, with low-grade metamorphism, began in late Cretaceous. This suggests that the strike-slip movement of the Altyn Fault should be related to the formation of the so-called west tectonic syntaxis in the Nepal-western Kunlun area.

关键词： Altyn Fault 40Ar/39Ar age strike-slip movement.

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Is the PhyloCode better than Linnaean system?—— New development and debate on biologi-cal nomenclatural issues

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Chinese Science Bulletin 2003年第3期48卷 308-312页

作者： GAO Keqin & SUN Yuanlin school of earth and Space {2., Peking university, Beijing 100871, china school of earth and Space {2. Peking University Beijing 100871 China

The Linnaean system provides ultimate means governing biological nomenclature and classification. With series of modification, this system has admirably served bio-logical sciences for some 2.0 years. The new PhyloCode, however, advocates the phylogenetic nomenclature that radically alternates the current nomenclatural rules. The new proposals upset many systematic biologists and have provoked hot debate on nomenclatural issues. Binomial no-menclature and hierarchical classification are the key com-ponents of the Linnaean system. Proposed abandonment of these in the PhyloCode is widely criticized for it would not help to promote systematics but create chaos. It is not the Linnaean system but the phylogenetic nomenclature that should be abandoned.

关键词：生物分类生物命名法林奈系统系统代码法特点

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