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Pioneer organisms after F-F mass extinction in Dushan region,Guizhou Province,and their significance in establishing new ecosystem

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Science China earth sciences 2006年第5期49卷 449-460页

作者： wang Yue1, 2. wang {2.1 & SHI Xiaoying1 1. School of earth sciences and resources, China university of geosciences, beijing 100083, China 2. School of resources and Environment, Guizhou university, Guiyang 550003, China School of earth sciences and {2. China University of Geosciences Beijing China School of resources and Environment Guizhou University Guiyang China

After mass extinctions, most areas became “ecologically barren areas” lacking or even without ecosystem over an extensive region. Studying the pioneer organisms and the reconstruction process of a new ecosystem in the “ecologically barren area” is very important for revealing the evo- lution after bio-mass extinctions. In the Dushan region, Guizhou Province, China, the trace fossils appeared and flourished evidently earlier than body fossils after Frasnian-Famennian (F-F) mass extinction. The pioneer organisms and pathfinders in the “ecologically barren areas” are the trace-makers that are deposit-feeders with relatively simple structure and conformation on or near the deposit surface. The trace-makers have undergone an evolutionary process that their trace structures changed from simple to complex, and their living and moving areas and spaces enlarged from linear to planar and then to three-dimension spaces. Those characters show that the ability of the trace-makers to deposits and their efficiency of looking for food have been enhanced gradually and that those trace-makers constructed gradually a base for the new ecosystem. This process is similar to that of the trace fossils near the Precambrian-Cambrian boundary. In the Dushan area, only the recovery intervals have been identified for the Famennian body fossils, with no eminent radiation interval recognizable due to the Devonian-Carboniferous (C-D) mass ex- tinction. However, both the recovery and radiation intervals may be clearly recognized in the Famen- nian trace fossils based on their conformation and diversity. The evolution and diversification of the trace fossils in the “ecologically barren area” is considered to have played a role of necessary foun- dation for the recovery of body fossils in the ecological chain. With the gradual disappearance of the unfavourable environment factors resulting in the F-F mass extinction, a new ecosystem was reconstructed in the “ecologically barren area” through a three-

关键词： pioneer organisms, reconstruction of ecosystem, trace fossils, F-F mass extinction, Later Devonian, Dushan region, Guizhou Province, China.

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The species diversity of fusulinaceans and high-frequency sea-level changes in the Carboniferous-Permian boundary section at Xikou, Zhen'an County,Shaanxi Province, China

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Science China earth sciences 2006年第7期49卷 673-683页

作者： ZHANG Haijun1, wang xunlian2. DING Lin1, XIA Guoying3 & wang Lei2.1. Institute of Tibetan Plateau Research, Chinese Academy of sciences, beijing 100085, China 2. faculty of earth sciences and mineral resources, China university of geosciences,{12., China 3. Tianjin Institute of Geology and mineral resources, Tianjin 300170, China Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing China faculty of earth {2. and mineral resources China University of Geosciences Beijing China Tianjin Institute of Geology and mineral resources Tianjin China

The study on the interrelation between sea-level changes and biodiversity with its evolu-tion has great significance for understanding the impact of global changes on organic evolution and exploring the inherent laws of life-environment coevolution in geological history. In this paper, the stratigraphic distribution of fusulinacean fauna in the Carboniferous-Permian boundary section at Xikou, Zhen’an County, Shaanxi Province, is analyzed quantitatively, and the relationship between the species diversity of fusulinaceans and relative sea-level changes is discussed. As a whole, the spe-cies numbers of fusulinacean fauna experience a rapid increase and an obvious decline in Xikou, Zhen’an County, from the Late Carboniferous to the Early Permian. There is a significant increase in species diversity around the Carboniferous-Permian boundary, which is one of the biggest bio-events of the fusulinacean fauna, and represents the radiation of Pseudoschwagerininae subfamily in the studied area. Integrated fusulinacean species diversity into sequence stratigraphic framework, de-tailed study suggests that the species diversity of the fusulinaceans is closely related to its relative stratigraphic location, and is essentially controlled by the sea-level changes, especially by the high-frequency sea-level changes. Generally, the species diversity of fusulinaceans is low, and the number of first and last appearance datum is small in the lower unit of high-frequency depositional cycle formed during the quick rise of the sea level; whereas the species diversity of fusulinaceans is high, and the number of first and last appearance datum is large in the upper unit of high-frequency cycle formed during the slow fall of the sea level. Within the third-order depositional sequence, the species diversity of the fusulinaceans at the first flooding surfaces and the maximum flooding surfaces is low, and it increases upward. The fusulinacean species diversity is low within the transgressive syst

关键词： fusulinaceans, species diversity, high-frequency cyclothem, sequence stratigraphy, sea-level changes, Carboniferous-Permian boundary, Zhen'an, Shaanxi.

