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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,{2., beijing 100081, China 2. institute of Geology,{2., beijing 100037, China 3. institute of Geology and Geophysics, chinese academy of sciences, beijing 10002., China 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 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.

Discovery of low grade metamorphic volcanic rock sheets within UHP in Dabie Mts. and its implications

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chinese Science Bulletin 1997年第14期42卷 1199-1203页

作者： DONG Shuwen, WANG Xiaofeng and HUANG Dezhi1. chinese academy of geological sciences (CAGS), beijing 100037, China {2. of CAGS, beijing 100081 China 3. Anhui institute of geological sciences, Hefei 2.0001 chinese academy of {2. sciences (CAGS) Beijing 100037 China

THE ultrahigh-pressure metamorphic zone (UHP), outcropping in the central and southernDabie Mts. with an area of about 1000 km^2. may be the largest one in the world. The forma-tion and exhumation mechanism of the UHP rocks become a hot point in the study of continen-tal orogen. The first finding of the Shiqiao structural window, which is composed of low

关键词： ultrahigh-pressure metamorphic zone (UHP) low grade metamorphic rock sheets Dabie Mts.

SHRIMP zircon U-Pb age and Nd isotopic study on the Nyainqêntanglha Group in Tibet

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Science China Earth sciences 2005年第9期48卷 1377-1386页

作者： HU Daogong1, WU Zhenhan1, JIANG Wan1, SHI Yuruo2. YE Peisheng1 & LIU Qisheng1 1. institute of geomechanics,{2., beijing 100081, China 2. institute of Geology,{2., beijing SHRIMP Centre, beijing 100037, China institute of geomechanics Chinese Academy of Geological Sciences Beijing China institute of Geology Chinese Academy of Geological Sciences Beijing SHRIMP Centre Beijing China

The Nyainqêntanglha Group is traditionally viewed as the oldest metamorphic basement in the Lhasa block, but its formation age and tectonic setting remain debate. Zircons extracted from the metamorphic sequence of volcanics and intrusions of the Nyainqêntanglha Group, 10 km west of Nam Co in northern Lhasa block, have been investigated by cathodolu- minescence (CL), backscattered (BSE) and dated by ion microprobe (SHRIMP). We conclude that the U-Pb age of 787±9 Ma of zircons from the trondhjemite imposes a constraint on maxi- mum protolith age, and minimum formation age of the Nyainqêntanglha Group is constrained by U-Pb age of 748±8 Ma of zircons from the granite. The formation age of the Nyainqêntanglha Group is consistent with sedimentary age of Greater Himalayan rocks, showing that they devel- oped coevally in an arc-basin tectonic setting of Neoproterozoic active continental margin along the northern margin of the India shield. The inherited zircons from the tholetiite and granite give older 2.7Pb/2.6Pb ages from 947 to 1766 Ma. The positive εNd( t ) value indicates that the mafic rocks were derived from the depleted mantle, but contaminated by the older continental crustal material. Integrated Nd model age and U-Pb age data provide excellent evidence for the exis- tence of Mesoproterozoic basement in the Lhasa block during Neoproterozoic time.

关键词： Nyainqêntanglha Group, SHRIMP dating, Nd isotope, Neoproterozoic, Tibet.

The Mechanism of Structural Control of Ore Formation and Geochemical Characteristics in the Massive Sulfide Deposits of the Wushan Copper Ore Field,Jiangxi

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Acta Geologica Sinica(English Edition) 1990年第3期64卷 261-274页

作者： Liu Xun institute of geomechanics,{2., beijing Zhang Zhongmin institute of geomechanics Chinese Academy of Geological Sciences Beijing

The ore-controlling mechanism of the bedding fault system in the massive sulfide deposits of the Wushancopper orefield may be generalized as the control of ore deposition by optimum surface in an ore-formingstructural trap. The mechanism has three major features: (1) timing of mineralization; (2. positioning of hostformation; and (3) dependence of ore-controlling structure on properties of rocks. The 'optimum surface' is adivisional structural plane which marks obvious difference in physical, chemical and mechanical properties andis favorable for mineralization. It is also a unity of structures. lithofacies and orebodies. The structural and geochemical characteristics of the ore deposits indicate the migration trend of the ma-jor characteristic clements in the ore-controlling fault belt: elements with a small radius (Si, Fe, Mg and Al)moved towards and concentrated at the center of the belt while large-radius ones (Ca, K and Na) were remotefrom the center.

关键词： The Mechanism of Structural Control of Ore Formation and Geochemical Characteristics in the Massive Sulfide Deposits of the Wushan Copper Ore Field Jiangxi

Grain-size features of a Miocene loess-soil sequence at Qinan: Implications on its origin

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Science China Earth sciences 2006年第7期49卷 731-738页

作者： QIAO Yansong1,3, GUO Zhengtang2.1, HAO Qingzhen1, YIN Qiuzhen1, YUAN Baoyin1 & LIU Tungsheng1 1. institute of Geology and Geophysics, chinese {2. of sciences, beijing 10002., China 2. institute of Earth Environment, chinese {2. of sciences, Xi’an 710075, China 3. institute of geomechanics, chinese academy of geological sciences,{12., China institute of Geology and Geophysics Chinese Academy of Sciences Beijing China institute of geomechanics Chinese Academy of Geological Sciences Beijing China institute of Earth Environment Chinese Academy of Sciences Xi’an China

In this study, grain-size of 507 bulk samples from the QA-I Mioceneloess-soil sequence at Qinan were analyzed, and the grain-size features are compared with those oftypical Quaternary loess and soil samples, representative lacustrine and fluvial samples. Theresults indicate that the grain-size distribution pattern of the Miocene loess is essentiallysimilar to that of Quaternary loess, but greatly differs from the lacustrine and fluvial *** layers are regularly coarser than soil layers, indicating cyclical climate changes. Mediangrain-size along the 2.3.1 m sequence varies from 6 to 13 μm and the > 63 μm fraction representsonly 5.3% in maximum, 0.9% in average. Long-term grain-size variations are consistent with the loessaccumulation rate at Qinan and with the eolian mass accumulation rate in the North Pacific. Thesefeatures firmly indicate an eolian origin of the studied sequence, and also reveal a coeval changesbetween the long-term changes of eolian grain-size and continental aridity in the dust sourceregions.

