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| 1 | 宜昌中堡岛新石器时代遗址显示文摘中堡岛(又名松苞岛、中包岛)位于长江西陵峡境三斗坪镇(因建葛洲坝该镇已拆迁)西1公里许,四周为砂石堆积的河漫滩,中部隆起而平缓,其上竹树葱笼,远视如一座堡垒,故名。全岛东西长约1000、南北宽300—400米,西端隔茅坪溪与秭归县茅坪镇相望,南侧近山,中隔一条宽约数十米的江汊;北临长江(图一;图版壹,1)。 | The Yichang Prefectural Museum, Hubei Province, and the Department of History, Sichuan University | 1987 | 考古学报1987,,1: | 55 |
| 2 | Influence of the impounding process of the Three Gorges Reservoir up to water level 172.5m on water eutrophication in the Xiangxi Bay显示文摘The water level of the Three Gorges Reservoir(TGR) rose to 172.5 m in two stages from September to November,2008.The hydrodynamic parameters and water quality parameters(e.g.flow velocity,temperature,turbidity and nutrient content) had been continuously monitored to reveal the influence of the impounding process of the TGR on the water eutrophication in the Xiangxi Bay(XXB).The maximal daily rise of the water level of the TGR was about 2.38 m.The water exchange between the mainstream(the Changjiang River) and the XXB of the TGR was enhanced by density current,and its main characteristics were a density-stratified flow in different directions.The water exchange reduced the differences of the water quality parameters(for example,temperature,turbidity,nutrient level,pH,etc.) between the mainstream and the XXB during the impounding process.Meanwhile,the water stability index in the mainstream remained small but it was lowered in the XXB.The main causes included the dilution by water of lower concentration of the chlorophyll a(Chl.a) entering from the mainstream,the decline of the water stability,and the increase of suspended silt,which induced the Chl.a to decrease in the XXB during the impounding process.The grade of the water eutrophication changed from middle eutrophic level to mesotrophic state in the process.However,as available nutrients were imported into the XXB from the mainstream during the impounding process the risk of water eutrophication increases in the XXB in the future. | YANG ZhengJian1,LIU DeFu1,JI DaoBin1,2 & XIAO ShangBin1,3 1 College of Civil & Hydroelectric Engineering,China Three Gorges University,Yichang 443002,China 2 School of Water Resources & Hydropower Engineering,Wuhan University,Wuhan 430072,China 3 Institute of Earth Environment,Chinese Academy of Sciences,Xi’an 710075,China | 2010 | Science China(Technological Sciences)2010,53,4: | 58 |
| 3 | Characteristics of one-year observation of VOCs,NOx, and O_3 at an urban site in Wuhan, China显示文摘A continuous online observation of ozone and its precursors(NOx, VOCs) was carried out in central urban Wuhan from September 2016 to August 2017. The concentration levels of ozone,NOx, VOCs and their variations in urban Wuhan were analyzed, as well as effects of VOCs on ozone photochemical generation and the main controlling factors for ozone production. During the observation period, the average concentrations of ozone and NOx in Wuhan was 22.63 and30.14 ppbv, respectively, and the average concentration of VOCs was 32.61 ppbv(42.3% alkanes,13.0% alkenes, 10.0% aromatics, 7.3% acetylene, 9.9% OVOCs, and 10.5% halohydrocarbons).Ozone concentration was higher in spring and summer as compared with autumn and winter,wheras VOCs and NOx concentratios were lower in spring and summer but higher in autumn and winter. Aromatics and alkenes, two of VOCs species, showed the highest contributions to ozone formation potential in Wuhan(35.7% alkenes, 35.4 aromatics, 17.5% alkanes, 8.6% OVOCs,1.6% halogenated hydrocarbons, and 1.4% acetylene). Among all VOCs species, those with the highest contribution were ethylene, m-xylene, toluene, propylene and o-xylene. The contribution of these five compounds to the total ozone formation potential concentration was 43.90%.Ozone-controlling factors in Wuhan changed within one day; during the early morning hours(6:00–9:00), VOCs/NOx was low, and ozone generation followed a VOCs-limited regime.However, during the peak time of ozone concentration(12:00–16:00), the ratio of VOCs/NOx was relatively high, suggesting that ozone generation followed a NOx-limited regime. | Yichang Yang Xingang Liu Jun Zheng Qinwen Tan Miao Feng Yu Qu Junling An Nianliang Cheng | 2019 | Journal of Environmental Sciences2019,31,5: | 26 |
