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Science china Earth {1. 2004年第9期47卷 794-803页

作者： ZHANG Yueqiao1, chen Wen2. 3 & yang Nong1 1. Institute of Geomechanics, {2. Academy of geological sciences, beijing 100081, china 2. Institute of geology, {2. Academy of geological sciences, beijing 100037, china 3. Institute of geology and Geophysics, {2. Academy of sciences, beijing 10002., china 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 (1.1.0 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.

Seismic multi-arch structures in East china

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Science china Earth {1. 2006年第2期49卷 133-146页

作者： yang {1. {2. zhide2.1.Institute of geology, chinese Academy of geological sciences, beijing 100037, china 2.Daqing Institute of Petroleum Exploration and Production, Daqing 1.371., china 1. Institute of geology Chinese Academy of Geological Sciences Beijing 100037 China 2. Daqing Institute of Petroleum Exploration and Production Daqing 163712 China

In previous papers (wencai, 2.02. 2.03), the author has analyzed the deep seismic reflection profiles along some of the Mesozoic plutons in East{1., and has pointed out that the crustal structures around these intrusions usually correlate with a special seismic fabric called the seismic multi-arch structure. This paper will continue to show main characteristics of the seismic multi-arch structures and discuss their relationship with mantle-origin magmatism and the lithospheric thinning process. Calibration of seismic reflectors in {2. continental drilling sites shows that small-scale arch-like reflectors can be generated by fractured eclogites or other plutons, they do not belong to the multi-arch structure specially discussed in the paper. The multi-arch structure is char-acterized by several arch-like reflectors distributed in both the upper and lower crust with granitoid plutons or stocks exposed on the surface, which do not have obvious negative Europium anomalies. Based on the distribution pattern of arch reflectors, the multi-arch magmatic structures can be divided into three main types, namely the simple vertical combination type, the spread arch magmatic struc-ture and the arch-bouquet structure. All of them correlate to mantle-origin magmatism, but occur in different places. The spread arch magmatic structures occur within a Mesozoic/Cenozoic rift zone with very thin and hot lithosphere. The vertical combination type of the multi-arch structures occurred near the rift zones where lithosphere was thin and hot. The arch-bouquet magmatic structures occur far from the rift zones where the lithosphere is not hot. The continental rifting acted as the late episode of the lithospheric thinning process seeing that the rift zones usually coincide with the thinnest parts of the lithosphere in East{1.. In different locations within the lithospheric thinning areas, mantle-origin magmatic activities have different characteristics, which might generate different

关键词： deep seismic reflection, multi-arch structure, eclogite bodies, mantle-origin magmatism, East china.

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 {1. 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,{2. 2. Institute of Geomechanics, chinese Academy of geological sciences, beijing 100081,{2. 3. beijing Center of SHRIMP, beijing 100037,{2. 4. Institute of geology, chinese Academy of geological sciences, beijing 100037,{2. 1. geological Surveying Institute of Hainan 570206 Haikou China 2. Institute of Geomechanics Chinese Academy of Geological Sciences 100081 Beijing China 3. beijing Center of SHRIMP 100037 Beijing China 4. Institute of geology Chinese Academy of Geological Sciences 100037 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 {1. 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.

Petrogenesis and dating of the Kangding complex,Sichuan Province

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Science china Earth {1. 2005年第5期48卷 622-634页

作者： chen Yuelong 1 , LUO Zhaohua 1 , ZHAO Junxiang, LI Zhihong, ZHANG Hongfei & SONG Biao 3 1. Faculty of Earth sciences and Natural Resources,{2. University of Geosciences, beijing 100083,{2. 2. Faculty of Earth sciences,{2. University of Geosciences, Wuhan 430074,{2. 3. beijing SHRIMP Center, Institute of geology, {12. Academy of geological sciences, beijing 100037,{2. 1. Faculty of Earth sciences and Natural Resources China University of Geosciences 100083 Beijing China 2. Faculty of Earth sciences China University of Geosciences 430074 Wuhan China 3. beijing SHRIMP Center Institute of Geology Chinese Academy of Geological Sciences 100037 Beijing China