关键词： Qinan, Miocene loess-soil sequence, grain-size, eolian origin.

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 {2. of sciences, beijing 10002., China 2. institute of Geophysics, chinese Seismological Bureau, beijing 100081, China 3. institute of Deposition Resource, chinese academy of geological sciences, beijing 100037, 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

U-Pb dating of zircon from the bed parallel anatectic granitic intrusion in the Baoban group in Hainan Island and the tectonic implication

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Science China Earth sciences 2005年第12期48卷 2092-2103页

作者： DING Shijiang1, HU Jianmin2. SONG Biao3,4, CHEN Mulun1, XIE Shengzhou1 & FAN Yuan1 1. geological Surveying institute of Hainan, Haikou 5702.6, China {2., chinese academy of geological sciences, beijing 100081, China 3. beijing Center of SHRIMP, beijing 100037, China 4. institute of Geology, chinese academy of geological sciences, beijing 100037, China geological Surveying institute of Hainan Haikou China institute of geomechanics Chinese Academy of Geological Sciences Beijing China beijing Center of SHRIMP Beijing China institute of Geology Chinese Academy of Geological Sciences Beijing China

The petrological and geochemical features of the bed parallel granitic intrusion in the Pre-Cambrian Baoban group in Hainan Island attest to the anatexis origin of the granites. U-Pb dating analyses of zircons from the anatectic granite and the biotite two-feldspar gneiss in the Baoban group, using SHRIMP II in the beijing Ion-probe Center, acquire 2.6Pb/2.8U ages of 368±3.5 Ma (of granite, 95% confidence level, MSDW=1.2.) and 362.9±6.1 Ma (of gneiss, 95% confidence level, MSDW = 2.04) respectively. The two late Devonian ages indicate consistently a tectonic- thermal event experienced in Hainan Island, and are the first discovered record of the Devonian geological process in the district. This event possibly resulted from the deep ther-mal-dynamic process when the Gondwana continent began to break up in the Devonian period.

关键词： Hainan Island, Devonian period, anatectic granite, zircon SHRIMP U-Pb dating.

The upper mantle structure of the Tibetan Plateau and its implication for the continent-continent collision

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Science China Earth sciences 2005年第8期48卷 1158-1164页

作者： WU Qingju1, ZENG Rongsheng1 & ZHAO Wenjin2.1. institute of Geophysics, China Earthquake Administration, beijing 100081, China 2. institute of Geology, China academy of geological sciences, beijing 100037, China institute of Geophysics China Earthquake Administration Beijing China institute of Geology China Academy of Geological Sciences Beijing China

The upper mantle structures of Himalayas-Tibet have been obtained from the mi-gration of receiver functions of the teleseismic events recorded by INDEPTH-III. The result of migration imaging shows a dipping interface subducting northward from the depth of 100 km to the 410-km discontinuity underneath southern Tibet. It indicates that the lithospheric mantle of the Indian continent had been detached from the crust and deeply subducted to the upper mantle of Eurasia during the Indo-Eurasian collision. This kind of continent-continent collision process is fundamentally different from the oceanic collision.

关键词： Tibetan Plateau, receiver function, upper mantle structures, Indo-Eurasian collision, dipping interface.

Persistent anomalous flows over the subtropical western Pacific insummer

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chinese Science Bulletin 1998年第8期43卷 672-675页

作者： ZHUANG Shiyu\+1 and JI Liren\+2.1. National Meteorological Centre, China Meteorological Administration, beijing 100081, China 2. LASG, institute of Atmospheric Physics, {2. academy of sciences, beijing 100080, China National Meteorological Ccntre China Meteomlcgical Administration Beijing China LASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China

The distribution of global persistent anomalies shows that the subtropical western Pacific is a key region with high_frequency occurrence of persistent anomalies. Analyses of streamfunction anomalies, OLR anomalies etc. suggest that the convective heating related to Indian monsoon might be responsible for the development of WPA. The results of numerical experiment by two linear barotropic models support the observation.

关键词： persistent anomalies subtropical high Indian monsoon anomalous forcing.

Principles and methods of quantitative analysis on b-axis disorder in 2.: 1 dioctahedral phyllosilicate

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chinese Science Bulletin 1997年第22期42卷 1908-1912页

作者： WANG Ling and ZHANG Zhenyu1. Changsha institute of Geotectonics, chinese {2. of sciences, Changsha 410013, China 2. institute of Geology, chinese {2. of sciences, beijing 10002., China Changsha institute of Geotectonics Chinese Academy of Sciences Changsha China institute of Geology Chinese Academy of Sciences Beijing China

IN XRD patterns of clay minerals, a phenomenon that strong peaks often have (00l) and(hkl) (k=3n) indices and show symmetric figures can be seen commonly, while a minorityof reflection peaks (hkl) (k≠3n) are comparat... 详细信息

关键词： b-axis disorder pyrophvllile 2 phyllosilicate clay minerals dioctahedral minerals orientating structure of hy-droxyls crystal structure analysis DTA-TG.