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Age of Yingfeng rapakivi granite pluton on the north flank of Qaidam and its geological significance

Science china Earth Sciences 2004年第4期47卷 357-365页

作者： XIAO Qinghui1,2. LU Xinxiang1,3, WANG Fei4, SUN Yangui5, WEI Xiangdong3 & XING Zuoyun6 1. Division of Granite Geology, china geological {2., Yichang 443003, china 2. Information Center of Ministry of Land and Resources, Beijing 100812. china 3. geological {2. of henan Province and institute of geological Research of henan Province, zhengzhou 450053, china 4. geological institute, china Seismological Bureau, Beijing 10002., china 5. geological {2. institute of Qinghai Province, Xining 810032. china 6. china University of Geosciences, Wuhan 430074, china Division of Granite Geology China Geological Survey Yichang 443003 China Information Center of Ministry of Land and Resources Beijing 100812 China geological survey of {2. Province and institute of geological Research of {2. Province Zhengzhou 450053 China geological institute China Seismological Bureau Beijing 100029 China geological survey {2. of Qinghai Province Xining 810032 China china University of Geosciences Wuhan 430074 China

The Yingfeng rapakivi granite on the north flank of Qaidam is a newly discovered Proterozoic rapakivi pluton in china, which was found after the discovery of Shachang rapakivi in Miyun County, Beijing and Kuandian rapakivi in Jilin Province. Yingfeng rapakivi pluton is ex-posed on the north side of the suture belt between Qinling-Kunlun orogenic belt and North china plate. U-Pb zircon isotopic dating and Ar-Ar isotopic dating of both hornblende and K-feldspar from the Yingfeng rapakivi granite have been conducted. The results show that the age of (1776±33)Ma at the upper intercept in Concorde diagram represents the age of formation of the plu-ton, whereas the age of (52. 2.1) Ma at the lower intercept and Ar-Ar mineral dating of horn-blende and K-feldspar correspond to the age of a later event affecting the pluton, suggesting that Yingfeng pluton has ever been affected by strong regional Caledonian-Hercynian tectonic movement after its formation. The discovery of middle Proterozoic Yingfeng rapakivi granite pro-vides a petrologic evidence for the timing of cratonization of both the continental crust basement in western china and the basement of the North china plate and for a rifting event taking place in the mid-Proterozoic, suggesting that an amalgamation of ancient china continents had ever happened during the L liang Movement?between the early Proterozoic and the mid-Proterozoic.

关键词： rapakivi, U-Pb dating, Ar-Ar dating, Kunlun-Qinling orogenic belt.

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Carbon isotope composition of the Lower Triassic marine carbonates, Lower Yangtze Region, South china

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Science china Earth Sciences 2006年第3期49卷 225-241页

作者： ZUO Jingxun1,2. TONG Jinnan3, QIU Haiou4 & ZHAO Laishi3 1. Nanjing institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 2.0008, china {2., zhengzhou 4.0007, china 3. State Key Laboratory of geological Processes and Mineral Resources at china University of Geosciences, Wuhan 430074, china 4. Faculty of Material Sciences and Chemical Engineering, china University of Geosciences, Wuhan 430074, china 1. Nanjing institute of Geology and Palaeontology Chinese Academy of Sciences Nanjing 210008 China 2. henan institute of geological survey Zhengzhou 450007 China 3. State Key Laboratory of geological Processes and Mineral Resources at china University of Geosciences Wuhan 430074 China 4. Faculty of Material Sciences and Chemical Engineering China University of Geosciences Wuhan 430074 China

Studies on three Lower Triassic sections located on the shallow water platform, the deep water slope and in the deep water basin in the Lower Yangtze Region, South china, show the similar trend of carbon isotope evolution. Biostratigraphic correlations among the Lower Triassic sections on the basis of standard conodont zones indicate that three negative shifts occurred in the Griesbachian, the Smithian and the late Spathian stages respectively, and one distinctly positive shift occurred in the early Spathian stage. Trend of carbon isotope evolution of the Lower Triassic reflects some significant changes in the global carbon cycle. Moreover, δ 13C background values are intensively controlled by palaeogeographic environment. In general, δ 13C values from deep-water slope carbonates are lighter than those from carbonate platform and heavier than those from deep-water basin carbonates. The positive carbon isotope excursion may be induced by a significant amount of organic carbon burial in marine sediments and increase in primary productivity. The large negative carbon isotope excursions during the Early Triassic in Lower Yangtze Region are interpreted to relate to volcano eruptions based on tuffaceous claystone interlayers observed near the Permian-Triassic boundary, the Induan- Olenekian boundary and the Lower Triassic-Middle Triassic boundary.

