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    2016, Volume 23 Issue 6
    15 November 2016
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    Division of tectonic stages and tectonic evolution in China.
    BO Gui-Tang, LIU Song-Nian, XIAO Qiang-Hui, ZHANG Ke-Shen, YIN Fu-Guang, HAO Guo-Jie, JIA Man-Sheng, LIN Fei, YUAN Si-Hua
    2016, 23(6): 10-23. 
    DOI: 10.13745/j.esf.2016.06.001

    Abstract ( 1293 )   PDF (4690KB) ( 2439 )  

    According to the thinking of Mr. Wang Hongzhen on the tectonic evolution stage and the active global tectonic theories, following the principles of comparative structural geology, i.e. the present is the key to the past, and taking spatial and temporal texture analysis of tectonic faices and environment as the main approach in which the suture zone, orogenic system and continental block are treated as three first rank tectonic units, and from the point of view of irreversible evolution of supercontinent convergence and rifting and oceancontinent transformation theory to recognize and understand the constituent characteristics of Chinese tectonic spatial and temporal texture, we propose that the tectonic evolution of China can be divided into three stages. The ArcheanPreNanhuaian (>1800820 Ma): continental nucleus formed from the Archean (>2800 Ma); protoplate tectonics started, ocean and continent differentiated, paleoarc basin system developed in Neoachrean (28002500 Ma), and in North China blocks, TTG gneiss distributes widely: Jining, South LiaoheJingshan arc basin system and Songshan and Hutuo rift developed during the Paleoproterozoic (25001800 Ma), and basement of the North China platform formed ~1800 Ma: Yanliao, XiongerXiyanghe and ZhartaiBayan Obo epicontinental rift developed in the Mesoproterozoicearly Neoproterozoic (820 Ma ago) after cratonization of the North China platform; Mesoproterozoic epicontiental rift developed in Yangtze and Tarim blocks, a series of arc basin systems formed in the early Neoproterozoic, and moreover, Yangtze and Tarim platform basement formed, which amalgamated with Rodinia. The NanhuaianMiddle Triassic (820227 Ma): (1) The NanhuaianSinian: Rodinia broke up and developed volcanosedimentary rocks and tillites related to rifting event in the Nanhuaian, PaleoAsian, ProtoTethys and Sinian Ocean spread, epicontinental rift and rifted basin developed in Yangtze and Tarim plateform, and Huanan Ocean shrank to relict oceanic basin. (2) The CambrianEarly Ordovician: PaleoAsian and ProtoTethys Ocean expanded continually, a group of massifs splitted from Yangtze and Tarim platform, and passive continental margins and polyisland arc basin systems formed in extensional environment. Rifted basin developed in the north Indian craton during the Cambrian, covered by Ordovician carbonate platform (O12). (3) The Late OrdovicianSilurian: PaleoAsian Ocean subducted bidirectionally, AlatiXingmeng polyisland arc basin systems related with northward subduction, southward subduction controlled TianshanJunggarBeishan polyisland arc basin sytems and Odor Sum accretionary arc basin system. Northward subduction of South Tianshan Ocean resulted in Central Tianshan island. Passive continental margins developed in north of Yangtze, Tarim and Indian platform. Sinian and Huanan Ocean extincted in Silurian. United PanCathaysia formed including Yangtze, Tarim and North China, QinQiKun orogenic system and Cathaysia orogenic system located in its southwest and southeast margin, respectively. (4) The DevonianMiddle Permian: PaleoAsian and South Tianshan Ocean shrank and disappeared, TianshanJunggarBeishan and AltaiXingmeng orogenic systems (C2P2) formed. Epicontinental sea basin developed in North China Platform after overall uplift (O3C1). Epicontinental rifted basin developed in Yangtze platform. Northward and southward subduction of PaleoTethys Ocean controlled North QiangtangSanjiang polyisland arc basin systems and Gangdese epicontinental arc (CP), respectively. (5) Late PermainMiddle Triassic: Basinmountain tectonic framwork formed in northwest China, Hegang epicontinental arc was controlled by northward subduction of Nadanhada Ocean. Epicontinental arc in both sides of QamdoSimao massif developed owing to eastward and westward subduction of Lancanjiang and JinshajiangAilaoshan backarc oceanic basin, respectively. Gangdese arc basin system was controlled by the southward subduction of PaleoTethys Ocean. Panxi rift as a result of the activity of Emeishan large igneous province developed in west Yangtze platform. The Late TriassicNeogene (2272.6 Ma): East China epicontinental arc formed in the late Mesozoic, basinmountains developed in northwest China and HimalayaGangdese polyisland arc basin systems formed in southwest China. Backarc rifted and faulted basin formed in eastern coastal of China in the Cenozoic, and HimalayaGangdese orogenic systems formed as a result of IndiaAsia collision, simultaneously. Tibetan plateau intensively uplift since the Miocene.

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    Palaeogeographic distribution and tectonic evolution of OPS in China.
    ZHANG Kexin,HE Weihong,XU Yadong,LUO Mansheng,SONG Bowen,KOU Xiaohu
    2016, 23(6): 24-30. 
    DOI: 10.13745/j.esf.2016.06.002

    Abstract ( 372 )   PDF (1221KB) ( 1204 )  

    The classification of the Ocean Plate Strata (OPS) in China has been proposed and the palaeogeographic distribution of the OPS and NeoproterozoicCenozoic tectonic evolutions in China have been summarized, based on the idea of tectonic facies analysis and numerous materials used in the editing of the “Sedimentary Tectonic Map of China (1∶2500000)”. The tectonic evolutions of the six major belts in China have been outlined in this paper. The oceancontinent converting of the PaleoAsian Ocean in northern China presented diachronous phenomenon from west to east, namely, the converting taking place in the EarlyLate Carboniferous in the west, and in the MiddleLate Permian in the east. The KuanpingFoziling ophiolitic mélange zone is considered as a product of the demise of the ocean between North China and Yangtze. The oceancontinent converting of the Central Orogenic Belt of China happened during the late Late Ordovician along the QilianAltun area in the north and took place in the late Early Triassic along the KunlunQinling area in the south. The LongmucuoShuanghu, ChangningMenglian, BangonghuNujiang mélange zone in Tibet is regarded as the suture zone between Laurasia and Gondwanaland continents and was formed during the Cambrian to the Early Cretaceous, marking the evolution from the ProtoTethys to PaleoTethys. The JiangshaoChenzhouQinfang mélange zone is considered as another suture zone, marking the demise of Huanan Ocean between Yangtze Block and Cathay AccretedBlock, and the main collision of them happened in the Late Ordovician to the Early Silurian.

