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Discovery and analysis of ultra-micro grinding grain texture in slipping lamellae of ductile-brittle zone

Science china earth sciences 2004年第3期47卷 265-271页

作者： GE Heping1, SUN Yan1, LU Xiancai1, ZHU Wenbin1, GUO Jichun1, LIU Deliang2 & Chi-yuen Wang3.1. Department of earth sciences, Nanjing university, State Key Laboratory of Mineral Deposit, Nanjing 210093. {3. 2. Department of earth and Space sciences, university of Science and Technology of {3., Hefei 23.026, {3. 3. Department of Geology and Geophysics, university of California, Berkeley, CA 94720, USA Nanjing Univ Dept Earth Sci State Key Lab Mineral Deposit Nanjing 210093 Peoples R China Univ Sci & Technol china Dept Earth & Space Sci Hefei 230026 Peoples R China Univ Calif Berkeley Dept Geol & Geophys Berkeley CA 94720 USA

Based on the observation of the deep bore cores sampled from the State of Cali-fornia, USA, preferred arranged particulate concentration belts were found in the ultra-slipping lamellae. And the same phenomenon was found again later in the bore cores from the petroleum basin in the Northern Shaanxi Province. It may be the product of the dynamic processes involv-ing tumbling, grinding and compresso-shearing functions, so the spherical particulates with ul-tra-size of nm and mm are called grinding grain. The formation of the grinding grains is related with the ductile-brittle deformation, the lateral pressure of the slipping, and the very low grade of dynamic metamorphism of the rocks. Based on the systematic analysis, it is indicated that some elements like Nb and Ta are enriched in the grinding grains in the granitic rocks because of the chemical differentiation, and that the slipping lamellae bearing grinding grains in mudstone with smear efficiency prove a perfect seal for oil and gas reservoirs. Meanwhile, the paper provides bases for the studies on the fast stick-slip movement and shear paradigm.

关键词： slipping lamellae, grinding grain texture, ductile-brittle deformation, smear efficiency.

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Quaternary marine transgressions in eastern china

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Journal of Palaeogeography 2012年第2期1卷 105-125页

作者： Lin Jingxing1, 3. Dai Luping2, 3.1. Institute of Geology, Chinese Academy of Geological sciences, Beijing 10003., china 2. Key Laboratory of Marine Ecology and Environmental sciences, Institute of Oceanology, Chinese Academy of sciences, Qingdao 266071, china 3. College of earth Science, Graduate university of Chinese Academy of sciences, Beijing 100049, china Institute of Geology Chinese Academy of Geological Sciences Beijing 100037 China College of earth Science Graduate University of Chinese Academy of Sciences Beijing 100049 China Key Laboratory of Marine Ecology and Environmental sciences Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China

Based on the data from 117 holes (9151 samples) and the research on ecology and palaeoecology of Foraminifera combined with that on Ostracoda, diatoms, pollen and spores, eight marine transgressions have been recognized in the great plain regions through the Quaternary sequences and two marine transgressions have been found since the Late Pleistocene in the coastal plain (bedrock coast) areas. In the North china Plain, these are in ascending order:the Bohai transgression in the Early Pleistocene, the Haixing and Huanghua transgressions in the Middle Pleistocene, the Baiyangdian and Cangzhou transgressions in the Late Pleistocene, and the Tianjin transgression in the Holocene. In the Yangtze River Delta region the Rugao and Zhoupu transgressions occurred in the Early Pleistocene, the Shanghai, Jiading, and Wangdian transgressions in the Middle Pleistocene, the Jiangyin and Ge Hu transgressions in the Late Pleistocene, and the Zhenjiang transgression in the Holocene. In the coastal plain (bedrock coast) areas of North china, the Cangzhou transgression was recorded in the Late Pleistocene and the Tianjin transgression in the Holocene, whereas in South china the Fuzhou transgression took place in the Late Pleistocene and the Changle transgression in the Holocene. The transgressions correspond to warm periods and regressions to cold periods. The younger transgressions were not only of shorter duration, but also of larger magnitude. These findings point to the existence of four flood event strata since the Middle Pleistocene: two in the late Middle Pleistocene and another two in the Late Pleistocene.