关键词： Lower Triassic, carbon isotope compositions, palaeogeography, volcanic eruptions, Lower Yangtze Region.

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Petrogenesis and significance of early Yanshanian syenite-granite complex in eastern Nanling Range

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Science china Earth Sciences 2005年第7期48卷 912-924页

作者： CHEN Peirong1, ZHOU Xinmin1, ZHANG Wenlan1, LI Huimin2. FAN Chunfang1, SUN Tao1, CHEN Weifeng1 & ZHANG Min1 1. State Key Laboratory of Mineral Deposits Research, Department of Earth Sciences, Nanjing University, Nanjing 2.0093, china 2. Tianjin institute of Geology and Mineral Resources, china geological survey, Tianjin 300170, china State Key Laboratory of Mineral Deposits Research Department of Earth Sciences Nanjing University Nanjing 210093 China Tianjin institute of Geology and Mineral Resources China Geological Survey Tianjin 300170 China

In the eastern Nanling Range there exists the early Yanshanian syenite-granite assemblage. A representative example is the Pitou-Tabei complex composed of the Tabei syenite pluton and the Pitou syenogranite pluton in southern Jiangxi Province. U-Pb zircon dating yields ages of 188.6±2.2.Ma for the Tabei pluton and 186.3±1.1 Ma for the Pitou pluton. The Tabei syenite is characterized by relatively low SiO2.content (62.40% - 68.75%), high alkalis (K2.+Na2. = 10.56%-11.96%), low percent K2./Na2. ratios (0.56-0.93), metaluminous fea- ture (A/CNK = 0.80-1.00), enrichment in LILE (Rb, Ba, K) and HFSE (Th, U, Nb, Ta, Zr, and so on), weakly negative to positive Eu anomalies (δ Eu = 0.63-1.82., relatively low (87Sr/86Sr)i (0.70412.0.70543), and relatively high ε Nd(t) (3.14-3.52.. The Pitou syenogranite is charac- terized by high silicon content (SiO2.= 71.06%-76.2.%), relatively low alkalis (K2.+Na2. = 8.10%-9.80%), high percent K2./Na2. ratios (1.2.-1.94), metaluminous feature (A/CNK = 0.94-1.07), enrichment in Rb, Th (U), K, depletion in Ba, Nb, Ta, Sr, P , Zr, Ti, high ΣREE (av- eraging 451.03 μg/g), strong negative Eu anomalies (δ Eu = 0.2.-0.33), relatively high (87Sr/86Sr)i (0.70805-0.70912., and relatively low ε Nd( t ) (?5.35-?6.2.). The Tabei syenite and Pitou syenogranite both have the characteristics of A-type granites. The former is considered to be from the asthenosphere mantle, and the latter was the product of the crust-mantle mixture. They both were probably formed in a rifting setting.

关键词： syenite-granite assemblage single zircon U-Pb age rifting environment Nanling Range.

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^(40)Ar-^(39)Ar dating and geological implication of auriferous altered rocks from the middle-deep section of Q875 gold-quartz vein in Xiaoqinling area, henan,{2.

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Chinese Science Bulletin 2002年第20期47卷 1750-1755页

作者： WANG Yitian, MAO Jingwen, LU Xinxiang & YE Anwanginstitute of Mineral Resources, Chinese Academy of geological Sciences, Beijing 100037,{2. institute of geological Sciences, henan Province, zhengzhou 450053,{2. Lingbao Bureau of Geology and Mineral institute of Mineral Resources Chinese Acad. of Geological Sciences Beijing 100037 China institute of geological Sciences Henan Province Zhengzhou 450053 China Lingbao Bur. of Geol./Mineral Rsrc. Henan Province Lingbao 472500 China

The 40Ar-39Ar age method is employed in this work to analyze the auriferous altered rocks from the middle-deep section of the Q875 gold-quartz vein in the Xiao-qinling area, and the results show that the main gold deposition of the Q875 occurred in ca. 12.-12. Ma. As a typical gold-bearing quartz vein in this gold-rich area, the age data obtained from the Q875 also constrain on the metallogenic time of the lode gold deposits developed in the same geological settings. This geochronological study supplies new evidence for further understanding the timing of gold mineralization, the genesis of gold deposits and the geodynamic settings in Xiaoqinling area.

关键词： 40Ar-39Ar dating auriferous altered rock Q875 gold-quartz vein lode gold deposit metallogenic time Xiaoqinling.