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    The concepts of inner-continental tectonic domain of Wang's theory and their application to the study of the largesized superimposed basins.
    LI Sitian
    2016, 23(6): 31-33. 
    DOI: 10.13745/j.esf.2016.06.003

    Abstract ( 304 )   PDF (795KB) ( 733 )  

    It is a great challenge to us to apply the plate tectonic theory to the East Asia Paleocontinent which has very complicated tectonic framework and geological evolution history. Prof. WANG Hongzhen proposed the tectonic domain concept as the first order tectonic unit in continent, and proposed the convergent lithosphere consumption zones as a boundary between the tectonic domains, and based upon the concepts a new tectonic and oilbearing basins map had been constructed. The main large superimposed basins (Tarim, Sichuan, Ordos, etc.) were all developed in the stable center area of the stable Precombrain basement. The relative stable condition may have been a very important condition for oil and gas accumulation. The multistage tectonic movement controlled the basin evolution history and could be correlated with the interaction of geological events between the domains.

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    Crustal convergent and accretional consumption zones, and continent-continent collisional orogenes and subductionaccretional orogenes: Records from the igneous petrotectonic assemblages.
    DENG Jinfu,LIU Cui,DI Yongjun,FENG Yanfang,SU Shangguo,XIAO Qinhui,ZHAO Guochun
    2016, 23(6): 34-41. 
    DOI: 10.13745/j.esf.2016.06.004

    Abstract ( 352 )   PDF (1233KB) ( 789 )  

    This paper discusses the crustal accretional and convergent consumption zones, plate tectonomagmatic cycle, subductionaccretional orogenes and continentcontinent collisional orogenes. The subductionaccretional orogenic architecture is composed of subductionaccretional complex and magmatic arcs. Both the igneous petrotectonic assemblages of the Stype and the peralkaline Atype granites, related to the continentcontinent collision and the postorogeny, respectively, are discussed. Finally, the collision frameworks of three cratons of China, and of both the Siberia and India continents are discussed: (1) the collision of northwestern margin of Tarim with southwestern margin of Siberia was underway during the Carboniferous, and ended up at the Early Permian; (2) the collision of three cratons of China was underway during Early and Middle Triassic, and ended up at the Late Triassic; (3) the final collision of the China and Siberia was underway from the later Early Cretaceous to the Late Cretaceous; (4) during the Cenozoic the collision of China and India is underway.

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    Openingclosing tectonics: Exploration of a new idea on global tectonics.
    YANG Weiran,JIANG Chunfa,ZHANG Kang,GUO Tieying
    2016, 23(6): 42-60. 
    DOI: 10.13745/j.esf.2016.06.005

    Abstract ( 281 )   PDF (3048KB) ( 701 )  

    The 6070s in the 20th century, was the most active period in academic thinking within Chinese geotectonics circle. In the year 1979 at The 2nd AllChina Conference on Structural Geology a memorable scene appeared that the leading lights of the 8 tectonic schools in China showed up at the same stage to illustrate their own points of view. After that, the leading light of the theory of polycyclic tectonics, academician Huang Jiqing and one of his successors Jiang Chunfa,the leading light of the theory of fault block tectonics, academician Zhang Wenyou and one of his successors Zhang Kang, the leading light of the theory of regional geotectonics, academician Ma Xingyuan, and one of his successors Yang Weiran, proposed respectively at about the same time the polycyclic accordion shaped openingclosing tectonics, the faultblock openingclosing tectonics and the “opening” “closing” tectonics. The 3 tectonic schools reached at the same goal by different routes and made a concerted effort to construct the openingclosing tectonic theory with Chinese characteristics.The openingclosing tectonics deals with the openingclosing movement and the textural structural features and regularities of the geological bodies formed. The present paper is a summary on the fresh round research results of the openingclosing tectonics. (1) The fundamental attribute of the openingclosing tectonics is that openingclosing movement is the major form of the movements of all geological bodies. It reveals the internal relation and intrinsic characteristics of various geological movements. Opening and closing are a pair of elemental contradictions in geodynamics. Both of them are mutual dependent and antagonistic, and are transformable, and the positioning of the time and space of the turning point (zone) of the transformation is both of theoretical and practical significance. (2) The openingclosing rule in geosciences is a summary on the regularities of openingclosing movement including the ranks and layering in various scales of openingclosing tectonics, the temporal cyclicity, the spatial complementation, the orientation in evolution and the summing up of the migration evolution model of the openingclosing movement, i.e., from simple to complex and starting from a point to a line and then spreading over to a plane. (3) Several important concepts in the research of openingclosing tectonics are that the markers of opening and closing are referred to various geological phenomena which can be used in determining the attribute of the opening and closing and are the fundamental information in the study of openingclosing tectonics; the openingclosing formation and formation sequence are the studies on the characteristics of material assemblage during the openingclosing process which reflect the geological setting of the material assemblage and the evolutional stages of the openingclosing tectonics; the classification of types of openingclosing tectonics is based on the comprehension of openingclosing markers in summing up the regularity of association of openingclosing movements in various ranks and layers. It can reflect the various evolution stages of continentocean openingclosing movement. At present, there are 8 types of openingclosing tectonics had been summarized. The unit in openingclosing tectonics is a summary on the comprehensive characteristics and the regularities of spatial distribution of openingclosing tectonics. A new concept of tectonic unit of continental rank—the openingclosing tectonic assemblage has been proposed. It should be strengthened that all the geological bodies in the tectonic assemblage are genetically related each other and are regularly evolved from point to line and then spreading to the plane surrounding a core continental block. The first author of this paper had subdivided the central part of Asia into 4 openingclosing tectonic assemblages. (4)The layered structure of the Earth and various geological structures are formed under the common action between the openingclosing movement and the rotationing movement. Among them the openingclosing movement is the leading one. The rotationing movement regulates the openingclosing movement to reach a relatively stable dynamic equilibrium state. It can be called the openingclosing rotationing tectonic system. The stable dynamic equilibrium can once or locally be destroyed. The process through regulation to reach a new equilibrium is called the tectonic movement, such as, the movements leading to important geological events happened in the geological history, i.e., the Caledonian, the Hercynian, the Yanshanian movements, etc. The regulation of openingclosing movement to reach equilibrium by the rotationing movement is carried out through the tiny variation of the rotation speed of the earth and the subtle difference in rotation speed between various layers of the earth. (5)The tectonic movement is a true record of the reequilibrium process through adjustment of the once or locally destructed openingclosingrotationing dynamic equilibrium system. We consider that the motivation of tectonic movement comes from the thermal energy and gravitational energy of the earth. The core of the earth is a thermal reservoir unceasingly supplying thermal energy upwards. Gravity forms the openingclosing tectonic transformation zone at the coremantle boundary which becomes the base for the thermal energyrich synthetic energy formation and accumulation. Under certain conditions the synthetic energy enriched materials ascend to the mantle and different layers in the crust which mingle or react with the source rocks forming melted thermal fluids with various peculiarities. They are the direct origin causing the production of various geological events and the formation of various geological structure. (6) The mobilism against the fixism has been disputed for a long period of time. The debate is focused at whether the crustal movement is a horizontal or vertical one. By means of temporal and spatial analyses it is likely that the crustal movement is unable to be distinguished whether it is prominent of horizontal or vertical. In fact both vertical movement and horizontal movement are coexisting in the openingclosing tectonic system. There are 2 types of openingclosing movement—the horizontal openingclosing and vertical openingclosing. Therefore, the debate about vertical movement against horizontal movement is of no practical significance and should be stopped.

