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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, {2. Academy of sciences, Guangzhou 51064., china 2. Graduate University of {2. Academy of sciences, beijing 100039, china 3. SHRIMP isotope Laboratory, {2. Academy of Geological sciences, beijing 100037, china 4. institute of geology and geophysics, {2. Academy of sciences, beijing 10002., 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 {2. 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 (02.X-137) and southern (2.JH-10) Lincang batholith show the single and tight clusters on the concordia, and yield the weighted mean 2.6Pb/2.8U ages of 2.9.4.± 3.0 Ma and 2.0.4.± 3.6 Ma, respectively, representing the crystallized ages of these granites. The zircons for the rhyolitic sample (02.X-95) from the Manghuai Formation give a weighted mean 2.6Pb/2.8U age of 2.1.0 ± 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 (~2.0 Ma) and were originated from the postcollisional tectonic regime. An early Proterozoic 2.6Pb/2.8U apparent age of 1977±4. 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.

Analysis and application of automatic deformation monitoring data for buildings and structures of mining area

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中国有色金属学会会刊：英文版 2011年第S3期21卷 516-522页

作者： XIAO Jie1, 2. 3, ZHANG Jin4.1. institute of Geodesy and {2., chinese Academy of sciences, Wuhan 4.0077,{4. 2. Key Laboratory of Dynamic Geodesy, institute of Geodesy and {2., chinese Academy of sciences, Wuhan 4.0077,{4. 3. Graduate School of chinese Academy of sciences, beijing 10004.,{4. 4. Department of Surveying and Mapping, Taiyuan University of Technology, Taiyuan 03002.0}{4. institute of Geodesy and geophysics Chinese Academy of Sciences Wuhan 430077 China Key Laboratory of Dynamic Geodesy Institute of Geodesy and Geophysics Chinese Academy of Sciences Wuhan 430077 China Graduate School of chinese Academy of sciences Beijing 100049 China Department of Surveying and Mapping Taiyuan University of Technology Taiyuan 030024 China

The buildings and structures of mines were monitored automatically using modern surveying technology. Through the analysis of the monitoring data, the deformation characteristics were found out from three aspects containing points, lines and regions, which play an important role in understanding the stable state of buildings and structures. The stability and deformation of monitoring points were analysed, and time-series data of monitoring points were denoised with wavelet analysis and Kalman filtering, and exponent function and periodic function were used to get the ideal deformation trend model of monitoring points. Through calculating the monitoring data obtained, analyzing the deformation trend, and cognizing the deformation regularity, it can better service mine safety production and decision-making.

关键词： wavelet analysis Kalman filtering deformation monitoring data analysis mine

The features of gravity field and deep structure in western part of the South Yellow Sea

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chinese Science Bulletin 2000年第8期45卷 759-764页

作者： WANG Qianshen1 & AN Yulin1. institute of geophysics, {2. Academy of sciences, {4. 100101, china 2. {2. University of geology, {4. 100083, china institute of geophysics Chinesc Academy of Sciences Beijing China chinese University of geology Beijing China

The gravity data from the sea region to the west of 12.0} E of the South Yellow Sea have been processed and the feature of gravity fields analyzed. An experience relationship formula on the filter wavelength and corresponding depth has been put forward. Combined with the geological and seismic data, the deep tectonic framework and structural characters as well as possible favourable prospecting district for hydrocarbon in the South Yellow Sea have been discussed and analyzed.

关键词： western part of the South Yellow Sea gravity field deep structure.

^(4.)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 {2., beijing 100081,{4. 2. institute of geology, chinese Academy of Geological {2., beijing 100037,{4. 3. institute of geology and geophysics, chinese Academy of {2., beijing 10002.,{4. institute of Geomechanics Chinese Academy of Geological Sciences Beijing China institute of geology Chinese Academy of Geological Sciences Beijing China institute of geology and {2. 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, 4.Ar/39Ar dating, late Cenozoic.