关键词： Quaternary marine transgressions palaeoclimate eastern china

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Extensional Tectonic Framework of Post High and Ultrahigh Pressure Metamorphism in Dabieshan,china

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Journal of earth Science 1998年第1期17卷 3-7页

作者： Zhong Zengqiu Suo Shutian You Zhendong faculty of earth sciences, {3. university of Geosciences, wuhan 4.0074

The most prominent feature of the extensional tectonic framework of post high pressure (HP) and ultrahigh pressure (UHP) metamorphism in Dabieshan is the development of the multi layered extension detachment zones surrounding the core of the Luotian dome, and the separation of the UHP, HP and epidote blueschist units by the detachment zones, which form the vertically stacking sheet like slices of the HP and UHP metamorphic rocks. From the core outwards, exist the HP and UHP rock barren Dabie complex, UHP unit, HP unit and epidote blueschist unit. The extension tectonics of post HP and UHP metamorphic event constrain the distribution and present configuration of the HP and UHP metamorphic rocks, and the extensional tectonic framework bears some similarities to the Cordillera metamorphic core complex. It is suggested that partial melting happened in the Dabie gneiss complex (DGC) and UHP unit contemporaneously with the extrusion of UHP metamorphic rocks into the lower-middle crust. The formation and emplacement of the migmatite and granites are the response to the change in thermal state, facilitating the transfer from the compressive regime to extensional regime in the crust. The large scale crustal extension and uplift and the accompanying anatexis in Dabieshan are probably related to the delamination and magmatic underplating in the mantle and the lower crust.

关键词： high and ultrahigh pressure metamorphic rocks post collision extension tectonics Dabieshan.

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Phytolith Records in Vermicular Red earth:Implications for Bioclimatic Variationsduring Pleistocene

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Journal of china university of Geosciences 2001年第1期12卷 27-30页

作者： Gu Yansheng Zhuo Ying Zhang Zejun faculty of earth sciences, {3. university of Geosciences, wuhan 4.0074 faculty of earth sciences China University of Geosciences

Phytolith analysis is employed in bioclimatic research into vermicular red earth, especially into its form, assemblage and zonation. The phytolith assemblage is divided into 10 zones. The statistics and main factor analysis of phytolith show that the obtained main factor load curves could suggest a climate change. Combined with phytolith assemblage feature, the bioclimatic variation of vermicular red earth during its formation stage, consisting of 5 arid-cold stages, 4 warm-humid stages and 2 mild stages, is reconstructed in detail. The research results indicate that phytolith records are ideal paleoclimatic signals in vermicular red earth, and that abundant information on environmental evolution can be located.

关键词： phytolith records vermicular red earth bioclimatic variation.

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Relic UHP Structures in Dabie-Sulu Region, china: Structural Expression and Geodynamic Significance

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Journal of earth Science 2000年第3期19卷 40-46页

作者： Suo Shutian Zhong Zengqiu You Zhendong Zhou Hanwen faculty of earth sciences, {3. university of Geosciences, wuhan 4.0074, {3.

The present day observed tectonic framework of ultrahigh pressure (UHP) metamorphic belt in the Dabie Sulu region was dominantly formed by an extensional process at 200-170 Ma, under amphibolite facies conditions, following the Triassic collision between the Sino Korean and Yangtze cratons. UHP relic structures, including massive eclogites with a weak foliation, UHP shear zones and A type folds, that are preserved in less retrograde metamorphism and deformation overprinted eclogite lenses can be recognized using the tectonic analysis. Examples are drawn from the Chengmagang area and Hejiawan area, Hubei; Bixiling area, Anhui, and Donghai area, northern Jiangsu. A speculative kinematic model is proposed for the collision between the cratons based on the UHP relic structures studied, in combination with the data of petrography, geochronology and P T path of UHP metamorphic rocks in the studied region which were reported in literature. It is stressed that only the early UHP relic structures, particularly, regionally consistent foliation and stretching lineations, record and reflect the formation of the UHP metamorphic rocks, and the relative dynamic and kinematic process related to the Triassic NNE directed oblique collision between the Sino Korean and Yangtze cratons.

关键词： UHP relic structure extensional process compressional regime stretching lineation Dabie Sulu region.

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Impacts of permafrost changes on alpine ecosystem in Qinghai-Tibet Plateau

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Science china earth sciences 2006年第11期49卷 1156-1169页

作者： WANG Genxu1,3., LI Yuanshou2 , WU Qingbai2 & WANG Yibo3.1. Institute of Mountain Hazards and Environment, Chinese Academy of sciences, Chengdu 610041, china 2. Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of sciences, Lanzhou 73.000, china 3. Resource and Environment School, Lanzhou university, Lanzhou 73.000, china 1. Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 China 3. Resource and Environment School Lanzhou University Lanzhou 730000 China 2. Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China