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    Reconstruction of tectonopaleogeography and dynamic topography.
    LIU Shaofeng,WANG Chengshan
    2016, 23(6): 61-79. 
    DOI: 10.13745/j.esf.2016.06.006

    Abstract ( 445 )   PDF (3158KB) ( 915 )  

    The tectonopaleogeography is a science concerned with the study of tectonics and natural geography through geologic time. In the era of Big Data, with the rapid increase in computing power and efficiency as well as advancement in geodynamic simulation technology, tectonopaleogeography can be studied in the setting of global plate tectonics so that the “deep time”, protolocation and prototype paleogeography can be reconstructed. Based on a comprehensive analysis of international and domestic research findings on the geodynamic modeling softwares of GPlates and CitcomS, this paper expounds the research ideas, contents and methods of plate tectonicpaleogeographic reconstruction, technology of residual topography differentiation, and genetic relationship between dynamic topography, plate subduction and deep mantle flow. The paper also introduces the research ideas and methods of revealing plate movement, mantle dynamics with constraints of Earths surface paleogeography such as dynamic topography and others; and proposes the principles of timing, geopositioning, orienting and prototyping that should be followed in the studies of paleogeographic reconstruction and geodynamics. It is of great theoretical significance to reveal 4D geodynamics that the analysis of global plate tectonicpaleogeographic model (GPlates) is combined with that of finite element model (CitcomS) based on physical characteristics of the lithosphere and mantle, and that the investigation of dynamic topography is combined with that of mantle flow.

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    Softsediment deformation structures and their implications for tectonic evolution from Mesozoic to Cenozoic in the Longmen Shan.
    QIAO Xiufu,JIANG Mei,LI Haibing,GUO Xianpu,SU Dechen,XU Lehong
    2016, 23(6): 80-106. 
    DOI: 10.13745/j.esf.2016.06.007

    Abstract ( 356 )   PDF (6384KB) ( 487 )  

    The Longmen Shan is a mountain body composed of three main faults. The WenchuanMaoxian fault, also called the rangeback fault, constitutes the western boundary of the Longmen Shan; the YingxiuBeichuan fault is the central fault of the Longmen Shan; and the GuanxianAnxian fault, also called the rangefront fault, is the eastern boundary of the Longmen Shan. On the east of the Longmen Shan fault belt, there is a foreland basin which has been experienced different periods since the terminal of the Late Triassic. There had been rich softsediment deformation structures (SSDS) in the strata of different ages in the foreland basin from the Late Triassic to the May 12, 2008 Wenchuan earthquake (MS 8.0), including liquefaction deformation, gravitational deformation, hydroplastic deformation, and other related deformations. These deformation strata were located immediately near the three faults of the Longmen Shan, and the activities of these faults in different periods induced strong earthquakes in different periods, leading to the deformation of the sediments that had not consolidated then (seismites). The SSDS in the Upper Triassic Xiaotangzi Formation included liquefied breccia, liquefied droplet, liquefied diapir, thixotropic diapir, convolute deformation, stretched pudding, load, ballandpillow structure, pillow beds, and graded fault. In the Jurassic and Cretaceous, there were mainly coarsegrained sediments, and the main soft sediment deformation types were largescale conglomerate load structures with various shapes except liquefaction deformation found in a few horizons. In the Paleogene, there was lacustrine sediments, with fine grains, and there were large quantities of liquefaction deformation structures in the soft sediment, e.g., plunged sediment mixtures, liquefied breccia, and pillow beds. The May 12, 2008 Wenchuan earthquake (MS 8.0) induced large scale liquefaction of underground sand bed, forming a series of liquefaction deformation structures and microfeatures, e.g., liquefied dune, liquefied sheet sand, sand volcano, liquefied mound, pit landform, and chaotic accumulation. The occurrence time sequence and seismic orogenic periods of the Longmen Shan fault belt can be given with the reflection seismic results of the Longmen Shan, the paleoearthquake records and the regional structures: (1) The collision between the SongpanGarzeor orogenic belt and the Yangtze Plate occurred in the early stage of the Late Triassic, and their boundary is the current WenchuanMaoxian fault; the WenchuanMaoxian fault had thrust nappe orogenesis in the end of the Late Triassic, the mountain in the Longmen Shan region in the end of the Triassic could be called the SongpanGarze Shan, on the east of which a foreland basin was formed; the continental dynamic action period of the Late Triassic Indosinian orogenic cycle was the gestation and birth stage of the Longmen Shan. (2) The thrust activity between the YingxiuBeichuan fault and the GuanxianAnxian fault occurred in the Jurassicthe Early Cretaceous, forming high mountains and the foreland basin. (3) The Early Cretaceous Longmen Shan had been already a fault belt mountain body composed of three thrust faults, and it could be called the PaleoLongmen Shan, with mountain altitude >3500 m. (4) The activities of these three faults in the Paleogene induced the Paleogene soft sediment deformation, but the faults did not have thrust nappe orogenesis, and the sediments were finegrained lacustrine sediments, so the Paleogene was a stage with seismic activities but without orogenesis. (5) The Mesozoic Longmen Shan experienced multiple processes of instantaneous seismic orogenesis and quietperiod mountain range denudation lowering, and the current Longmen Shan is the product of multiple instantaneous seismic orogenic activities occurring during the Late Cenozoic. Different from those methods used for the Longmen Shan by numerous geoscience researchers, another idea, softsediment deformation structures, i.e., the paleoearthquake records was used in this paper, in other words, it is a new way to disscuss the tectonic evolution in the Longmen Shan by studying the SSDS.