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Criteria for defining and recognizing the various orders of sequences in outcrop sequence stratigraphy

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Science China earth sciences 2004年第7期47卷 618-629页

作者： wang xunlian faculty of earth sciences and mineral resources, China university of {2., beijing 100083, China State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of sciences, Nanjing 2.0008, China faculty of earth {2. and mineral resources China University of Geosciences Beijing China State Key Laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences Nanjing China

The regional distribution in different depositional facies belts is here regarded as an important criterion for defining and recognizing the various orders of sequences. The third-order sequence is possibly global in nature, which may be discerned in different depositional facies belts in one continental margin and can be correlated over long distances, sometimes even worldwide. Commonly, correlation of subsequence (fourth-order sequence with time interval of 0.51.5 Ma) is difficult in different facies belts, although some of them may also be worldwide in distribution. A subsequence should be able to discern and correlate within at least one facies belt. The higher-order sequences, including microsequence (fifth-order sequence) and minisequence (sixth-order sequence), are regional or local in distribution. They may reflect the longer and shorter Milankovitch cycles respectively. Sequence and subsequence are usually recognizable in different facies belts, while microsequence and minisequence may be distinguished only in shallow marine deposits, but not in slope and basin facies deposits. A brief discussion is made on the essential conditions for correct identification of sequences, useful methods of study, and problems meriting special attention in outcrop sequence stratigraphy.

关键词： outcrop sequence stratigraphy, facies belt, sequence, subsequence, microsequence, minisequence, meter-scale cyclothem, Milankovitch cycle.

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Problems of Sequence Stratigraphy in China

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Journal of earth Science 2000年第3期19卷 10-20页

作者： wang Hongzhen faculty of {2. sciences and mineral resources, China university of geosciences, beijing 100083, China

A comprehensive study of outcrop sequence stratigraphy in China began in the early 1990s. The investigated strata range from Mesoproterozoic to Quaternary and the studied areas cover the three platforms and margins, the Southern Himalayas and the East China and South China seas. Problems of general concern in the sequence stratigraphy of China are discussed. These are: the hierarchy for sequence stratigraphy, the third order Sequence and eustasy, the chronostratigraphic boundaries and GSSP, and the International Stratigraphic Chart and the sequence chronostratigraphy of China. The average time interval of Mesosequence (2.-40 Ma) and of the Sequence (2.5 Ma) is suggested and the minor sequences below the Sequence are discussed. The time interval of the Sequence shows no evident decrease with time, but several epochs with remarkable short intervals occur in the Phanerozoic, which may represent a planetary behavior denoting the special development stages in earth’s evolution. Sea level change curves are given separately for the three platforms and the different regions. The Global Stratotype Section and Point (GSSP) concept and practice are discussed, and a comparison between the first appearance point of biozone and the first flooding surface in the Sequence is made for designation of the chronostratigraphic boundary. It is suggested that the chronostratigraphic boundaries might be set at the first flooding surface in the Sequence for easy recognition. The idea of sequence chronostratigraphy is recommended, and a comparison between the International Stratigraphic Chart and the sequence chronostratigraphy of China is made. The close relation between chronostratigraphy and sequence stratigraphy makes it possible for sequence stratigraphy to improve chronostratigraphic research. It is pointed out that multidisciplinary study in chronostratigraphy is necessary and should be promising and profitable.

关键词： sequence stratigraphy chronostratigraphy GSSP China.

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Experimental remolding on the caprock's 3D strain field of the Indosinian-Yanshanian epoch in Tongling deposit concentrating area

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Science China earth sciences 2005年第7期48卷 863-874页

作者： DENG Jun1,HUANG Dinghua2.wang Qingfei1,WAN Li1,SUN Zhongshi3,YANG Liqiang1 & GAO Bangfei1 1. State Key Laboratory of Geological Processes and mineral {2.,China university of geosciences,beijing 100083,China 2. faculty of earth sciences,China university of geosciences,Wuhan 430074,China 3. Department of earth sciences,Jilin university,Changchun 130061,China State Key Laboratory of Geological Processes and mineral resources China University of Geosciences Beijing 100083 China faculty of earth {2. China University of Geosciences Wuhan 430074 China Department of earth sciences Jilin University Changchun 130061 China