Alpine cold ecosystem with permafrost environment is quite sensitive to climatic changes and the changes in permafrost can significantly affect the alpine ecosystem. The vegetation coverage, grassland biomass and soil nutrient and texture are selected to indicate the regime of alpine cold ecosystems in the Qinghai-Tibet Plateau. The interactions between alpine ecosystem and permafrost were investigated with the depth of active layer, permafrost thickness and mean annual ground temperature (MAGTs). Based on the statistics model of GPTR for MAGTs and annual air temperatures, an analysis method was developed to analyze the impacts of permafrost changes on the alpine ecosystems. Under the climate change and human engineering activities, the permafrost change and its impacts on alpine ecosystems in the permafrost region between the Kunlun Mountains and the Tanggula Range of Qinghai-Tibet Plateau are studied in this paper. The results showed that the per- mafrost changes have a different influence on different alpine ecosystems. With the increase in the thickness of active layer, the vegetation cover and biomass of the alpine cold meadow exhibit a significant conic reduction, the soil organic matter content of the alpine cold meadow ecosystem shows an exponential decrease, and the surface soil materials become coarse and gravelly. The alpine cold steppe ecosystem, however, seems to have a relatively weak relation to the permafrost environment. Those relationships resulted in the fact that the distribution area of alpine cold meadow decreased by 7.98% and alpine cold swamp decreased by 28.11% under the permafrost environment degradation during recent 15 years. In the future 50 years the alpine cold meadow ecosystems in different geomorphologic units may have different responses to the changes of the permafrost under different climate warming conditions, among them the alpine cold meadow and swamp ecosystem located in the low mountain and plateau area will have a relatively

关键词： permafrost environment, alpine cold ecosystem, statistics relationship, climate change, impacts, Qinghai-Tibet Plateau.

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Chronology of Holocene lacustrine sediments in Co Ngoin, central Tibetan Plateau

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Science china earth sciences 2006年第9期49卷 991-1001页

作者： WU Yanhong1, WANG Sumin1& HOU Xinhua1,3.1. Key Laboratory of Lake Sedimentation and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of sciences, Nanjing 210008, china 2. Institute of Tibetan Plateau Research, Chinese Academy of sciences, Beijing 10085, china 3. Graduate university of Chinese Academy of sciences, Beijing 10003., china 1. Key Laboratory of Lake Sedimentation and Environment Nanjing Institute of Geography and Limnology Chinese Academy of Sciences Nanjing 210008 China 2. Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing 10085 China 3. Graduate university of Chinese Academy of sciences Beijing 100039 China

Chronology is the basis for using lacustrine sediments to reconstruct the history of en-vironmental change. Radioactive-nuclides such as 14C, 210Pb and 13.Cs dating are mainly used to establish the chronology for recent several ten thousand years. Because of being mixed with “dead carbon”, the measured 14C age is always older than the actual age which is recognized as “reservoir effect”. Cs is a kind of active metal element, and easy to migrate vertically in the sediment that leads to the error of the time marker. 210Pb dating should make sure to select CIC model or CRS model. On the Tibetan Plateau, most of the lakes are alkaline closed lake where Cs is more moveable in the sediment and the reservoir effect caused by “dead carbon” on 14C dating is stronger. Based on the analysis on results of 14C, 210Pb and 13.Cs of the lacustrine sediments from Co Ngoin, central Tibetan Plateau, we use the simple regression method to re-calculate the 14C calendar ages, and establish the time sequence for cores CE-1 and CE-2 with result of 210Pb CRS model for the upper 3. cm and re-calculated 14C calendar age for sediments bellow 3. cm. Since 14.0 cal. a BP, sedimentation inter-rupted for more than 1000 years. According to this time sequence, variations of environmental proxies confidently reflect the major climatic events in Holocene.

关键词： 14C, 210Pb and 13.Cs, chronology, lacustrine sediments, climatic event, Co Ngoin, central Tibetan Plateau.

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Study on lithogeochemistry of Middle Jurassic basalts from southern china represented by the Fankeng basalts from Yongding of Fujian Province

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Science china earth sciences 2006年第10期49卷 1020-1031页

作者： ZHOU Jincheng1,2, JIANG Shaoyong1,2, WANG Xiaolei1,2, YANG Jinghong 1,2 & ZHANG Mengqun 3.1. State Key Laboratory of Mineral Deposit Research, Nanjing university, Nanjing 210093. china 2. Department of earth {3., Nanjing university, Nanjing 210093. china 3. Modern Analysis Center, Nanjing university, Nanjing 210093. china 1. State Key Laboratory of Mineral Deposit Research Nanjing University Nanjing 210093 China 2. Department of earth sciences Nanjing University Nanjing 210093 China 3. Modern Analysis Center Nanjing University Nanjing 210093 China