An analysis of major and trace element geochemistry and SHRIMP U-Pb zircon dating of mafic, intermediate, and felsic rocks from the Mianning metamorphic complex of Si- chuan Province was conducted. One of our conclusions is that a majority of the zircons crystal- lized between 72.0}and 773 Ma in a magmatic regime. The complexes contain early to late Pa- leo-proterozoic relict zircons from ancient continental crust. The oldest age, 2.68 Ma, may rep- resent the basement of the yangtze block. Overgrowth zircon rims and palingenetic zircons have been observed and dated, and are believed to have formed after crystallization, during Paleozoic and Mesozoic metamorphic-anatexis. We also conclude that depletion of Nb, Ta, HREE, in a spider-diagram normalized to primitive mantle and calc-alkaline association, implies that they formed in island-arc or under-plating settings.

关键词： Kangding complex, zircons, SHRIMP, tectonic setting.

Re-Os(ICP-MS)dating of the massive sulfide ores from the Jinchuan Ni-Cu-PGE deposit

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Science china Earth {1. 2005年第10期48卷 1672-1677页

作者： yang Gang1.2. DU Andao1. LU Jiren3, QU Wenjun1.& {1. Jiangfeng2.1. National Research Center of Geoanalysis, beijing 100037, china 2. Laboratory for Earth Material Cycling, School of Earth and Space sciences, University of Science and Technology of china, Hefei 2.002., china 3. Institute of Mineral Resource, chinese Academy of {12. sciences, beijing 100037, china National Research Center of Geoanalysis beijing{1. Laboratory for Earth Material Cycling School of Earth and Space Sciences University of Science and Technology of China Hefei China Institute of Mineral Resource chinese Academy of {1. {2. beijing china

Massive sulfide ore from the Jinchuan Ni-Cu-PGE deposit was dated by Re-Os technique using Carius Tube digestion, Os distillation, Re extraction by acetone and ICP-MS measurement. An isochron giving an age of 833 ± 35 Ma, initial 1.7Os/1.8Os ratio of 0.2.9 ± 0.01. (MSWD = 1.7) and γOs = 1.0 ± 1. is obtained. The Re-Os age obtained agrees, within analytical uncertainties, with previous SHRIMP zircon U-Pb age of 82. ± 8 Ma (n=5, MSWD = 4.3). The result suggests that the deposit was formed at Neoproterozoic and that the formation of the Jinchuan Ni-Cu-PGE sulfide deposit may be closely related to the plume activity, which were attributed to the breakup of the Rodinia supercontinent. The high γOs of the massive ores sug-gests that crustal material was involved in the formation of the Jinchuan deposit, however, the quantity of the added crustal material is less than 1.%.

关键词： Jinchuan Ni-Cu-PGE deposit, Re-Os dating, ICP-MS.

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

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Science china Earth {1. 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, chinese Academy of {2. sciences, beijing 100037, china National Center of Rock and Mineral Analysis, chinese Academy of {2. sciences, beijing 100037, china Resource Assessment Center of Yunnan, Kunming 650011, china Institute of {12. and Geophysics, chinese Academy of sciences, beijing 100101, china chinese Academy of {2. sciences, beijing 100037, china 1. Institute of Mineral Resources Chinese Academy of Geological Sciences 100037 Beijing China 2. National Center of Rock and Mineral Analysis Chinese Academy of Geological Sciences 100037 Beijing China 3. Resource Assessment Center of Yunnan 650011 Kunming China 4. Institute of geology and Geophysics Chinese Academy of Sciences 100101 Beijing China 5. chinese Academy of {1. {2. 100037 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 33.9±1.1.Ma for the Machangqing deposit and 34.4±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 (35.4 Ma, 35.9 Ma, 36.2.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.