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^(40)Ar/^(39)Ar dating of shear deformation of the Xianshuihe fault zone in west Sichuan and its tectonic significance

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Science china Earth Sciences 2004年第9期47卷 794-803页

作者： ZHANG Yueqiao1, CHEN Wen2. 3 & YANG Nong1 1. institute of Geomechanics, Chinese Academy of geological Sciences, Beijing 100081,{2. 2. institute of Geology, Chinese Academy of geological Sciences, Beijing 100037,{2. 3. institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 10002.,{2. institute of Geomechanics Chinese Academy of Geological Sciences Beijing 100081 China institute of Geology Chinese Academy of Geological Sciences Beijing 100037 China institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China

Based on field geological survey, structural measurements and classical Ar/Ar dating of mica, biotite and K-feldspar, we obtain cooling ages for Miocene left-lateral shear along the Xianshuihe fault zone. The results document two thermal events during the sinistral shear. The early event (12.10 Ma) corresponds to rapid cooling of the Zheduoshan granitic massif from above 700℃ to below 350℃. The late event (5-3.5 Ma) corresponds to cooling of granites intruded along the eastern side of the fault zone. These dating results provide important thermochronological constraint on the timing of late Cenozoic eastward extrusion of the Chuan-Dian Block in the SE Tibetan margin.

关键词： Xianshuihe fault zone, Zheduoshan granitic massif, sinistral shear deformation, 40Ar/39Ar dating, late Cenozoic.

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Tectonic setting of the Helong Block:Implications for the northern boundary of the eastern North china Craton

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Science china Earth Sciences 2005年第10期48卷 1599-1612页

作者： ZHANG Yanbin1, WU Fuyuan1, ZHAI Mingguo1 & LU Xiaoping1,2.1. institute of Geology and Geophysics, Chinese Academy of Sciences, P.O. Box 982., Beijing 10002., china 2. Regional {2. and Mineral Resources survey of Jilin Province, Changchun 130062. china institute of Geology and Geophysics Chinese Academy of Sciences Beijing china Regional geological and Mineral Resources survey of Jilin Province Changchun{2.

LA-ICP-MS zircon U-Pb dating indicates that the Bailiping granitic pluton was em-placed during Late Paleozoic to Early Cretaceous (2.5―116 Ma) by four distinct magmatic epi-sodes, arguing against the previous thought that the Bailiping granites were emplaced during Archean, Proterozoic or Early Paleozoic. It is suggested that the so-called Archean Jincheng-dong granite-greenstone belt, mainly composed of Bailiping granites, should be broken down. Sr-Nd isotopic compositions of the Bailiping granites are similar to those of the Phanerozoic granites in the Xing’an-Mongolian orogenic belt, suggesting that their parental magmas were mainly derived from a juvenile crust with some contamination of ancient crustal materials during magma rising and/or emplacement. Therefore, the basement of the Helong Block is similar to that in the northern Xing’an-Mongolian Orogenic Belt, but different from that of the North china Craton. It is proposed that the Archean Jinchengdong complex in this area is probably an exotic slice from the North china Craton, which indicates that the Fu’erhe-Gudonghe Fault, located in northern part of the Helong area, is not the boundary between the North china Craton and the Xing’an-Mongolian Orogenic Belt. The possible boundary should be located further southward more than 50 km and near the Baitoushan volcano.

关键词： LA-ICPMS ziron U-Pb dating, Bailiping complex, Helong Block, North china Craton, Sr-Nd isotope.

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Glacial atmospheric CO_(2. decline in association with decrease of marine sedimentary phosphorus

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Science china Earth Sciences 2006年第3期49卷 322-330页

作者： WENG Huanxin1, ZHANG Xingmao1, WU Nengyou2. WANG Ying1, CHEN Lihong1, ZHONG Hexian2.& QIN Yachao1 1. institute of Environment & Biogeochemistry, Zhejiang University, Hangzhou 31002., china 2. Guangzhou Marine {2. survey, CGS, MLR, Guangzhou 510760, china 1. institute of Environment & Biogeochemistry Zhejiang University Hangzhou 310027 China 2. Guangzhou Marine geological survey CGS MLR Guangzhou 510760 China

The environmental and biogeochemical information extracted from the sediments col- lected from the northern shelf of the South china Sea shows that terrigenous inputs of phosphorus into the sea remained relatively constant, and the variation of phosphorus contents at different depths was caused by climatic and environmental changes. The findings also suggest that the vertical varia- tion of phosphorus content was opposite to those of calcium carbonate and cadmium, and the func- tional correlation between CO2.and PO43? in seawater was given by calculating the chemical equilib- rium, indicating that the accumulation of marine sedimentary phosphorus may have something to do with the variation of atmospheric CO2. The decreased phosphorus accumulation as well as the cor- respondingly-increased calcium carbonate content might be one of key factors causing glacial at- mospheric CO2.decline.