Based on field observations and rheology analysis, we perform one analogue experiment and remold the 3D structural frame of Tongling deposit concentrating area firstly. Then we disassemble and dialyze the 3D structures of the model using the methods of "slicing" and "stripping". A series of sliced planes vertical to the fold hinges show similar landscapes of that in the drill hole profiles. Meanwhile, layer stripping analysis indicates that the deformation features of each layer in the model are qualitatively analogical to those obtained from field observations. Through contrasting the 3D structure between the experimental model and the field phenomena, we verify the following 3D deformation features of the caprock in this area: (1) the Tongling area mainly consists of three series of NE S-typed fold groups; (2. in the uniform stress field, the incoherent folds universally develop in different positions, along different axes as well as in different strata; (3) the faults propagate upward which are mostly inter-bedded detachment faults, while the fold amplitudes decrease while going deeper; and (4) the folds and cleavages are highly developed in the Silurian System indicating that the deformation effect of the Indosin-ian-Yanshanian structural layer terminates at this layer, which suggests that the Silurian System is the crucial layer for the inversion between brittle and plastic deformation domains and the underlying strata are subject to the control of another deformation system with distinct properties.

关键词： Tongling deposit concentrating area Indosinian-Yanshanian epoch 3D structural frame of the caprock analogue experiment slicing and stripping analysis structural model.

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Transport network and flow mechanism of shallow ore-bearing magma in Tongling ore cluster area

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Science China earth sciences 2006年第4期49卷 397-407页

作者： DENG Jun1,2. wang Qingfei1,2., HUANG Dinghua3 , WAN Li4, YANG Liqiang1,2.& GAO Bangfei1,2.1. State Key Laboratory of Geological Processes and mineral {2., China university of geosciences, beijing 100083, China 2. Key Laboratory of Lithosphere Tectonics and Lithoprobing Technology of Ministry of Education, China university of Geo- sciences, beijing 100083, China 3. faculty of earth sciences, China university of geosciences, Wuhan 430074, China 4. School of Mathematics and Information Science, Guangzhou university, Guangzhou 510405, China State Key Laboratory of Geological Processes and mineral resources China University of Geosciences Beijing China Key Laboratory of Lithosphere Tectonics and Lithoprobing Technology of Ministry of Education China University of Geosciences Beijing China faculty of earth {2. China University of Geosciences Wuhan China School of Mathematics and Information Science Guangzhou University Guangzhou China

Abundant studies revealed that shallow intrusions of the Yanshanian epoch resulted in the mass mineralization of the Tongling region. Various evidences showed there existed a concealed magma chamber at ?10 km depth in the middle part of this region during Yanshanian epoch, from which the ore-forming magma was generated and then transported to the superficial layer. Yet the transport network and flow mechanism of the shallow ore-bearing magma, the key problem associ- ated with ore-forming process, was relatively little focused on. Integrate analysis of structural me- chanics, statistical fractal and geological facts suggested that NE trending high-angle fold-related thrust faults and the tessellated basement ones served as the main pathways for the shallow magma’s transporting, moreover, the saddle void spaces among adjacent strata in the folds upon this fault system provided the place for magma’s emplacement. So the folds in the upper part and faults in the lower part of the upper crust constituted the fluid’s transport and emplacement network. During the deformation of geologic body with multi-layer structure, the layers in the upper part tended to fold when received the jacking stress from the lower part, while the lower one inclined to fault undergoing loads of the upper part. And the producing probability of this structure assemblage was highly in- creased in the condition, such as in the Tongling area, that the mechanic rigidity of the lower layers was stronger than that of the upper ones. For the pre-existence of fluid-conducting network, the top magma with high volatile in the magma chamber transported rapidly to the superficial layer in dyking pattern, located in the void spaces of folds, filled and reconstructed them. The sudden drop of pres- sure caused the fluid unmixing from the magma and mass ore-forming elements concentration. Pulse activity of the dyking may be the principal reason why magmatic bodies in the Tongling area were spatially-temporally con

关键词： Tongling, structural network, magma intrusion, fractal, dyke.

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Ore-forming Response to Syndepositional Submarine Volcanism in Langshan-Zhaertai Mesoproterozoic SEDEX Ore Belt, Inner Mongolia, China

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Journal of earth Science 2000年第3期19卷 108-113页

作者： Peng Runmin Zhai Yusheng Deng Jun Xiao Rongge wang Jianping faculty of {2. sciences and mineral resources, China university of geosciences, beijing 100083, China