Isotopic feature and uranium dating of the volcanic rocks in the Okinawa Trough

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中国科学：地球科学英文版 2006年第4期49卷 375-383页

作者： HUANG Peng1,2. LI Anchun1, HU Ningjing2.3, FU Yongtao1& MA Zhibang4.1. institute of Oceanology, {2. Academy of sciences, Qingdao 2.6071, china 2. Graduate School of the {2. Academy of sciences, beijing 100039, china 3. institute of Soil Science, {2. Academy of sciences, Nanjing 2.0008, china 4. institute of geology and geophysics, {2. Academy of sciences, beijing 10002., china institute of Oceanology Chinese Academy of Sciences Qingdao China Graduate School of the chinese Academy of sciences Beijing China institute of Soil Science Chinese Academy of Sciences Nanjing China institute of geology and {2. Chinese Academy of Sciences Beijing China

Volcanic rocks from the northern and middle Okinawa Trough were dated by ura- nium-series dating method. Differential fractions using magnetic procedure were designed to separate samples. New report on the ages and isotopic data of rocks in the northern trough (especially black pumice) was discussed. Based on the uranium dates and Sr-Nd isotopic ratio, magmatic evolution process of the Okinawa Trough was noted. Firstly, there have been wide silicic volcanic activities in the Okinawa Trough from late Pleistocene to present, and the volcanic rocks can be divided into three subgroups. Secondly, magma generally came from PREMA source area under the Okinawa Trough. Magmatic evolution in the northern trough was similar to the middle, but different to the south. Finally, volcanic activities indicated that opening of the southern Okinawa Trough did not happen due to the collision between Luson Arc and Eurasian Plate until the early Pleistocene.

关键词： Okinawa Trough, black pumice, uranium-series dating, Sr-Nd isotopic ratio, magmatic evolution.

The crustal structure under Sanjiang and its dynamic implications:Revealed by seismic reflection/refraction profile between Zhefang and Binchuan,Yunnan

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Science china Earth sciences 2005年第9期48卷 1329-1336页

作者： ZHANG Zhongjie1, BAI Zhiming1, WANG Chunyong2. TENG Jiwen1, Lü Qingtian3, LI Jiliang1, LIU Yifeng1 & LIU Zhenkuan4.1. institute of {2. and geophysics, chinese Academy of {4., beijing 10002., china 2. institute of geophysics, china Seismological Bureau, beijing 100085, china 3. institute of Deposition Resource, chinese Academy of Geo{4., beijing 100037, china 4. School of Exploration and Information, china University of Geo{4., beijing 100083, china institute of geology and {2. Chinese Academy of Sciences Beijing China institute of geophysics China Seismological Bureau Beijing China institute of Deposition Resource Chinese Academy of Geosciences Beijing China School of Exploration and Information China University of Geosciences Beijing China

The fault belts in Sanjiang mainly include Jinshajiang-Honghe fault, Lancangjiang fault and Nujiang fault (called Sanjiang faults) in western Yunnan Province, china. By interpreting the wide-angle seismic reflection/refraction profile between Zhefang and Binchuan, which crosses Tengchong and Baoshan blocks in Dianxi (western Yunnan) tectonic zone, we recon- struct the crustal structure with seismic traveltime tomography for crustal P-wave velocity and the seismic scattering image for crustal seismic reflection structure. In this paper, we firstly present the crustal structure images of P-wave velocity and seismic reflection under the wide-angle seismic profile. These results demonstrate that, the crustal velocity structure and seismic reflec- tion structure along the profile can be divided into 3 segments, and there is an obvious difference of crustal structure among the eastern, the western and the middle segment. Generally, crustal P-wave velocities in the Baoshan segment are 0.1―0.2.km/s slower and seismic reflection am- plitudes from Moho discontinuity are stronger than the other 2.segments. In the studied area, crustal thickness is about 4. km, and shows the thickening tendency from west to east along the profile. Additionally, it can be seen that there is one strong-amplitude seismic reflection event as bright points at the depths of 8―10 km, along the segment of 80―115 km of the profile (south- ward of Tengchong); and seismic reflection wave-field from Moho discontinuity varies obviously along the lateral direction. Finally, we make some discussions on the crustal thickening pattern in the Sanjiang fault belt, structural environment of earthquake development and the contact rela- tionship between the Tengchong block, Banshan block and Luxi trough.

关键词： Sanjiang area wide-angle seismic profile crustal structure.