关键词： sedimentary phosphorus, calcium carbonate, atmospheric CO2. northern shelf of the South china Sea, biogeochemistry.

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3D geological Modeling with Multi-source Data Integration in Polymetallic Region:A Case Study of Luanchuan,henan Province,{2.

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地学前缘 2009年第S1期16卷 166-167页

作者： Gongwen Wang~(1,2.,Shouting Zhang~(1,2.,Changhai Yan~3,Yaowu Song~3,Limei Wang~1 1.School of Earth Sciences and Resources,china University of Geosciences(Beijing),Beijing 100083,china. 2.State Key laboratory of {2. Processes and Mineral Resources,china University of Geosciences,Beijing 100083,china 3.henan institute of {2. survey,zhengzhou 4.0007,china

The development of 3D geological models involves the integration of large amounts of geological data,as well as additional accessible proprietary lithological, structural,geochemical,geophysical,and borehole ***,the c... 详细信息

关键词： 3D geological modeling multi-source data mineral exploration metallogenic model virtual geological section Luanchuan polymetallic region

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A new method for spatio-temporal prediction of rainfall-induced landslide

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Science china Earth Sciences 2006年第4期49卷 421-430页

作者： DING Jixin1,2. YANG Zhifa2. SHANG Yanjun2. ZHOU Shenghua1 & YIN Juntao3 1. china Non-ferrous Metals Resource geological {2., Beijing 100012. china 2. institute of Geology and Geophysics, Chinese Academy of Sciences, Key Laboratory of Engineering Geomechanics, Beijing 10002., china 3. School of Geoscience & Environmental Engineering, Central South University, Changsha 410083, china 1. china Non-ferrous Metals Resource geological {2. Beijing 100012 China 2. institute of Geology and Geophysics Chinese Academy of Sciences Key Laboratory of Engineering Geomechanics Beijing 100029 China 3. School of Geoscience & Environmental Engineering Central South University Changsha 410083 China

geological condition and rainfall are two most principal conditions inducing landslides in the Chongqing region. By analyzing the forming conditions of rainfall-induced landslides, a new method for spatio-temporal prediction of rainfall-induced landslide is brought forward on the basis of grading and overlapping geological condition and rainfall factor in this paper. At first, semi-quantitative assessment and grading for the geological condition of a certain area or slope can be carried out with the multi-factor interactive matrix. Then the severity of rainfall in that area is grading according to the maximum daily rainfall and the total rainfall in a rainfall course. Finally, the “landslide probability judgement factor” can be worked out through grading and overlapping “geological condition influenc- ing factor” and “rainfall influencing factor”, by which the landslide can be graded into 4 grades, they are landslide extremely easily happening, landslide easily happening, landslide difficultly happening and landslide hardly ever happening respectively. More accurate spatio-temporal prediction of rain- fall-induced landslides can come true on the ground of detailed geological survey of some dangerous slopes in an area and more precise weather forecast. Finally, the reliability and feasibility of carrying out the spatio-temporal prediction of rainfall-induced landslides with the method of “two factors” grading and overlapping are validated by the example of Jipazi landslide.

关键词： rainfall-induced landslide, geological condition, rainfall, two factors, grading and overlapping, interactive matrix, spatio-temporal prediction.

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The bio-barite in witherite deposits from Southern Qinling and its significance

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Progress in Natural Science:Materials International 2004年第10期14卷 49-55+98页

作者： Lv Zhicheng 1,2. ,LIU Congqiang 2.,LIU Jiajun 2.and WU Fengchang 2. (1.Development and Research Center,china geological {2.,Beijing100037,china 2.institute of Geochemistry,Chinese Acade-my of Sciences,Guiyang550002.china) china Geol survey Ctr Res & Dev Beijing 100037 Peoples R China Chinese Acad Sci Inst Geochem Guiyang 550002 Peoples R China

Being stratiform or stratoid,the Huangboshuwan witherite deposit at Zhiyang and the Wenyuhe witherite-barite deposit at Zhushan occur in the lower Lower Cambrian siliceous rocks and the orebodies are remarkably controlled by lithological character and *** and oxygen isotopic studies of witherite,barytocalcite and calcite have shown that the carbon,involved in the formation of these minerals,was derived largely from organic carbon resultant from degradation,polycondensation and dehydroxylation of bio-organic matter in sediments at the early stage of *** occurrence of bio-barite strongly evidenced that Ba 2. was concentrated and settled down in the form of bio-barite on the seafloor as a result of biological processes,thereafter forming the initially enriched orebodies of barium *** witherite was metasomatic products of bio-barite under the action of sulfate-reducing bacteria and organic and inor-ganic reduction.

关键词： bio-barite carbon and oxygen isotopes early diagenesis witherite deposits

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