Northernmost paleo-tethyan oceanic basin in Tibet:Geo-chronological evidence from ^(40)Ar/^(39)Ar age dating of Dur'ngoi ophiolite

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chinese Science Bulletin 2001年第14期46卷 1203-1205页

作者： chen Liang, SUN Yong, PEI Xianzhi, GAO Ming, FENG Tao, ZHANG Zhongqing & chen Wen1. Laboratory of Continental Dynamics, Northwest University, Xi’an 710069,{2. 2. Department of geology, Northwest University, Xi’an, 710069,{2. 3. Institute of geology, chinese Academy of geological sciences, beijing, 100037,{2. Laboratory of Continental Dynamics Northwest University Xi’an China Department of geology Northwest University Xi’an China Institute of geology Chinese Academy of Geological Sciences Beijing China

Whole rock 40Ar/39Ar age dating has been conducted on a basalt sample from Dur’ngoi ophiolite, Qinghai Province, which was reported to be the northernmost pa-leo-tethyan oceanic basin in Tibet. A high temperature pla-teau age (345.3±7.9 Ma) with an isochorn age (336.6±7.1.Ma) has been obtained, representing the eruption time of oceanic crust Considering related geological settings, the new age provides constraints on the northernmost pa-leo-tethyan suture zone in Tibet and the tectonic evolution of Paleo-tethys in Northeast Tibet and adjacent areas.

关键词： Dur’ngoi ophlolite 40Ar -39Ar age Paleo-tethys.

Isotopic compositions of small shelly fossil Anabarites from Lower Cambrian in yangtze Platform of South{1.: Implications for palaeocean temperature

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Progress in Natural Science:Materials International 2007年第10期17卷 1185-1191页

作者： chen Yongquan1.2. Jiang Shaoyong1. Ling Hongfei1. {1. Jinghong1.and Wan Defan3(1. State Key Laboatory for Mineral Deposits Research and Center for Marine Geochemistry Research, Department of Earth sciences, Nanjing University, Nanjing 2.1}093, china 2. Tarim Oilfield Company Exploration & Development Research Institute, Ku’erle 841.00, china 3. Institute of Mineral Resources, {12. Academy of geological sciences, beijing 100037, china) State Key Laboatory for Mineral Deposits Research and Center for Marine Geochemistry Research Department of Earth Sciences Nanjing University Nanjing 210093 China arim Oilfield Company Exploration & Development Research Institute Ku’erle 841000 China Institute of Mineral Resources Chinese Academy of Geological Sciences Beijing 100037 China

Anabarites belong to small shelly fossils (SSF), which occur widely in the Lower Cambrian strata of yangtze Platform in South{1.. They are phosphate shell in composition and represent the earliest stage of the Cambrian bioradiation of Bilateria, the so-called "Cambrian Explosion". In this study, we attempted to separate Anabarites fossils from Lower Cambrian dolostones, and we obtained samples of both the fossils (SSF) and the granular phosphates (GP). Isotopic analyses were performed on samples of SSF, GP, and matrix dolostone (DH-2.). The results showed that the δ30Si values of the quartz filling in fossils celoms, and the siliceous materials in granular phosphates are -0.6‰ and -0.7‰, which is different from normal sedimentary siliceous rocks from the Lower Cambrian strata (0—0.7‰) as reported by Li et al., but is consistent with the data for siliceous rocks and cherts of submarine hydrothermal origin. It is likely that a later hydrothermal replacement could have taken place in the SSF-bearing sedimentary rocks. The oxygen isotope values of the phosphate of SSF and GP are 1..8‰ and 1..0‰, respectively. These are significantly higher than the Neoproterozoic phosphate ores (1..9‰—1..9‰) as reported by Ling et al., hence, late diagenesis and hydrothermal replacement may not have caused a significant change in the oxygen isotope compositions of the small shelly fossils, and the calculated temperatures (2..4—2..3℃) for palaeo-seawater using a SSF phosphate oxygen isotope thermometer are therefore considered here as the upper limit of seawater temperature in the Early Cambrian ocean of the yangtze Platform.