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    A new model on the Mesozoic “South China Sea”(SCS): Reconstructing the Hainan marginal arc and recognizing the Tethyan SCS.
    FANG Nianqiao
    2016, 23(6): 107-119. 
    DOI: 10.13745/j.esf.2016.06.008

    Abstract ( 289 )   PDF (2315KB) ( 450 )  

    摘要:应用近期在琼南、广东、湘南和越南芽庄、大叻等地的研究成果,综合区域地质资料,从岩浆岩性质、组合与地化特征、沉积序列特征和碎屑岩组分、年代学和地层学等方面进行分析,构建起以海南岛中南部的岩浆沉积组合为典型标志、以东西向延伸为基本特征、演化过程与浙闽活动陆缘带明显有别的海南陆缘弧体系。该陆缘弧晚中生代处于华南大陆的南端,在构造地理格局上从属于特提斯域。笔者主张向北俯冲于海南陆缘弧下的“古南海”应正名为“特提斯南海”,它是特提斯多岛洋北部的边缘海,西段可能与缅、马等地的海域沟通,东段则与太平洋域相接。海南陆缘弧具有广阔的弧后区,各弧后盆地的演化进程可以对比。该弧最初似发育于晚侏罗世,早白垩世晚期和晚白垩世初期岩浆弧与俯冲造山活动达到高峰,晚白垩世发生弧后拉张,但近弧地带挤压条件下的岩浆沉积作用一直延续至晚白垩世后期(约70 Ma)。海南陆缘弧的活动时间表实际上是特提斯南海消减过程的真实反映。由于消减过程及随后发生的中南半岛在早新生代的挤出逃逸运动和现代南海的扩张作用,特提斯南海的地质记录受到极其严重的破坏,恢复特提斯南海的原貌仍是一项有待开展的艰巨工作。

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    Age of the Ondor Sum Group in western Inner Mongolia and its position in the Central Asia Orogenic Belt.
    XU Bei,XU Yan,LI Jin,LI Qunsheng
    2016, 23(6): 120-127. 
    DOI: 10.13745/j.esf.2016.06.009

    Abstract ( 351 )   PDF (1606KB) ( 519 )  

    The Ondor Sum Group (OSG) in western Inner Mongolia can be divided into two parts: the lower part consists of ferrian quartzites, metavolcanic rocks and sericite quartz schists; the upper part includes sericite quartz schists and quartzites mixed with localized carbonate rocks. In SHRIMP and ICPMS geochronometric determination, one SHRIMP peak age of 460±4 Ma and two detrital zircon peak ages of 417 Ma and 444 Ma were acquired from the metavolcanic rocks in lower part and sericite quartz schists in upper part, respectively. These new data, combined with previous zircon dating indicate OSG developed from 500 Ma to 415 Ma. Composition of OSG suggests that it formed in the continental margins of the SongliaoHunshandake block, which is called the “Ondor Sum Ocean” (OSO) in this paper, representing the Paleo Asian Ocean in China during the early Paleozoic. During the earlymiddle Paleozoic, OSO was subducted beneath the north China block in the south and XinganAngin Sum block in the north, respectively; its main part formed the northern and southern accretionary wedges whereas its marginal part became the matrix of northern and southern mélanges. Deformation and metamorphism in OSG recorded the evolution process of the eastern Central Asia Orogenic Belt. Detrital zircon analyses of OSG demonstrate that its Precambrian source area is similar with the lower Paleozoic in Mongolia and different from that in the North China Craton (NCC), indicating there were other provenances for OSG.

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    Life origin, early evolution stages, and ocean environment changes.
    SHI Xiaoying,LI Yiliang,CAO Changqun,TANG Dongjie,SHI Qing
    2016, 23(6): 128-139. 
    DOI: 10.13745/j.esf.2016.06.010

    Abstract ( 609 )   PDF (1709KB) ( 994 )  

    Increasing evidence suggests that life most likely originated in a time between ca 3.9 and 3.6 Ga on the earth, with the earliest recognizable fossils recorded in the rocks of ca 3.5 Ga. Besides carbon, water, nitrogen, hydrogen, and phosphorous are indispensable chemical elements, while clay minerals and metal sulfides are key catalysts for organic synthesis. Early environments with saline water and hydrothermal activity seem to be the most favorable hatch pool for the origin of life. Since prokaryotic organisms emerged not later than ~3.5 Ga, biosphere as an important geologic agent interacting with atmosphereocean has greatly accelerated the evolution of Earth surface systems, showing an apparent coevolution with environments. As one of the most important events in Earth history, the Great Oxygenation Event (GOE) has not only altered the earth surface environments profoundly, accelerated various geologic processes and the generation of new minerals, but also reset the ocean chemistry and element cycles. GOE resulted virtually from the onset of oxygenproducing photosynthesis, and the overall transition of ocean chemistry at ca 1.8 Ga was also closely related to microbial processes. The emergence of metazoans at the terminal Neoproterozoic and their rapid diversification at the beginning of the Phanerozoic are significant innovations in life evolution. These innovations are closely linked to the further increase of atmospheric oxygenation and the consequent changes in ocean chemistry at the times, particularly to the shrinkage of euxinic waters and the increasing availability of bioessential elements in seawater, in which microbes always play essential roles.

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    Precambrian major geological events.
    LU Songnian,HAO Guojie,XIANG Zhenqun
    2016, 23(6): 140-155. 
    DOI: 10.13745/j.esf.2016.06.011

    Abstract ( 858 )   PDF (2362KB) ( 1107 )  