Ore forming process of the Dongshengmiao, Huogeqi, Tanyaokou and Jiashengpan deposits in Langshan Zhaertai Mesoproterozoic SEDEX metallogenic belt is closely related to the syndepositional volcanic activities based on the following facts: (1) The Sm Nd isochron age of the basic volcanic rocks varies from 1 491 Ma to 1 82. Ma (more than or close to the model age of the lead isotope of all sulfide minerals) in these deposits, with ε (Nd, t ) =(3.48-6.40)±0.80, whose REE composition is enriched in LREE and depleted in HREE, indicating that these volcanic rocks were derived from the mantle or lower crust. (2. The REE composition of some Pb Zn Py ores is also enriched in LREE and depleted in HREE. The chondrite normalized REE patterns are similar to those of the basic volcanic rocks. (3) In the lead isotope composition diagram of Doe and Zartman, most of sphalerite, galena, pyrite, pyrrhotite and chalcopyrite are plotted on both sides of the line for the mantle or between the lines for the mantle and lower crust. (4) Cobalt content of some pyrites is much higher than their nickel content ( w (Co)/ w (Ni)= 11.91- 12.19). (5) Some volcanic blocks and debrises have been picked out from some pyrite and pyrrhotite ores. (6) All Zn Pb Cu Fe sulfide orebodies in these deposits occur in the strata overlying the metamorphic volcanic rocks in the only second ore bearing formation. The Jiashengpan deposit lacks in syndepositional volcanic rocks in the host succession, only Pb and Zn occur without Cu, but the Dongshengmiao, Tanyaokou and Huogeqi deposits with syndepositonal volcanic rocks in the host succession contain Cu, indicating the relatively high ore forming temperatures, besides Pb and Zn. The syndepositional volcanic eruption directly supplied some ore forming metals and resulted in the secular geothermal anomaly favorable for the circulation of the submarine convective hydrothermal system, and in the precipitation of deep mineralizing fluids exh

关键词： volcanic activities ore forming response SEDEX deposit Mesoproterozoic Inner Mongolia.

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Lead-Zinc-Silver Metallogenic Prediction Based on Weights of Evidence Approach:A case Study in Tuotuohe Region,Qinghai,China

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地学前缘 2009年第S1期16卷 177-178页

作者： Yan Sun~(1,2,3),xunlian wang~3,Jianping Chen~(1,2,3),Qian wang~(1,2,3) 1.Institute of High and New Techniques Applied to Land resources,China university of geosciences(beijing),beijing 100083, China. 2.beijing Key Laboratory of Development and Research for Land resources Information,China university of geosciences (beijing),beijing 100083,China 3.School of earth sciences and resources,China university of geosciences(beijing){2.},China

Tuotuo River region(E91°-E93°,N33°-N 35°) is located in southwest Qinghai Province,*** lies in one of the most important metallogenic belts in China—Northwest Sanjiang Metallogenic Belt,due to which Tuotuo River region can be of very high metal mineral potential not only in Qinghai Province but also *** this research,multisource data sets including geological,geochemical,geophysical, and remotely sensed images were integrated for mineral potential analysis with GIS *** the guidance of regional metallogenic features and deposit-forming geologic anomaly theories,evidential layers were obtained from these sets,which

关键词： Sanjiang metallogenic belt Tuotuo River lead-zinc-silver GIS Weights of Evidence minerogenic prediction

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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 {2. sciences and mineral 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 {2. 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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Shear Alteration, Mass Transfer and Gold mineralization: An Example from Jiaodong Ore Deposit Concentrating Area, Shandong, China

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Journal of earth Science 2000年第3期19卷 87-93页

作者： Deng Jun Zhai Yusheng wang Jianping faculty of {2. sciences and mineral resources, China university of geosciences, beijing 100083, China Yang Liqiang Institute of Geophysics, Chinese Academy of sciences, beijing 100101, China Fang Yun faculty of

Taking the gold ore deposit concentrating area of Jiaodong area in Shandong, China for an example, based on geological analysis, and applying Gresens’ equation, Grant’s isocon diagram and O’hara microelement calculation method, a thorough study on shear alteration, mass transfer and gold mineralization was carried out. The authors also made mathematic simulation and geochemical analysis. The work reveals temporal spatial changing regularities of temperature field and velocity field of fluids, and also reveals fluid transport chemical reaction coupling metallogenic dynamics of the Jiaojia gold ore concentrating area. During shear alteration process of the Jiaodong gold ore concentrating area, all kinds of components transferred with different amounts, fluid rock ratio was rather high and volume strain was of dilation type. Fast flow of ore forming fluid favors the occurrence of mixed fluid. Shear fractured zones are places where there was strong transportation reaction coupling mineralization. Ore bodies were located in dilation space of shear structure where there was the greatest fluid flux. After the emplacement of the rock body, a convex heat field was formed around the rock body. It is one of the main metallogenic forces. The major reason for mineralization is the mobilization, migration and enrichment of ore forming elements induced by shear compressive extensional tectonism. Inclusion gold dominant low grade ores were formed in the early ore forming stage, while high grade ores, which contained fissure gold and polymetallic veinlets, were formed in late ore forming stage.

关键词： shear alteration mass transfer transportation reaction coupling ore forming process.

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