| 4 | Age of Yingfeng rapakivi granite pluton on the north flank of Qaidam and its geological significance显示文摘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 (526 281) 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. | XIAO Qinghui1,2, LU Xinxiang1,3, WANG Fei4, SUN Yangui5, WEI Xiangdong3 & XING Zuoyun6 1. Division of Granite Geology, China Geological Survey, Yichang 443003, China 2. Information Center of Ministry of Land and Resources, Beijing 100812, China 3. Geological Survey of Henan Province and Institute of Geological Research of Henan Province, Zhengzhou 450053, China 4. Geological Institute, China Seismological Bureau, Beijing 100029, China 5. Geological Survey Institute of Qinghai Province, Xining 810032, China 6. China University of Geosciences, Wuhan 430074, China | 2004 | Science China Earth Sciences2004,47,4: | 20 |
| 5 | Discontinuous deformation analysis based on complementary theory显示文摘The contact between blocks is treated by the open-close iteration in the conventional discontinuous deformation analysis (DDA),which needs to introduce spurious springs between two blocks in contact and to assume the normal stiffness and the tangential stiffness (the penalty factors). Unreasonable values of stiffness would result in numerical problems. To avoid the penalty factors and the open-close iteration,we reformulate the DDA as a mixed complementary problem (MiCP) and then choose the path Newton method (PNM) to solve the problem. Some examples including those originally designed by Shi are reanalyzed,which proves feasibility of the proposed procedure. | ZHENG Hong1,2 & JIANG Wei2 1 China Three Gorges University,Key Laboratory of Geological Hazards on Three Gorges Reservoir Area,Ministry of Education, Yichang 443002,China 2 State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430071,China | 2009 | Science China(Technological Sciences)2009,52,9: | 15 |
| 6 | Visible light-induced N-doped TiO_2 nanoparticles for the degradation of microcystin-LR显示文摘N-doped nano-crystalline TiO2 powders have been synthesized by the sol-gel method.The shape and crystal structure of the resulting N-doped TiO2 were investigated by X-ray Photoelectron Spectroscopy (XPS),X-ray spectroscopy (XRD),Transmission Electron Microscopy (TEM) and UV-vis reflection spectrum.The results showed that doping TiO2 with nitrogen can lower its band gap and apparently shift its optical response to the visible region.Under the visible light (λ> 420 nm) irradiation,the MC-LR was degraded by the synthesized N-TiO2 nano-material.The variation of MC-LR amount and its intermediates were detected by high performance liquid chromatography (HPLC) and LC-MS,respectively.The mineralization of MC-LR was determined by total organic carbon (TOC) analysis.Simultaneously,transient oxidative species generated during photocatalysis were tracked by electron spin resonance (ESR) and Peroxidase method.All these results indicated that visible-light excited N-TiO2 can activate molecular oxygen and thereby achieve degradation of MC-LR completely within 14 h.The removal of 59% of TOC was achieved after 20 h irradiation.The major oxidative species in the system were hydroxyl radical (·OH) and H2O2.13 Kinds of intermediates were primarily identified in the process.Based on these results,a reasonable conclusion was drawn for the degradation of MC-LR wherein its four positions are easy to be attacked by the photo-generated OH radical followed by the hydrolyzation of peptides. | YANG Jing,CHEN DengXia,DENG AnPing,FANG YanFen,LUO GuangFu,LI DeJiang,LI RuiPing & HUANG YingPing Alan G.MacDiarmid Research Institute of Renewable Energy,China Three Gorges University,Yichang 443000,China | 2010 | Science China Chemistry2010,53,8: | 12 |
| 7 | ^(207)Pb/^(206)Pb Zircon Dating of the Huangtuling Hypersthene-Garnet-Biotite Gneiss from the Dabie Mountains, Luotian County, Hubei Province, China: New Evidence for Early Precambrian Evolution显示文摘The Huangtuling hypersthene-garnet-biotite gneiss at Luotian County, Hubei Provine, is a typicalgranulite-facies rock of the Dabie Group Complex in the Dabie orogenic belt. Investigations on the morphology andoccurrence of zircons and their internal structures shown in the thin sections lead to the recognition of three types ofzircons, which are in good agreement with the types identified on the basis of morphology, colour and external fea-tures from the related zircon concentrates. The observation of zircons in the rock reveals that part of type 1 zirconsshow signs of a double-layered structure. The interval part existed in the protolith prior to the granulite-facies meta-morphism. Type 2, the prismatic zircons which mainly occur in garnet and hypersthene are metamorphic minerals ofthe granulite-facies metamorphism. Type 3, the round multifaceted zircons in felsic minerals and biotite, are proba-bly attributed to a