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New data regarding acritarch biostratigraphy from the Early-Middle Cambrian Kaili Formation in Chuandong,Guizhou Province,china

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Progress in Natural Science:Materials International 2009年第1期19卷 107-114页

作者： Leiming Yin a,Ruidong Yang b,Jin Peng c,Fanfan Kong a a nanjing institute of geology and Palaeontology,Chinese Academy of Sciences,nanjing 210008,china b College of Resource and Environment of Guizhou University,Guiyang 550003,china c Department of Sciences of nanjing University,nanjing 210093,china nanjing institute of geology and Palaeontology Chinese Academy of Sciences Nanjing 210008 China College of Resource and Environment of Guizhou University Guiyang 550003 China Department of Sciences of nanjing University Nanjing 210093 China

Previous studies had evaluated acritarchs from the Balang and Pingzhai sections of the Early-Middle Cambrian Kaili Formation in east Guizhou,*** results of these studies suggest that the acritarchs in these sections have potential biostratigraphic *** recently,34 samples collected from 83 m lower part of the Lower-Middle Cambrian Kaili Formation in the Jianshan section of Chuandong,Guizhou Province were prepared for palynological *** of these samples revealed a distinct change in the acritarch assemblages at the bed,which was approximately 46 m above the bottom of the Kaili *** findings suggest a boundary represented by an important alteration of the ecological *** addition,the position of the acritarch biostratigraphic change is somewhat higher than the boundary between Cambrian Series 2 and Series 3 based on trilobites found in the same *** indicates that the distinct change in acritarch assemblages is similar to the change in trilobite assemblages that occurs around the boundary between Cambrian Series 2 and Series ***,acritarch biostratigraphy can provide data that can be used to define the base of Cambrian Series 3 in this region,and possibly worldwide.

关键词： Acritarchs Lower-Middle Cambrian Kaili Formation Jianshan section Chuandong

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Minerogenetic Model for Two Types of Fluorite Deposits in Southeastern china

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Acta Geologica Sinica(English Edition) 1992年第1期66卷 75-88页

作者： Li Changjiang Jiang Xuliang Zhejiang institute of geology and mineral resources, Hangzhou Liu Linqun Zhejiang institute of geology and mineral resources Hangzhou

On the basis of the studies of field geology, strontium, hydrogen and oxygen isotopes and REEgeochemistry, coupled with the dating of mineralization, the authors suggest a minerogenetic model of circula-tion and drawing of Late Cretaceous geothermal waters for the fluorite deposits in southeastern china. Thismodel includes two types of mechanism: 1) the leaching-out and drawing through deep circulation of thegeothermal water, and 2) the leaching-out and drawing through shallow circulation of the water. The fluoritemineralization of Mesozoic volcanic rock terrain is related mainly to the former mechanism, with the mineraliz-ing material coming chiefly from the Precambrian metamorphic rocks of the basement underlying the hostrocks; while that of Yanshanian granite terrain is associated with the latter mechanism, with the mineralizingmaterial derived primarily from the host granites and sedimentary rocks.

关键词： Minerogenetic Model for Two Types of Fluorite Deposits in Southeastern china

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Pollen records of Holocene vegetation and climate changes in the Longzhong Basin of the Chinese Loess Plateau

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Progress in Natural Science:Materials International 2007年第12期17卷 1445-1456页

作者： Tang Lingyu1 and An Chengbang2(1. nanjing institute of geology and Paleontology, Chinese Academy of Sciences, nanjing 210008, china 2. Key Laboratory of Western china’s Environment Systems, MOE, Lanzhou University, Lanzhou 730000, china) nanjing institute of geology and Paleontology Chinese Academy of Sciences Nanjing 210008 China Key Laboratory of Western china's Environment Systems Lanzhou University Lanzhou 730000 China

Pollen records with an average time resolution of 20-200 years from Holocene loess sections at Dingxi, Qin'an, and other localities of Gansu Province reveal a detailed history of vegetation and climate changes in the western Loess Plateau. For most time of the Holocene, the landscape was dominated by grasslands or forest steppes. However, during the middle Holocene (7.5-5.8 ka BP), relatively dense forests developed, and the endemic vegetation flourished, suggesting a much warmer and more humid climate condition than the present. Superimposed upon this general pattern are several dry intervals marked by the episodic expansion of grasslands or forest steppe. Xeric vegetation expanded after 3.8 ka BP, indicating a trend towards dry conditions.

关键词： pollen records glasslands coniferous forests Holocene Loess Plateau.

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One-step estimation for varying coefficient models

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Science china Mathematics 2005年第2期48卷 198-213页

作者： TANG Qingguo & WANG Jinde Department of Mathematics, nanjing University, nanjing 210093, china institute of Sciences, PLA University of Science and Technology, nanjing 210007, china Department of Mathematics Nanjing University Nanjing China institute of Sciences PLA University of Science and Technology Nanjing China

A one-step method is proposed to estimate the unknown functions in the varying coefficient models, in which the unknown functions admit different degrees of smoothness. In this method polynomials of different orders are used to approximate unknown functions with different degrees of smoothness. As only one minimization operation is employed, the required computation burden is much less than that required by the existing two-step estimation method. It is shown that the one-step estimators also achieve the optimal convergence rate. Moreover this property is obtained under conditions milder than that imposed in the two-step estimation method. More importantly, as only one minimization operation is employed, the full asymptotic properties, not only the asymptotic bias and variance, but also the asymptotic distributions of the estimators can be derived. The asymptotic distribution results will play a key role for making statistical inference.