    The major geological events during the three Precambrian Eons of the Earth history, i.e., the Hadean, the Archean and the Proterozoic, are summarily described and the Precambrian evolution nature of China continent is roughly depicted. It is desirable to understand the similarity and difference between China and the global, and it is a further highlight of China continent Neoarchean super geological event, and response to the formation and breakup of the Proterozoic Colombia and Rodinia Supercontinents. The Hadean Eon for the earliest period of the Earth history extends from the age of formation of the solar system at 4567 Ma, to the age of Earths oldest dated rock from the Acasta Gneiss Complex, at 4030 Ma. The Hadean detrital zircon has been well preserved from Mt. Narryer and the Jack Hills greenstone belt of Western Australia. Meanwhile at present, rare detrital zircons of Hadean age were analyzed from 7 places in China, those are located at the Neoproterozoic to Paleozoic orogens, not in the cratons. The Archean Eon can be defined as the time of Precambrian history from the first appearance of preserved rocks at the Earths surface (4030 Ma Acasta Gneiss), to the first appearance of widespread glacial rocks, cooler Earth conditions. The oldest dated rock on Earth is a tonalitic gneiss that forms part of the 4.033.94 Ga Acasta gneiss of the northwestern Canada Slave Craton. Supracrustal rocks are locally well preserved in the Isua supracrustal belt in southwestern Greenland. It is worth to point out that the most important event of Archean is the super geological event between 2780 Ma to 2420 Ma. The oldest rocks of the North China Craton (NCC) and also of China are exposed at the Anshan region of Liaoning Province, where about 3.8 Ga tonalitetrondhjemite gneiss and 3.3 Ga supracrustal rocks are recognized. Archean evolution and nature of NCC are quite similar to that of cratons in the world, such as the granitegreenstone belt and highgrade gneiss, tonalitetrondhjemitegranadiritesuite (TTG), older continent crust (a little more than 3.8 Ga) and banded iron formation (BIF) and so on. It is noticed that Archean granitegreenstone belt is widely spreaded at the NCC, but differences with the classical ones in South Africa, Greenland, Canada and western Australia. For example, the age of granitegreenstone belt in NCC is dominantly of the Neoarchean, with smaller size of the belts, less komatiites and higher metamorphism up to amphibolitegranulite facies. Proterozoic Earth is a mature, cooler planet with large, rigid, emergent continental land masses, modernstyle plate tectonics, a supercontinent cycle, and more complex life (eukaryotes). This combination of geological and biological changes took place at about 2420 Ma, near to the time of disappearance of the Hamersleytype BIF and occurrence of the first global glacial event. It is noticed that the Huronian glacial beds and the red strata of the Great Oxidation Event are not recognized in China. The age of Paleoproterozoic Guanmenshan Formation, related to the LomagundieJatuli carbon isotopic excursion, is still uncertain. In addition, Paleoproterozoic phosphorites and the worldwide Shunga event dated to 2.01 Ga, being the source rocks for giant petroleum deposits, are not discovered. However, the assemblybreakup of supercontinentsrelated geological records are well developed in the North China, Yangtze and Tarim Cratons, respectively. The ultrahigh temperature metamorphic rocks, high pressure granulite and Columbia Supercontinet assemblyrelated magmatic association, as well as the arcrelated sedimentary and volcanic strata are exposed. And after 1780 Ma the Mesoproterozoic rifting basins and magmatic activity with disperse of Columbia Supercontinet are widespreaded in the NCC. Meanwhile the Early Neoproterozoic ophiolite, mélange, oceanic arc, subductionrelated accretion complex and continental marginal arcs occurred at the Yangtze and Tarim Cratons, which reflects the Rodinia formationrelated geological events. The rifting basins and a series of magmatism with Rodinia breakup took place since ca. 800 Ma. All of above mentioned provide an objective field laboratory and an outstanding example in studying Precambrian Earth system and mineralization to China and world geoscientists.

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    Revision of the Mesoproterozoic chronostratigraphic subdivision both of North China and Yangtze Cratons and the relevant issues.
    SU Wenbo
    2016, 23(6): 156-185. 
    DOI: 10.13745/j.esf.2016.06.012

    Abstract ( 376 )   PDF (4469KB) ( 789 )  

    Following synthesis of recent advances in geochronological research, the GTS2012 (The Geological Time Scale 2012) Mesoproterozoic (1780850 Ma) chronostratigraphic subdivision of the typical areas both on the North China Craton (NCC) and the Yangtze Craton (YC) of China have been revised thoroughly. It is now know that the early Mesoproterozoic deposits of NCC, between ~1780 Ma and ~1350 Ma, developed initially near the junction of HenanShanxiShaanxi Provinces, and then expended gradually northwards to the Yanshan Mountains and the adjacent areas along the TransNorth China Orogen (TNCO). However, the middle Mesoproterozoic, ~1350 Ma~1100 Ma, are all absent through out the entire craton. In addition to the southwestern Henan (south NCC) and the Yanshan Mountains (north NCC), the late Mesoproterozoic, younger than ~1100 Ma, occurs mainly in the elongated riftrelated basin in the eastern NCC, named the JiaoLiaoXuHuai Sea, in the west Shandong, the southeast Liaoningeast Jilin, the north Jiangsu, and northeast Anhui Provinces. On the other hand, both the early (~1750 Ma~1450 Ma)and the late(<1100 Ma) Mesoproterozoic deposits are developed near the border of Sichuan and Yunnan Provinces, i.e. the KangDian area, along the western margin of YC. The middle Mesoproterozoic, ~1400 Ma~1150 Ma, outcrops mainly in the Shennongjia area, west of Hubei Province, in the northern YC. It means that the Mesoproterozoic successions from the two cratons of China could complement each other to cover the entire proposed GTS2012 Mesoproterozoic Era, 1780 Ma850 Ma. Some relevant fundamental issues emerging from the updated chronostratigraphic framework are discussed in short: (1) Precambrian Stratigraphy: Due to the only one ~1.0 Ga long Rodinian Period proposed for the Mesoproterozoic Era with the same duration in the GTS 2012, a quadripartite intrasubdivision of the Systems (Periods) in this Erathem (Era) has been suggested by the author. All the new Systems (Periods) would be defined by the GSSPs (Global Standard Stratotype Sections and Points) constrained by the sedimentary records of certain LIPsmantle plume events with potentially global influence during this 1.0 Ga. According to the studies of the Phanerozoic Era, such as around the PT boundary and others, these sorts of events should cause significant coupled responses or trigger largescale crises in the multiple spheres of the Mesoproterozoic Earth. It should fit well the definition of the “key causative events” for the use as the Precambrian timescale division under the philosophy of the GTS2012. Covering the entire ~1780 Ma~850 Ma chronostratigraphic framework in the two cratons of China means that, in future research on the suggested quadripartite intrasubdivision of the GTS2012 Mesoproterozoic Erathem (Era), the Chinese researchers would have ample opportunities to define the possible GSSP candidates of each new System (Period), and should contribute uniquely for the Precambrian research; (2) Early evolution of the Eukaryota: With the chronostratigraphic subdivision mentioned above, the horizon of the largescale acanthomorphic acritarch association, i.e. Tappania and others, in the Beidajian Formation of the Ruyang Group at the Shuiyougou section of Yongji, Shanxi Province, southern Zhongtiao Mountains of NCC, should be ~1650 Ma in age. It is the earliest horizon of the unambiguous eukaryotic fossils currently on record around the world. Further, with the distribution elsewhere of Tappaniabearing strata in space and time, it might be inferred that, possibly from ~1650 Ma to ~1450 Ma, i.e. during the initial breakup of the Supercontinent Columbia\Nuna, the NCC should have been neighbored successively with India, Australia, Laurentia and Siberia; (3) Sedimentological and tectonic evolution: The deposition during the GTS2012 Mesoproterozoic Era both in NCC and YC has followed the same threestage style, and the subsidence and uplift areas have alternated in a seesaw pattern, with the time of each turning point, including that of the Jinning Orogen, correlated fairly well. All of these indicate that probably both NCC and YC have been affected by the same tectonic stresses during this Era. Further, combining with the foreland basin setting of the ~1.38 Ga Kbentonitebearing black shale succession in the Xiamaling Formation in Yanshan Mountains, and the Chuariabearing macroalga both in NCC and YC from ~1.1 Ga to ~0.8 Ga, as well as the abundant Grenvillianage detrital zircons in the successions of the eastern NCC during this period, it may be inferred that, the latest around ~1.1 Ga, the eastern NCC might have collided and even assembled with the YangtzeCathaysia blocks along the east or southeast margins of the NCC, and with the microcratons or massifs, including the Silinhot (Inner Mongolia) and the Hutag UulTsagaan Uul (Mongolia), at the northern margin of the NCC. It would have formed a probable hooflike Grenvillian orogen along the eastern NCC connected with Laurentia, Australia, Baltica, Siberia, and other cratons, to witness the terminal assemblage of the Supercontinent Rodinia and its initial breakup.