later geological event related to migmatization. The 207Pb/206Pb zircon dating by direct evaporationon (thermal evaporation ion mass spectrometer) yields ages ranging from 2814 Ma to 1992 Ma. The age discrepancyamong these different zircon types is conspicuous. The yellow-brown(type 1) zircons give ages of 2814±29 Ma to2527±6 Ma, the prismatic euhedral zircons (type 2), 2456±7 Ma to 2254±4 Ma, and the round multifaceted zircons(type 3), 1992±10 Ma. The results are geologically interpreted in consideration of the complicated behaviours of zir-cons during Precambrian geological evolution of the Dabie area. (1) If the protolith of the gneiss is a sedimentaryrock, then type 1 zircons are clastic ones and the ages 2814±29 Ma and 2811±27 Ma may reflect the minimum age ofthe rocks of its source region. also the first geological event in the area. Sedimentation of the protolith occurred be-tween 2814 Ma and 2527 Ma, probably close to 2814 Ma. If the protolith is a volcanic rock, then the formation age ofthe supracrustal rocks of the Dabie Group Complex is around 2814 Ma. The age 2456±7 Ma reflects the time whenthe granulite-facies metamorphism took place. The later migmatization event is dated at aboat 1992±10 Ma, and isprobably the latest early Precambrian event in the area. The present work provides geochronological evidence for the existence of the Dabie Archaean craton, whichhad probably experienced 3 or 4 geological events during its early Precambrian evolution. | JIAN Ping YANG Weiran and ZHANG Zichao Institute of Geology,CAGS,26 Baiwanzhuang Rd, Beijing 100037 China University of Geosciences, Wuhan, Hubei 430074 Yichang Institute of Geology and Mineral Resources, CAGS, Yichang, Hubei 443003 | 1999 | Acta Geologica Sinica(English Edition)1999,73,1: | 12 |
| 8 | Coupling analysis of unsteady seepage and stress fields in discrete fractures network of rock mass in dam foundation显示文摘The drag force of water flow through single fracture and the coupling characteristics of seepage and stress in single fracture surface are analyzed,and a three dimensional model of coupled unsteady seepage and stress fields is proposed.This model is used to the analysis of foundation rock mass of a high dam.If the coupling effects are considered,the changes of boundary heads have less influence on the inner head of rock mass,and the strong permeability of main fractures appears.If the coupling effects are not considered,the fractures distribution affects the inner head more greatly.When the upstream water head declines,the inner head of dam foundation slightly declines and the hydraulic gradient distribution becomes smoother.A bigger upstream water level declining velocity has a stronger lag effect,meanwhile the values of stress components change more greatly.Therefore the upstream water level declining velocity directly affects the stability of rock mass in dam foundation and we should take into account the above factors to make sure the safety of the dam during reservoir level fluctuation period. | CHAI JunRui 1,2 & XU WeiSheng 2 1 College of Hydraulic and Environmental Engineering,China Three Gorges University,Yichang 443002,China 2 College of Hydropower Engineering,Xi’an University of Technology,Xi’an 710048,China | 2011 | Science China(Technological Sciences)2011,54,S1: | 11 |
| 9 | Re-Os dating of magnetite from the Shaquanzi Fe-Cu deposit,eastern Tianshan,NW China显示文摘Magnetite separates from the Shaquanzi Fe-Cu deposit in the eastern Tianshan are used for Re-Os geochronological study.Re-Os data show that magnetite separates contain ca.0.7 to 50.9 ppb Re and ca.16 to 63 ppt Os.Eight samples yield a model 3isochron age of(303±12)Ma(2),which is within uncertainty consistent with of the Re-Os date(295±7 Ma)of associated pyrite.Tectonic evolution shows that the Late Carboniferous Aqishan-Yamansu belt was a back-arc rift.Therefore,the Re-Os age of ca.300 Ma indicates that the Shaquanzi Fe-Cu deposit may have formed in a back-arc extensional environment and was closely related to mantle-derived magmatism.The successful application of Re-Os magnetite geochronology in the Shaquanzi Fe-Cu deposit suggests that the purity of magnetite,relatively high Re and Os contents,and the closure of Re-Os systematic are base factors for a successful Re-Os geochronology.There would be a good prospect for Re-Os geochronology for magnetite. | HUANG XiaoWen QI Liang WANG YiChang LIU YingYing | 2014 | Science China Earth Sciences2014,57,2: | 11 |