Compositions of heavy minerals in Northeastern china sandlands and provenance analysis

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Science china Earth sciences 2007年第11期50卷 1715-1723页

作者： XIE Jing1,2.& DING ZhongLi1 1 institute of geology and {2., chinese Academy of {4., beijing 10002., china 2.Graduate University of chinese Academy of {4., beijing 10004., china institute of geology and {2. Chinese Academy of Sciences Beijing China Graduate University of chinese Academy of sciences Beijing China

Sand samples deposited since the Last Glacial Maximum (LGM) from the Hulun Buir, Horqin and Otin-dag sandlands were measured for their assemblages of heavy minerals and chemical compositions of detrital garnets and tourmalines. Heavy mineral assemblages of these three sandlands consist mainly of garnet, ilmenite, epidote and minor amphibole and magnetite. Garnets consist mainly of high Mg type-A ones (58% on average), and minor type-B ones. Toumalines are mainly composed of Mg-rich and minor Fe-rich ones. Compared with those of central-southern Mongolia and central Tarim, these three sandlands are derived from the Phanerozoic rocks of the Central Asian Orogenic Belt and the Archean and Paleoprotorozoic basement rocks of the North china Craton. Our results provide direct evidence that the present-day sands may be reworked from LGM ones. Differences of heavy mineral composi-tions occur between the samples of the three sandlands and Taklimakan Desert, indicating that the material of the western arid regions contributes little to the eastern sandlands.

关键词： heavy minerals,provenance,Northeastern china,garnet,tourmaline

Comparison of eastern paleo-Tethyan ophiolites and its geodynamic significance--Evidence from Dur'ngoi ophiolite

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Science china Earth sciences 2004年第4期47卷 378-384页

作者： CHEN Liang1,2. SUN Yong1,2. PEI Xianzhi2. Feng Tao2.& Zhang Guowei2.1. Open Laboratory of Continental Dynamics, Ministry of Education, Northwest University, Xi抋n 710069, china 2. institute of {2. and geophysics, {4. Academy of sciences, beijing 10002., china Open Laboratory of Continental Dynamics Ministry of Education Northwest University Xi’an China institute of geology and {2. Chinese Academy of Sciences Beijing China

Nd-Pb isotopic geochemistry of metabasalt from Dur抧goi ophiolite, Qinghai Prov-ince, NW china reveals the presence of DMM mixing with EMII components in its upper mantle source, which is comparable with present Indian MORB. Comparisons indicate that the geo-chemistry, chronology and source characteristics of Dur抧goi ophiolite coincide with Pa-leo-tethyan ophiolites from 揝anjiang?area. Together with evidences from regional geology in adjacent areas, this study proves that independent paleo-tethyan basins evolved contemporarily, the dynamics of which is attributed to the interaction of mantle plume with over-riding lithosphere.

关键词： ophiolite, Paleo-Tethys, DUPAL anomaly, Indosinian movement.

Fossil bacteria in Xuanlong iron ore deposits of Hebei Province

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Science china Earth sciences 2004年第4期47卷 347-356页

作者： DAI Yongding, SONG Haiming & SHEN Jiying institute of geology and {2., chinese Academy of {4.,beijing 10002., china institute of geology and {2. Chinese Academy of Sciences Beijing China

Discovered in Early Proterozoic Xuanlong iron ore deposits are six genera of fossil iron bacteria, i. e. sphere (coenobium of) rod-shaped (monomer) Naumanniella, ellipsoid elliptical Ochrobium,sphere spherical Siderocapsa and chain spherical Siderococcus, chain rod-shaped Leptothrix and Lieskeella, and six genera of fossil blue bacteria, namely sphere spherical Gloeocapsa, Synechocystis and Globobacter, chain spherical Anabaena and Nostoc, and con-strictive septate tubular Nodularia. The biomineralized monomers and coenobia of the two cate-gories of bacteria, together with hematite plates made up the bacteria pelletal, bacteria silky, bacteria fibrous and clasty bacteria pelletal textural lamina. The bacteria pelletal laminae com-bined with other bacteria laminae to make up oncolite, stromatolite and laminate. The precipita-tion of iron oxide was accelerated due to iron and blue bacteria cohabiting on microbial film or mat. The Xuanlong iron ore deposits are microbial binding ore deposits of ocean source.

关键词： iron and blue bacteria, bacteria textural lamina, microbial ore deposits, Late Early Proterozoic.