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    Correlation between the Dagushi Group in the Dahongshan Area and the Shennongjia Group in the Shennongjia Area on the northern margin of the Yangtze Craton: Constraints from zircon UPb ages and LuHf isotopic systematics.
    LI Huaikun,TIAN Hui,ZHOU Hongying,ZHANG Jian,LIU Huan,GENG Jianzhen,YE Lijuan
    2016, 23(6): 186-201. 
    DOI: 10.13745/j.esf.2016.06.013

    Abstract ( 283 )   PDF (2441KB) ( 669 )  

    The Dagushi Group in the Dahongshan Area, at the northern margin of the Yangtze Craton, has long been considered as a Mesoproterozoic sedimentary succession unconformably overlain by the Huashan Group. Owing to lacking of accurate and reliable isotopic ages, the correlation between the Dagushi Group and the Shennongjia Group that also occurred on the northern margin of the Yangtze Craton about 260 km to the west of the Dahongshan Area and other relevant strata in China, still remains as an enigmatic issue. In this study, using Sensitive and High Resolution Ion MicroProbe (SHRIMP) and Laser Ablasion coupled with MultiCollector Inductively Coupled Plasma Mass Spectrometer (LAMCICPMS), we analyzed U-Pb ages and LuHf isotopic compositions for zircons from the tuff beds in the Dagushi and Shennongjia groups, respectively. Two precise zircon UPb ages, 1225±19 Ma and 1239±23 Ma, from the tuff beds in the Luohanling Formation of the Dagushi Group were obtained for the first time. On the other hand, zircons from the two tuff samples of the Luohanling Formation show comparable LuHf isotopic compositions with (176Hf/177Hf)i varying from 0.282172 to 0.282397, corresponding to εHf(t) from 4.9 to 12.0 and TCDM from 1150 Ma to 1943 Ma. The LuHf results of the Dagushi Group are consistent with those of the zircons from a tuff sample from the Yemahe Formation of the Shennongjia Group. Integrating the data obtained in this study with the available regional geological data, we suggest that the Dagushi Group and the Upper Shennongjia Subgroup are coeval sedimentary succesion formed during the breakup of the Columbia Supercontinent, possibly geodynamically related to a super plume.

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    U-Pb zircon ages of tuff beds from the Hongzaoshan Formation of the Quanji Group in the north margin of the Qaidam Basin, NW China, and their geological significances.
    ZHANG Haijun,WANG Xunlian,WANG Xun,ZHOU Hongrui
    2016, 23(6): 202-218. 
    DOI: 10.13745/j.esf.2016.06.014

    Abstract ( 293 )   PDF (2743KB) ( 405 )  

    Located between the North Qaidam Block and the Qilian Orogen, the Quanji Massif (i.e. Oulongbuluke microcontinent) is characterized by a cratonic continental remnant composed of a medium to highgrade metamorphosed basement and an unmetamorphosed cover, representing the typical doublecrust units. The Quanji Group, which unconformably overlies the Palaeoproterozoic Dakendaban Group and underlies the Cambrian Oulongbuluke Group, is the first sedimentary cover of the Quanji Massif. At present, with imprecise constraints, most geologists believe that the Quanji Group is the late Neoproterozoic in age. In this study, as the first time, we report the LAMCICPMS zircon UPb ages of the tuff from the Hongzaoshan Formation of the Quanji Group, which have been divided into Mahuanggou, Kubaimu, Shiyingliang, Hongzaoshan, Heitupo, Hongtiegou, and Zhoujieshan formations, in ascending order. Two LAMCICPMS zircon UPb ages, 1640±15 Ma and 1646±20 Ma, were obtained from the tuff beds in lower part of the carbonatedominated Hongzaoshan Formation at the Quanjishan section, where the Hongzaoshan Formation was defined as a formal lithostratigraphic unit in 1980s. These new ages suggest that the lower Quanji Group, including the Mahuanggou, Kubaimu, Shiyingliang, and Hongzaoshan formations, should be revised into late Paleoproterozoic (Statherian Period) time. Combined with the palaeoweathering crust and disconformity on the top of the Hongzaoshan Formation, and the previous studies on Ediacaran fauna in the Zhoujieshan and glacial diamictite in the Hongzaoshan Formation, it may infer that there should be a huge time gap between the Hongzaoshan Formation and the overlying formations, and the Quanji Group, as a lithostratigraphic unit, should be redefined. Moreover, now it may suggest that the “Quanji Movement”, represented by the unconformity between Dakendaban Group and Quanji Group and conventionally corresponding to the ~850 Ma Jinning Movement in Yangtze Craton, should correlate to the ~1.8 Ga Lüliang Movement in North China Craton (NCC). It seems that, during the Mesoproterozoic time, the Quanji Massif should have more closely tectonic affinity with the NCC than that with the Yangtze Craton.

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    Mesoproterozoic glaucony as a potential mineral proxy for shallow chemocline in the Precambrian ocean.
    TANG Dongjie,SHI Xiaoying,MA Jianbai,SHI Qing
    2016, 23(6): 219-235. 
    DOI: 10.13745/j.esf.2016.06.015

    Abstract ( 337 )   PDF (2954KB) ( 390 )  

    The origin of glaucony in the Phanerozoic sediments has been fairly understood, which generally results from marine authigenesis with slow sedimentary rate, especially in outer shelf environments. In contrast, the origin of glaucony in the Precambrian sediments is still poorly constrained, particularly that why it was commonly deposited in much shallower environments with relatively high sedimentary rate is not fully understood. To address this issue, we carried out an integrated study, including field, petrography, XRD, SEM, EDS, ICPMS investigations on the glaucony and on its host carbonate in stromatolitic reef of the Mesoproterozoic Tieling Formation. Three types of autochthonous glaucony were recognized based on their distribution and substrate porosity, including type 1 (in the most porous belt between stromatolitic column and micritic matrix), type 2 (in less porous matrix) and type 3 (in dense stromatolitic column) glaucony. They were all characterized by constant and high K2O contents (av.>8%), indicating initial high K+ concentration in pore water, and an evolution from type 3 to type 1 glaucony by addition of total Fe2O3 and simultaneous release of Al2O3. These features likely suggest that substrate permeability has controlled the glaucony evolution, and glauconization requires persistent supplement of Fe. Since the stromatolitic carbonates are basically devoid of detrital inputs, Fe may have been largely sourced from seawater. In this case extremely shallow Feredox chemocline was required, which is also supported independently by Ce anomalies in the carbonates. Thus, we proposed that porous substrate, high K+ concentration and suboxic conditions in the Mesoproterozoic shallow seawaters have favored the precipitation and evolution of glaucony.

