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mineralization episode of porphyry copper deposits in the Jinshajiang-Red River mineralization belt: Re-Os dating

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Science china Earth sciences 2005年第2期48卷 192-198页

作者： WANG Denghong, QU Wenjun, LI Zhiwei, YIN Hanlong4 & CHEN Yuchuan institute of mineral resources,{3., beijing 100037, china National Center of Rock and mineral Analysis,{3., beijing 100037, china resource Assessment Center of Yunnan, Kunming 650011, china institute of Geology and Geophysics, {13. academy of sciences, beijing 100101, china {13. academy of geological sciences, beijing 100037, china institute of mineral resources Chinese Academy of Geological Sciences Beijing China National Center of Rock and mineral Analysis Chinese Academy of Geological Sciences Beijing China resource Assessment Center of Yunnan Kunming China institute of Geology and Geophysics Chinese Academy of Sciences Beijing China chinese academy of geological {3. Beijing China

Re-Os isotopic dating for the molybdenites from the porphyry copper deposits of the Jinshajiang-Red River mineralization belt in Yunnan Province yields isochron ages of 3..9±1.1 Ma for the Machangqing deposit and 3..4±0.5 Ma for the Tongchang deposit. This result shows that both the Machangqing and the Tongchang porphyry Cu-Mo deposits from two different ore-fields formed simultaneously. This new data and the published Re-Os model ages of molybdenite (3..4 Ma, 3..9 Ma, 3..2 Ma) of the Yulong porphyry copper deposit in Tibet, which is located in the same Jinshajiang-Red River mineralization belt as the Machangqing deposit and the Tongchang deposit, suggest that these three Cenozoic porphyry copper deposits in the Jinshajiang-Red River mineralization belt were contemporary for their mineralization episode. That is to say, even their present locality is far away and nearly iso-distantly distributed, these three porphyry Cu(Mo) deposits belong to the same mineralization episode at the end of Eocene.

关键词： Re-Os isotopic dating, porphyry Cu deposits, Cenozoic, mineralization episode.

^(40)Ar/^(3.)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,{3. 2. institute of Geology, chinese academy of geological sciences, beijing 100037,{3. 3. institute of Geology and Geophysics, chinese academy of sciences, beijing 100029,{3. institute of Geomechanics Chinese Academy of Geological Sciences Beijing China institute of Geology Chinese Academy of Geological Sciences Beijing China institute of Geology and Geophysics Chinese Academy of Sciences Beijing 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 3.0℃. 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/3.Ar dating, late Cenozoic.

The effects of K^+ growth conditions on the accumulation of cesium by the bacterium Thermus sp. TibetanG6

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Science china(Life sciences) 2006年第2期49卷 123-129页

作者： WANG Hailei1,2,3. KONG Fanjing1,2,3.& ZHENG Mianping1,2,3.1. R&D Center for Saline Lake and Epithermal Deposits, chinese academy of geological sciences, beijing 100037, china 2. Key Open Laboratory of Saline Lake {3.s and Environment, chinese academy of geological sciences, beijing 100037, china 3. institute of mineral resources, chinese academy of geological sciences, beijing 100037, china R&D Center for Saline Lake and Epithermal Deposits Chinese Academy of Geological Sciences Beijing China Key Open Laboratory of Saline Lake resources and Environment Chinese Academy of Geological Sciences Beijing China institute of mineral resources Chinese Academy of Geological Sciences Beijing China

The accumulation of cesium by the bacterium Thermus sp. TibetanG6 was examined under different K+ growth conditions. The effects of external pH and Na+ on the accumulation of ce-sium were also studied, and the mechanism involved was discussed. K+ regimes played an important role in the accumulation of cesium by the strain TibetanG6. The quantity of cesium accumulated (24 h) was much higher in K+-deficient regime than that in K+-sufficient regime. The pH and Na+ had different effects on the accumulation of cesium in the two K+ regimes. IR spectra analyses indicated that the biosorption is a process of homeostasis with cesium initially accumulated on the cell wall.

关键词： Thermus sp. TibetanG6, cesium, bioaccumulation, K+-growth condition, pH, sodium, IR spectroscopy.