关键词： Anabarites oxygen isotope silicon isotope paleo-temperature.

Thrust Propagation in the Aqqikkol Lake Area, the East Kunlun Mountains, Northwestern china

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Acta Geologica Sinica(English Edition) 2003年第4期77卷 468-478页

作者： CUI Junwen, chen Wen, LI Pengwu, ZHANG Xiaowei and LI Li Institute of {1., {2. Academy of geological sciences, beijing 100037 Institute of geology Chinese Academy of Geological Sciences Beijing 100037

The western segment of the East Kunlun Mountains is one of the poorly studied regions in northwestern china. Through a structural analysis of the typical sections, we have the following views: (1. There is a very well developed fault system in the western segment of the East Kunlun Mountains and thrust propagation, normal slip and decoupling are the chief deformation events in this area. (2. Although the thrusting started in the Late Carboniferous and Late Triassic-Early Jurassic, strong activity took place in the Miocene-Quaternary when the Kumkol basin was strongly downwarped. (3) The tectonic pattern of coexistence of N-directed thrust propagation and S-directed normal slip in this area is consistent with the general tectonic pattern of the northern Qinghai-Tibet plateau and also very similar to that of the Himalayan region on the southern margin of the Qinghai-Tibet plateau, but their directions between the thrust propagation are opposite and all the strong thrust propagations occurred from the Miocene-Pliocene to Quaternary, a period featuring strong collision between the Indian plate and the Eurasian plate and abrupt uplift of the Qinghai-Tibet plateau. This oppositely directed thrust propagation and normal slip reveal such kinematic characteristics as symmetric propagations of deep-seated materials towards the north and south beneath the Qinghai-Tibet plateau and gravitational sliding of superficial materials towards the interior of the plateau. Therefore, the establishment of the fault system in the study area may provide an approach to the study of deep processes of the northern Qinghai-Tibet plateau and the construction of a unified geodynamic model for the uplift of the Qinghai-Tibet plateau.

关键词： western segment of the East Kunlun Mountains thrust propagation normal slip plate collision dynamic model

Wave tectono-sedimentary processes in Tarim basin

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Science china Earth {1. 2005年第11期48卷 1949-1959页

作者： JIN Zhijun1.2. ZHANG Yiwei1.& {2. Shuping1.1. Key Laboratory for Hydrocarbon Accumulation, Ministry of Education,{1. University of Petroleum, beijing 1.2.49,{1. 2. Exploration and Production Research Institute,{1. Petroleum & Chemical Corporation, beijing 1.0083,{1. 1. Key Laboratory for Hydrocarbon Accumulation Ministry of Education China University of Petroleum 102249 Beijing China 2. Exploration and Production Research Institute China Petroleum & Chemical Corporation 100083 Beijing China

Based on the unconformities, the formation times of structures, and geological wave filtering applied to basin fills of typical wells around the Manjiaer area in the Tarim basin, the wave tectono-sedimentary processes in the Tarim Basin are discussed. The results of geological wave filtering of basin fills of typical wells show that, in time domain, the evolution of the Tarim basin was controlled by various wave processes with the periods of 740±Ma, 2.0±Ma, {2.0±Ma and 30±Ma. The analyses of basin fills, basin subsidence and unconformities show that the trends of the sedimentary facies belts, depocenters, and centers of subsidence migrated and interchanged periodically with periods of 2.0±Ma. These show the propagation of wave movements in space domain. The wave evolution of the Tarim basin is of significance to understanding the formation of the oil and gas reservoirs in the basin.

关键词： Tarim basin, tectonics, sedimentation, crustal undation, wave evolution