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    Stratigraphic succession of the Nanhuan Period in the Shennongjia area in western Hubei and its regional correlation.
    GUAN Kaiping,TIAN Li,AN Zhihui,YE Qin,,HU Jun,TONG Jinnan
    2016, 23(6): 236-245. 
    DOI: 10.13745/j.esf.2016.06.016

    Abstract ( 333 )   PDF (1722KB) ( 419 )  

    The Neoproterozoic was a critical time in the history of the earth, because it was the time of the most extreme climate change that yielded numerous glacial deposits over the world. The Neoproterozoic strata in the Three Gorges area, as a representative of the regional succession of western Hubei, has being rigorously studied. However, the Neoproterozoic sequence of the Three Gorges area was incomplete, whereas the corresponding stratigraphic succession was better developed in the neighboring West Shennongjia area. Overlying the Mesoproterozoic Shennongjia Group, the Nanhuan (Crygenian) System at the Gaoqiaohe section in the West Shennongjia area, presented in this paper, is composed of the Liantuo, Gucheng, Datangpo, and Nantuo Formations in ascending order and overlaid by the Sinian (Ediacaran) Doushantuo Formation. The regional correlation with the typical Neoproterozoic stratigraphical sections from the Three Gorges and Changyang areas indicates that the Nanhuan System at the Gaoqiaohe Section is one of the most complete and continuous lithostratigraphic sequences in the western Hubei, and it can be used as a perfect reference for the regional stratigraphical division and correlation and for the study of the extreme climate change through the critical time.

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    High resolution integrated stratigraphy in the age of Earth system science.
    WANG Xunlian,WU Huaichun
    2016, 23(6): 246-252. 
    DOI: 10.13745/j.esf.2016.06.017

    Abstract ( 221 )   PDF (997KB) ( 530 )  

    High resolution chronostratigraphic system is the foundation for the research of Earth system science. High resolution integrated stratigraphy makes an attempt to establish high resolution stratigraphic framework with resolution less than a biozone both for a stratigraphic unit and for the correlation error of a stratigraphic boundary. In the present paper the stratigraphic methods are divided into 3 kinds generally used to establish chronostratigraphic system. They are biostratigraphy, the various subdisciplines of modern stratigraphy, and isotope chronostratigraphy. Their advantages and disadvantages of the 3 kinds of stratigraphic methods are discussed. It is considered that the resolution of any kind of stratigraphic method is limited, and the integrated stratigraphy may provide an effective approach for the high resolution division and high precision correlation of strata. Biostratigraphy is used to establish a believable relative chronostratigraphic framework, the subdisciplines of modern stratigraphy contribute the high resolution division and high precision correlation of strata, and isotope chronostratigraphy gives absolute age of both biostratigraphic boundaries and other kinds of stratigraphic boundaries. The combination of all three (biostratigraphy, modern stratigraphy and isotope chronostratigraphy) commonly constitutes high resolution integrated stratigraphy.

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    Ordovician tectonicpaleogeography in South China and chrono and biostratigraphic division and correlation.
    WANG Xiaofeng
    2016, 23(6): 253-267. 
    DOI: 10.13745/j.esf.2016.06.018

    Abstract ( 331 )   PDF (3087KB) ( 551 )  

    Restudy of Ordovician lithological facies, biota and tectonic combination characteristic in South China, three different types of tectonicpaleogeographic regions have been recognized, namely the Yangzi shallow sea carbonate platform facies, the Jiangnan and South Qinling shelfslope transitional facies, and the Cathaysia continental marginal island arc or basin facies. The former two belong to the Yangtze block. The latter, so called the Zhujiang (Pearl River) basin facies of the Huanan massif, seems to be of the Cathaysia block, rather than the South China block on the basis of the characteristics of Ordovician sedimentary, biological facies and water flow direction of NW320° shown by flute cast structure. The Hainan Island as a drift terrain in the Ordovician might belong to the shelf area of platform margin of the IndoChina block. Ordovician chrono and biostratigraphic division and correlation study indicated that the Xiaoyangqiao CambrianOrdovician boundary section near Dayangcha, Baishan (formerly Hunjiang), Jilin, China devoloped a complete representative conodont and graptolite successions and the FAD of the conodont species Cordylodus intermedius of the section might be applied instead of the FAD of the controversial and rare Iapetognathus fluctivagus as boundary biomarker for determining global Cambrian and Ordovician System. The NijiangkouNanba section near Yiyang of Hunan appears a complete Upper Tremadocian to Lower Floian graptolite sequence. Recommended here the Yiyang stage, replacing the “Daobaowan stage”, as the Ordovician regional chronostratigraphic units in China. Its boundary with underlying Tremadocian stage is assigned between the Hunnegraptus copiosus and Tetragraptus approximatus graptolite zones and easy to correlate to that of the Diababrottet GSSP in Sweden. Systematic collection and studies to the conodontbearing carbonate strata wellexposed at the Huanghuachang, Fenxiang, Chenjiahe and Puxihe sections near Yichang City, Hubei and Maocaopu section, Cili, Hunan suggested that 8 conodont biozones can be recognized in ascending order in the Dawan Formation, i.e. Upper Oepikodus communis, Oepikodus evae (s.s.), Periodon flabellum, Microzarkodina russica, Baltoniodus triangularis, Baltoniodus navis, B. norrlandicus, Lenodus antivariabilis Biozones, their correlative relationship with relevant graptolite biozone are discussed. The findings of conodont Protopederodus liripipus in 23 m limestone above the base of the Baota (Pagoda) Formation of the Huanghuachang and Puxihe sections and the relevant carbon isotopic excursion suggest that the lower boundary of the Upper Ordovician Katian Stage is broadly filled in the lower Pagoda Formation on the Yangtze Craton platform, being equivalent or close to the base of the Hamarodus? europaeus Biozone. New Highresolution Ion Microprobe (SHRIMP II) zircon UPb dating indicates that the age of the bentonite interbeds of 20 cm below the base of the Dicellograptus complexus Biozone in the lowest Wufeng Formation in Yichang area might be 448.6±4.8 Ma, and 446.5±2.1 Ma for the bentonite layers, 30 cm below the top of the Paraorthograptus pacificus Biozone, indicating that the Wufeng Formation in Yichang area endured about 5.4 Ma of sedimentation time.