Crustal structure of Gondwana-and Yangtze-typed blocks:An example by wide-angle seismic profile from Menglian to Malong in western Yunnan

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Science china Earth sciences 2005年第11期48卷 1828-1836页

作者： ZHANG Zhongjie1, BAI Zhiming1, WANG Chunyong2, TENG Jiwen1, Lü Qingtian3. LI Jiliang1, SUN Shanxue1 & WANG Xinzheng1 1. institute of Geology and Geophysics, chinese academy of {3., beijing 100029, china 2. institute of Geophysics, chinese Seismological Bureau, beijing 100081, china 3. institute of Deposition resource, chinese academy of geological sciences,{13., china institute of Geology and Geophysics Chinese Academy of Sciences Beijing China institute of Geophysics Chinese Seismological Bureau Beijing China institute of Deposition resource Chinese Academy of Geological Sciences Beijing China

The wide-angle seismic profile between Menglian and Malong crosses the Baoshan block (Gondwana-typed), and Simao and southwestern Yangtze blocks (Yangtze-typed). By in-terpreting the wide-angle seismic data, we obtained the seismic crust/upper mantle structure of P-wave velocities together with the seismic reflections of these three blocks, Changning- Menglian and Mojiang suture zones among the mentioned three blocks. Our interpreting results demonstrate that the P-wave crustal velocity of Simao block is slower than that of Baoshan and southwestern Yangtze block and the crustal thickness gradually thickens from the Baoshan block, Simao to southwestern Yangtze block. Crustal reflection patterns of these three blocks have dis-tinct differences too. For the Gondwana-typed blocks, seismic reflections in the upper crust are well developed while in middle-lower crust they are very weak. The crustal reflections in the Yangtze block are very well developed. The crustal reflection patterns in Simao and southwest-ern Yangtze blocks are distinguishable. The average thickness of the crust in the studied area is about 40 km. And we make some discussions on the crustal thickening model of the three blocks in western Yunnan and tectonic setting of seismic developing and interaction of Gondwana and Yangtze blocks.

关键词： Gondwana blocks,Yangtze blocks,wide-angle profile,crustal structure,tectonic setting

The possible contribution of a mantle-derived fluid to the Ningwu porphyry iron deposits—Evidence from carbon and strontium isotopes of apatites

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Progress in Natural Science:Materials International 2008年第2期18卷 167-172页

作者： Jinjie Yu ,Jingwen Mao,Changqing Zhang institute of mineral resources,{3. academy of geological Science,beijing 100037,china institute of mineral resources Chinese Academy of Geological Science Beijing 100037 China

Apatite is a characteristic mineral for the iron deposits in the Ningwu region. Apatite shows a range of d13.PDB values from à9.6& to à0.6&,and most of them with the d13.PDB values distributed in a range of mantle carbon (i.e.,à2& to à9&),except for samples T-06-1 and J-06-3. Apatites in the Ningwu porphyry iron deposits yield a narrow variation range of 87Sr/86Sr values from 0.7063.6 to 0.707577,similar to those of the volcanic and subvolcanic rocks and higher than that of a typical mantle-derived magmatic apatite (i.e.,about 0.7040),indicating that formation of the apatites was involved with crust material contamination. d13.PDB and 87Sr/86Sr values of the apatite indicate a possible contribution of mantle-derived fluid and material to formation of the Ningwu porphyry iron deposits,supported by regional geology,regional gravities and geochemistry of the volcanic and subvolcanic rocks in the Ningwu region.

关键词： Apatite 87Sr/86Sr ratios Fluid inclusion d13. Mantle fluid and material

Underplating in the middle-lower Yangtze Valley and model of geodynamic evolution:Constraints from geophysical data

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Science china Earth sciences 2005年第7期48卷 985-999页

作者： Lü Qingtian, HOU Zengqian, YANG Zhusen & SHI Danian institute of mineral resources,{3. academy of geological sciences,beijing 100037,china institute of mineral resources Chinese Academy of Geoloqical Sciences Beijina 100037 China

The lower crust and Moho are the most active boundary layers in the process of continental evolution, in which marks left by tectonic and magmatic activities during the process are preserved. The evolutionary process of the continental lithosphere may be reconstructed by exploring the structures of the lower crust and Moho. According to a study of the deep seismic reflection data obtained from the middle-lower Yangtze Valley, the authors find bright layered reflections ubiquitous in the lower crust and think that the bright reflections are caused by un-derplating of basic or ultrabasic magmas, which might be related to delamination of the lithosphere. On the basis of an integrated analysis of the geophysical and geological data of the region, the authors propose a model for geodynamic evolution of the middle-lower Yangtze Valley. This model suggests that the middle-lower Yangtze Valley had undergone such geodynamic processes as collision-compression, delamination-extension and underplating-melting since the end of the Permian, finally forming the gigantic middle-lower Yangtze Valley metallogenic belt.