关键词： varying coefficient model, one-step estimation, asymptotic distribution, optimal convergence rate.

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Lead Isotope Studies of Massive Surphur-Iron-Gold Deposits in the Tongling Area, Anhui Province

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Acta Geologica Sinica(English Edition) 1992年第2期66卷 177-189页

作者： Huang Bin Research institute of geology and mineral resources, china National Nonferrous Metals Industry Corporation. Guilin, Guangxi Sun Sheping Research institute of geology and mineral resources China National Non ferrous Metals Industry Corporation Guilin Guangxi

Pb isotope ratios and their variation have been measured and explained on ores of massive S-Fe-Au depos-its hosted in the Middle-Upper Carboniferous, on feldspars from diorite bodies closely related tomineralization and on whole rocks from ore-hosting strata (carbonate rocks) in the Tongling area, Anhui Prov-ince. Through a comparison of Pb isotope features of these geological bodies, it has been suggested that oresubstances of the deposits were derived from ore-hosting strata. In the meanwhile, the measurement of ore Pbisotopes of different mineralization types of the same deposit indicates that different mineralization types havedistinct Pb isotope characteristics, showing the potentiality of the Pb isotopic method used in mineral explora-tion.

关键词： Pb Anhui Province Lead Isotope Studies of Massive Surphur-Iron-Gold Deposits in the Tongling Area Gold

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Early-Mid Ordovician brachiopod diversification in South china

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Science china Earth Sciences 2005年第5期48卷 662-675页

作者： ZHAN Renbin, RONG Jiayu, CHENG Jinhui & CHEN Pengfei nanjing institute of geology and Palaeontology, Chinese Academy of Sciences State Key Laboratory of Palaeobiology and Stratigraphy, nanjing 210008, china nanjing institute of geology and Palaeontology Chinese Academy of Sciences State Key Laboratory of Palaeobiology and Stratigraphy Nanjing China

Affected by paleogeographic position, paleoclimatic condition and depositional environments, the increase of the Early-Mid Ordovician brachiopod diversity of South china commenced at the beginning of the Ordovician (early Tremadoc), accelerated from the Tetra- graptus approximatus Biozone (base of Arenig), and reached its first acme in the Didymograptus eobifidus Biozone (mid early Arenig) when the number of brachiopod genera was over 7 times as great as that at the start of the Ordovician. This was the first radiation in the history of brachiopod macroevolution in South china, which occurred nearly 5 graptolitic biozones earlier than the global trend of the great Ordovician biodiversification (in the lower part of the Undulograptus austrodentatus Biozone). It is also characterized by (1) the origination or first occurrences of some major groups, such as the punctate dalmanelloids and the pseudopunctate stro- phomenoids including Plectambonitoidea (cardinal process simple or absent) and Stro- phomenoidea (cardinal process bilobed) in South china; (2) niche expansion, particularly in the first occupation of deeper water benthic regimes by the Euorthisina-Nocturnellia Association developed at Houping, Chengkou, northern Chongqing; and (3) the differentiation of brachiopod faunas under different environmental conditions. The gradual and increasing separation from Gondwana may have been one of the factors responsible for the radiation in South china.

关键词： biodiversity, evolutionary radiation, brachiopods, Early-Mid Ordovician, South china.

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Types, Metallogenic Environments and Characteristics of Temporal and Spatial Distribution of Copper Deposits in china

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Acta Geologica Sinica(English Edition) 1989年第1期63卷 79-92页

作者： Wang Zhitian and Qin Kezhang Beijing institute of geology for mineral resources, CNNC, Beijing Zhang Zhongmin Beijing institute of geology for mineral resources CNNC Beijing

Based upon a comprehensive study of 123 copper deposits in china. this paper reaches the following conclusions: 1. The crust in china was solidified pretty late; with the accretion of the plate, the copper mineralization moved towards its margin in space and became successively younger in age. 2. The major copper ore types ever found in the world have mostly been discovered in china, in which the porphyry type seems to be the most important and the massive sulfide type in the transitional bed between marine clastic and carbonate rocks is clearly defined. 3. Carbonate strata are widespread in china and their deposition lasted for a long geological period, so the proportion of copper deposits occurring in them is large as compared with other parts of the world. 4. Seven metallogenic epochs can be recognized, in which the Mesozoic one plays the leading role and the middle(late) Palaeozoic and Cenozoic ones are next in importance. mineralization was comparatively simple in the early geological period. and became diversified later on. In the early epochs copper deposits related to basaltic magmatism and metamorphosed marine sediments predominated, whereas in the later epochs those related to granitic magmatism and continental sedimentation were dominant. 5. There exist in china thirteen metallogenic provinces, of which the Lower Yangtze downwarping belt, Sanjiang fold system, Jiangnan axis and Xikang-Yunnan axis are of greater significance. 6. The crustal mobility in china was rather pronounced, the polycyclic evolution of the crust has resulted in such obvious phenomena as the inheritance of mineralization, the coexistence of various types and the superposition of different genetic types.