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    Chemostratigraphy and cyclostratigraphy of the Ordovician Liangjiashan section from Shimenzhai of Qinhuangdao in North China.
    MA Kunyuan, LI Ruochen, GONG Yiming.
    2016, 23(6): 268-286. 
    DOI: 10.13745/j.esf.2016.06.019

    Abstract ( 554 )   PDF (3319KB) ( 369 )  

    According to the chemostratigraphy and lithostratigraphy of the Ordovician Liangjiashan section in Qinhuangdao of North China, the Liangjiashan Formation was divided into the lower, middle and upper members. We chose the Fe/Ca and Ti/Ca ratios as the paleoclimate proxies and carried out the timeseries analysis. The timeseries analysis of the Fe/Ca and Ti/Ca data was performed by means of Multi Taper Method (MTM) and Fourier Transform (FT), from which two obvious cycles were identified: long eccentricity (E) 405 ka and short eccentricity (e) 90 ka. The float point time scale (based on the long eccentricity cycle) indicates that the duration of the Liangjiashan Formation is 6.2 Ma, the mean sediment accumulation rate in the Liangjiashan Formation is 14.68 m/Ma, and the sedimentation rate of the lower member and the middleupper members are 12.00 m/Ma and 19.55 m/Ma respectively; the sedimentation rate in the Majiagou Formation is 18.00 m/Ma. The Ordovician radiation seemed to result in the changing of carbonate production from marldominated to biodetritusdominated, which accelerated the sediment accumulation rate during the transition from the lower to the middleupper members of the Liangjiashan Formation. Our cyclostratigraphical data show that the Ordovician radiation may be regulated by the earth's climate changes caused by the orbit cycle variations.

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    Radiolarian cherts from the Luang Prabang tectonic zone in NW Laos and their tectonic implications.
    QIAN Xin,FENG Qinglai,WANG Yuejun
    2016, 23(6): 287-298. 
    DOI: 10.13745/j.esf.2016.06.020

    Abstract ( 252 )   PDF (3387KB) ( 323 )  

    Radiolarian cherts from the Luang Prabang tectonic zone contain radiolarian Entactinia vulgaris Won, Entactinosphaera palimpola Foreman and Belowea variabilis (Ormiston et Lane)from the Early Carboniferous Period, as it was first reported in Laos. The samples have high SiO2 content(95.29%98.17%). Most samples exhibit similar REE patterns, some show convex REE patterns with slight enrichment in MREEs. All samples have negative Ce anomalies(Ce/Ce*=0.640.74), whereas some display negative Eu anomalies(Eu/Eu*=0.580.68). The Y/Ho ratios range from 31.05 to 40.96, resembling those of Sasayama MiddleLate Permian pelagic cherts in Japan. Geochemical characteristics indicate an origination of the nonhydrothermal pelagic cherts with the involvement of acidic volcanoclastic rocks. These results prove the existence of an open Carboniferous backarc basin between the Simao Block and the Indochina Block.

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    Response of early Permian silisiclastic depositional system to the advance of Gondwana glaciation in Southwestern Guizhou.
    WU Siqin,YAN Jiaxin,LIU Ke,YAN Yajuan
    2016, 23(6): 299-311. 
    DOI: 10.13745/j.esf.2016.06.021

    Abstract ( 298 )   PDF (3102KB) ( 331 )  

    Silisiclastics strata underlying the Permian Qixia Formation in Southwestern and Southern Guizhou were commonly supposed to be accumulated while the waxing of the PermoCarboniferous glaciation. However recent works indicated that the Gondwana glaciation consists of eight discontinuous glacial advances. Thus, it is of great significance to recover the depositional environment and process of this silisiclastic succession and to correlate its evolution with the Gondwana glaciation. Present study delineates the spatial variation of the thickness and the sandstone/mudstone ratio of the succession based on literature survey, and describes depositional system at the wellexposed Longyin section. Results demonstrate that the Shazitang Formation is mainly shallow water carbonate deposition, the Longyin Formation and the Baomoshan Formation is dominated by shelf and delta facies, and the Liangshan Formation is composed of near shore clastic deposits in ascending order. The Lower Permian shelf mudstone of the southwestern Guizhou was formed during the rapid sealevel rise correlating with glacial retreating, and the delta depositional system deposited in the late highstand of sealevel fluctuation, rather than the lowstand during the expansion of the Gondwana glaciation. In conclusion, the wax and wane of the Gondwana glaciation is the dominant controlling factor for the architectural pattern of early Permian strata at Longyin section, Southwestern Guizhou.

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    Jurassic-Cretaceous boundary and its terrestrial issue in Northern China.
    WAN Xiaoqiao,GAO Lianfeng,QIN Zuohuan,CUI Can1,LI Wei,XI Dangpeng
    2016, 23(6): 312-322. 
    DOI: 10.13745/j.esf.2016.06.022

    Abstract ( 463 )   PDF (1709KB) ( 646 )  

    The Jurassic/Cretaceous is the only Phanerozoic boundary that does not yet have an accepted global boundary definition. In contrast to most geological systems, there are nearly no “global events” within the uppermost Jurassic and lowermost Cretaceous. It has been difficult to find any significant widespread biostratigraphic, geochemical or other markers for interregional correlation within this interval. The ammonite definition for the base of the Cretaceous appears to fall within the middle of relatively long ammonite zones. The current markers tend to integrate regional calpionellid zones, calcareous nannofossil datums, ammonite zonations, and magnetostratigraphy. The J/K boundary is at the base of Calpionella alpina zone and FAD of Nannoconus steinmannii minor and N.kamptneri minor. It is in the Chron M19n.2n and of 145 Ma age. The international stratigraphical division and correlation are based on marine standard. The Jurassic and Cretaceous strata in northern China are mostly of terrestrial origin. It appears a difficulty to define the boundary. In the previous biostratigraphic work, the J/K boundary was referred to a higher position of much younger age, which caused a big controversy between local biostratigraphy and international age. The pronounced provincialism of terrestrial fauna and flora obstructs global correlation. The solution of persistent debates on the J/K boundary in China should be the integrated stratigraphic markers which might provide the most useful global correlation. Owing to the obscure of terrestrial fossil evidences to indicate the boundary, the macro biotic evolution is suggested as a potential workable J/K boundary indicator. The Yanliao Biota and Jehol Biota are two big fossil groups representing Jurassic and Cretaceous respectively. If it is the case, the transition beds of two biotas would be down to the Tuchengzi Formation. The boundary age could alternatively be 139 Ma on the top or 145 Ma in the middle of the formation. Only accurate indicators or markers would be obtained from the Tuchengzi Formation and/or GSSP being accepted, the J/K boundary in China tends to be completely located.

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