关键词： lower crust deep seismic reflection underplating tectonic evolution.

The Coexisting Clinopyroxene-Garnet Acidometer and Acidity Facies of Skarn Deposits

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Acta Geologica Sinica(English Edition) 1990年第3期64卷 299-308页

作者： Lin Wenwei institute of mineral Deposits, chinese academy of geological sciences, {3. Liu Linqun institute of mineral Deposits Chinese Academy of Geological Sciences Beijing

On the basis of geological studies of skarn deposits in china and by using thermodynamic models of thesolid solution, the coexisting clinopyroxene-garnet pair in skarn deposits has been analysed and a coexistingclinopyroxene-garnet acidometer developed. They can be used to estimate the medium condition under whichthe skarn was formed. The research on the acidity for the formation of various metallic skarn deposits in chinasuggests that skarns endowed with dissimilar types of {3.ization and occurring in diverse environments dif-fer in the acidity conditions for their formation and in the trend of acidity variation of ore-bearing fluid. This,coupled with the study of oxygen fugacity of coexisting {3.s, makes it possible to establish the oxygenfugacity-acidity facies of skarn deposits, which reflect the close genetic relationship between the metallizationand the formation of skarn.

关键词： OH The Coexisting Clinopyroxene-Garnet Acidometer and Acidity Facies of Skarn Deposits

SHRIMP zircon U-Pb geochronology of early Mesozoic felsic igneous rocks from the southern Lancangjiang and its tectonic implications

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Science china Earth sciences 2006年第10期49卷 1032-1042页

作者： PENG Touping1,2, WANG Yuejun1, FAN Weiming1, LIU Dunyi3. SHI Yuruo3.& MIAO Laicheng4 1. Key Laboratory of Isotope Geochronology and Geochemistry, Guangzhou institute of Geochemistry, chinese academy of {3., Guangzhou 510640, china 2. Graduate University of chinese academy of {3., beijing 10003., china 3. SHRIMP isotope Laboratory, chinese academy of geological sciences, beijing 100037, china 4. institute of Geology and Geophysics, chinese academy of {3., beijing 100029, china Key Laboratory of Isotope Geochronology and Geochemistry Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou China Graduate University of chinese academy of sciences Beijing China SHRIMP isotope Laboratory Chinese Academy of Geological Sciences Beijing China institute of Geology and Geophysics Chinese Academy of Sciences Beijing China

The SHRIMP zircon U-Pb geochronology of three typical samples, including two monzo nitic granites from the Lincang batholith and a rhyolite from the Manghuai Formation are presented in the southern Lancangjiang, western Yunnan Province. The analyses of zircons for the biotite monzonitic granites from the northern (02DX-13.) and southern (20JH-10) Lincang batholith show the single and tight clusters on the concordia, and yield the weighted mean 206Pb/23.U ages of 229.4 ± 3.0 Ma and 23..4 ± 3.6 Ma, respectively, representing the crystallized ages of these granites. The zircons for the rhyolitic sample (02DX-95) from the Manghuai Formation give a weighted mean 206Pb/23.U age of 23..0 ± 5.0 Ma. These data suggest that the igneous rocks from the Lincang granitic batholith and Manghuai Formation have a similar crystallized age. In combination with other data, it is inferred that both were generated at a narrow age span (~23. Ma) and were originated from the postcollisional tectonic regime. An early Proterozoic 206Pb/23.U apparent age of 1977±44 Ma is additionally obtained from one zircon from the biotite monzonitic granite (southern Lincang batholith), indicative of devel- opment of the early Proterozoic Yangtze basement in the region. These precisely geochronological data provide important constraints on better understanding the Paleozoic tectonic evolution of the Tethys, western Yunnan Province.

关键词： SHRIMP zircon U-Pb dating, Middle Triassic, Lincang granitic batholith, Manghuai Formation rhyolite, southern Lancangjiang.

^(40)Ar-^(3.)Ar dating and geological implication of auriferous altered rocks from the middle-deep section of Q875 gold-quartz vein in Xiaoqinling area, Henan,china

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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,{3., beijing 100037, china institute of geological sciences, Henan Province, Zhengzhou 450053. china 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-3.Ar 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. 128-126 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-3.Ar dating auriferous altered rock Q875 gold-quartz vein lode gold deposit metallogenic time Xiaoqinling.