关键词： Metallogenic Environments and Characteristics of Temporal and Spatial Distribution of Copper Deposits in china Types

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Sorption behavior of U(VI), ^(234)U(VI) and ^(238)U(VI) onto fracture-filling clays in Beishan granite, Gansu: Application to selecting the site of high-level radwaste repository in china

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Science china Earth Sciences 2005年第10期48卷 1649-1655页

作者： MIN Maozhong1,2, LUO Xingzhang3, WANG Ju4, JIN Yuanxin4 & WANG Rucheng1 1. Department of Earth Sciences, State Key Laboratory of mineral Deposit Research, nanjing University, nanjing 210093, china 2. Center of Materials Analysis, nanjing University, nanjing 210093, china 3. Department of Environmental Science and Engineering, nanjing University, nanjing 210093, china 4. Beijing geology institute, Nuclear Industry, Beijing 100029, china nanjing University Nuclear Industry

The first results of sorption experiments of U(VI), 234U(VI) and 238U(VI) onto original (unpurified) fracture-filling clays from No.1 monzonitic granite intrusion, Beishan area, Gansu Province, china are reported. The monzonitic granite intrusion is a potential location for a high-level radwaste (HLW) repository in china. The present experimental results show that the maximum U(VI) sorption reached 92% at near-neutral pH and the distribution coefficient (Kd) was 1226 mL/g. A high sorption capacity of the fracture-filling clays in host rock on radioactive ele-ments is necessary for HLW deep geological disposal repository. No preferential sorption of 234U onto the clays was found. Finally, the sorption of U(VI) onto the clays was also modeled using a surface complexation model.

关键词： HLW geological disposal repository, granite, uranium, radionuclide, clay, sorption.

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Activation of fly ashes by the high temperature and high alkalinity in ASR tests

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Science china(Technological Sciences) 2011年第S1期54卷 28-32页

作者： CAI YueBo ,DING JianTong & BAI Yin State Key Laboratory of Hydrology-Water resources and Hydraulic Engineering,nanjing Hydraulic Research institute,nanjing 210029,china State Key Laboratory of Hydrology-Water resources and Hydraulic Engineering Nanjing Hydraulic Research Institute Nanjing China

High temperature and high alkalinity are typical testing conditions to accelerate the appraisal process of the suppressing effect of fly ashes on alkali silica reaction(ASR),but the reaction mechanism of fly ashes would be quite different under such conditions compared to the normal condition of temperature and *** make a reasonable analysis of the suppressing effect of fly ashes,13 types of fly ashes were tested in this paper by both the accelerated mortar bar test method and the 60°C accelerated concrete prism test *** results showed that the effect of fly ashes would be magnified under the condition of high temperature and high *** XRD analysis showed that all the phases of fly ash could react with the hot alkaline solution except for mullite and a small amount of *** ash could be significantly activated by the 80°C 1 mol/L NaOH solution,and form mainly C-S-H phase and P type zeolite,but its effect on inhibiting ASR was exaggerated *** to the mortar strength test and the ASR suppressing test results,C-S-H phase contributed to mortar strength,but its amount did not decide the ASR suppressing effect of fly ash.

关键词： fly ash Alkali silica reaction Activation

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Ore-forming fluid and mineralization of Caijiaying and Dajing polymetallic ore deposits

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Science china Earth Sciences 2004年第2期47卷 97-107页

作者： WANG Lijuan,WANG Jingbin, WANG Yuwang & ZHU Heping1. Key Laboratory of mineral resources, institute of geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, china 2. Beijing institute of geology for mineral resources, Beijing 100012, china Correspondence should be addressed to Wang Lijuan (email: wlj@***) Key Laboratory of mineral resources Institute of Geology and Geophysics Chinese Academy of Sciences Beijing China Beijing institute of geology for mineral resources Beijing China

Fluid inclusions from the Dajing and Caijiaying deposits have nearly the same homogenization temperature. Correlation between temperature and salinity shows that both Sn- and Cu-bearing fluids Sn and Cu were present in the Dajing deposit but only one kind of fluids continuously evolved in the Caijiaying deposit. Study on rare earth elements (REE) in ancient fluid from the inclusions indicates that the fluid of Sn mineralizing stage in Dajing was derived from remelting magma of the continental crust, and the fluid of Cu-Pb-Zn mineralizing stage in the Dajing deposit and the fluid of Cu-Pb-Zn mineralization in the Caijiaying deposit were derived from the mantle. It is concluded that the Cu-Pb-Zn mineralizations in the Dajing and Caijiaying deposits resulted from the identical tectono-thermal event of magma-fluids induced by Mesozoic tectonic transition and extension in the eastern part of North china Craton.

关键词： Caijiaying, Dajing, Mesozoic tectonic transition, ore-forming fluid, REE.

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