There exists an E-W trending Middle Jurassic volcanic zone in southern china. The Fankeng basalts in the Yongding basin of Fujian Province are considered to be a typical example. The Fankeng basalts have TiO2 contents in the range of 1.92%-3.21%. They are classified as high-Ti basalts. They also have higher total Fe (averaging FeO* = 11.09%). The Middle Jurassic Fankeng basalts from southwestern Fujian have obvious distinctive lithogeochemical features from early Cre- taceous basalts from southeastern coast of china. They have higher HFSE, such as Th, Nb, Ta, Zr and Ti. Their element ratios related with HFSE, such as Zr/Ba, La/Nb, La/Ta ,Zr/Y, Ti/Y, Ba/Nb, K/Ti and Rb/Zr are similar to those of OIB. The most samples have ε Nd(T) of-0.70-0.24, which are near chondrite. Some samples have higher ε Nd(T) of ***, these basaltic magmas might be derived from depleted asthenospheric mantle. The lithogeochemical characteristics of the Fankeng basalts may be caused by interaction between asthenosphere and lithosphere at the time. The (Early-) Middle Jurassic basalts and gabbros from southeastern Hunan, southern Jiangxi and northern Guangdong provinces show similar geochemical features to those of the Fankeng basalts from the Yongding of Fujian. Occurrence of these OIB-type basalts in the area may be regarded as the petrological mark of upwelling of asthenosphere at the time. Upwelling of asthenosphere has led to tectonic extension and the formation of rifted basin in the area.

关键词： interaction between asthenosphere and lithosphere, lithogeochemistry, basalts, Middle Jurassic, southern china.

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Laser Ablation ICP-MS Titanite U-Th-Pb Dating of the Tonglushan Cu-Fe-Au Skarn Deposit,Southeastern Hubei Province

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矿物学报 2009年第S1期29卷 314-316页

作者： LI Jian-wei 1,2,DENG Xiao-dong1,2,ZHOU Mei-fu3.LIU Yong-sheng1(1. State Key Laboratory of Geological Processes and Mineral Resources,china university of Geosciences,{3. 4.0074,china 2. faculty of earth Resources,china university of Geosciences,{3. 4.0074,china 3. Department of earth sciences,the university of Hong Kong,Hong Kong)

Titanite(CaTi2SiO5) is an important accessory mineral not only in magmatic and metamorphic rocks,but also commonly in hydrothermal mineral deposits. It incorporates appreciable amounts(usually 10×10-6 s to 100×10-6 s) of U and Th into its structure and has a closure temperature of Pb diffusion higher than 660～700 ℃(Scott and St-Onge,1995) ,making it an ideal U-Th-Pb geochronometer. The Daye metallogenic district is located in the west of the giant Middle-Lower Yangtze River(MLYR) Cu-Fe-Au province,eastern china and is well endowed with Fe,Cu,and polymetallic skarn deposits.

关键词： Pb Laser Ablation ICP-MS Titanite U-Th-Pb Dating of the Tonglushan Cu-Fe-Au Skarn Deposit,Southeastern Hubei Province Th Fe ICP Cu MS

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Impact of land-use change on hydrological processes in the Maying River basin, china

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Science china earth sciences 2006年第10期49卷 1098-1110页

作者： WANG Genxu1,3. ZHANG Yu2, LIU Guimin2 & CHEN Lin3.1. Institute of Mountain Hazards and Environment, Chinese Academy of sciences, Chengdu 610041, china 2. Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of sciences, Lanzhou 73.000, china 3. Resource and Environment School, Lanzhou university, Lanzhou 73.000, china 1. Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 China 3. Resource and Environment School Lanzhou University Lanzhou 730000 China 2. Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China

Since the 1960s, dramatic changes have taken place in land-use patterns characterized by the persistent expansion of cultivated land and a continuous decrease in natural woodland and grassland in the arid inland river basins of china. It is very important to assess the effects of such land-use changes on the hydrological processes so vital for water resource management and sustainable development on the catchment scale. The Maying River catchment, a typical arid inland watershed located in the middle of the Hexi Corridor in northwest china, was the site chosen to investigate the hydrological responses to land-use changes. The annual runoff, base flow, maximum peak flow, and typical seasonal runoff in both spring and autumn flood periods were selected as the variables in the hydrological processes. Statistical-trend analysis and curvilinear regression were utilized to detect the trends in hydrological variables while eliminating the climatic influence. The relationship between cultivated land-use and hydrological variables was analyzed based on four periods of land-use variation data collected since 1965. A runoff model was established composed of two factors, i.e., cultivated land use and precipitation. The impact of land use changes, especially in the large ar- eas of upstream woodland and grassland turned into cultivated lands since 1967, has resulted in a mean annual runoff decrease of 28.12%, a base flow decline of 3..3.%, a drop in the maximum peak discharge of 3..77%, and mean discharge decreases in spring and autumn of 3..05% and 24.87% respectively, of which the contribution of cultivated land expansion to the influence of annual runoff amounts to 77%-80%, with the contribution to the influence of spring discharge being 73.-81%, and that to the influence of base flow reaching 62%-65%. Thus, a rational regulation policy of land use patterns is vitally important to the sustainable use of water resources and the proper development of the entire catchment.

关键词： land-use change, arid inland river catchment, hydrological process, impact, Maying River.

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