| 10 | Ecological hydrograph based on Schizothorax chongi habitat conservation in the dewatered river channel between Jinping cascaded dams显示文摘Hydropower development changes the river hydrological regime,thereby altering river ecosystem significantly.One important measure for reducing degradation of ecosystem is to determine ecological flow and implement it by reservoir operation.This paper described a method to calculate river ecological flow based on fish habitat conservation and applied it to Jinping River Bend of Yalong River.Schizothorax chongi was selected as target species,and the fish habitat model coupling with water environmental model was developed according to the relationship between fish and water environment factors.Moreover,improved hydraulic habitat suitability index(IHHS) and habitat fragment index(HFI) varying with discharge were discussed in this paper.Habitat area representing average annual flow was taken as a reference,and then ecological hydrographs under different habitat conservation levels were calculated considering season variation and life stages of fish.Compared to the natural condition,the model results indicated that the reservoir operation clearly influenced the habitat of the target fish.It was proposed to ensure flow releases to maintain 70%-90% habitat in section after joint while about 60% before joint. | LI RuoNan 1,CHEN QiuWen 1,2 & Duan Chen 1,3 1 Research Center for Eco-environmental Science,Chinese Academy of Sciences,Beijing 100085,China 2 China Three Gorges University,Yichang 443002,China 3 Hydraulics Department,Changjiang River Scientific Research Institute,Wuhan 430010,China | 2011 | Science China(Technological Sciences)2011,54,S1: | 10 |
| 11 | Metamorphosed mafic rocks with N-type MORE geochemical features in Hainan Island-Remnants of the Paleo-Tethys Oceanic Crust?显示文摘A number of metamorphosed mafic rocks occurred within the Paleozoic strata in the Chenxing and Bangxi regions at the northern side of the Changjiang-Qionghai Fault in Central Hainan Island. These metamorphosed mafic rocks are tholeiites in chemistry. They are characterized by extreme depletion of Th, Nb, Ta and LREEs, resembling the depleted N-type mid-ocean ridge basalts (MORE). Field relations suggest that the protolith of the metamorphosed mafic rocks were likely formed in Paleozoic. These metamorphosed mafic rocks with N-type MORB geochemical features were probably the remnants of the Paleo-Tethys oceanic crust. | LI Xianhua, ZHOU Hanwen, DING Shijiang, LEE Chi-yu, ZHANG Renjie, ZHANG Yeming & GE Wenchun1. Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China 2. Hainan Geological Survey, Haikou 570206, China 3. Department of Geology, Taiwan University, Taipei 106-17, China 4. Yichang Institute of Geology and Mineral Resources, Chinese Academy of Geological Sciences, Yichang 443003, China | 2000 | Chinese Science Bulletin2000,45,10: | 9 |
| 12 | Oxidation-Induced C--H Functionalization: A Formal Way for C--H Activation显示文摘 | Yichang Liu Hong Yi Aiwen Lei | 2018 | Chinese Journal of Chemistry2018,36,8: | 8 |
| 13 | Genesis of Yangla Banded Skarn-Hosted Copper Deposit in Tethys Orogenic Belt of Southwestern China显示文摘INTRODUCTIONTheYanglacopperdepositishostedbybandedskarn,whichwastraditionalyconsideredtohavebeenformedbycontactmetasomaticpro... | Zhan Mingguo Lu Yuanfa Yichang Institute of Geology and Mineral Resources, CAGS, Yichang 443003 Dong Fangliu Department of Geology and Mineral Resources, China University of Geosciences, Beijing 100083 Chen Kaixu Wei Junqi Yichang Institute of | 1999 | Journal of Earth Science1999,18,1: | 6 |
| 14 | Rotary-scaling fine-tuning (RSFT) method for optimizing railway wheel profiles and its application to a locomotive显示文摘The existing multi-objective wheel profile optimization methods mainly consist of three sub-modules:(1)wheel profile generation,(2)multi-body dynamics simulation,and(3)an optimization algorithm.For the first module,a comparably conservative rotary-scaling finetuning(RSFT)method,which introduces two design variables and an empirical formula,is proposed to fine-tune the traditional wheel profiles for improving their engineering applicability.For the second module,for the TRAXX locomotives serving on the Blankenburg–Rubeland line,an optimization function representing the relationship between the wheel profile and the wheel–rail wear number is established based on Kriging surrogate model(KSM).For the third module,a method combining the regression capability of KSM with the iterative computing power of particle swarm optimization(PSO)is proposed to quickly and reliably implement the task of optimizing wheel profiles.Finally,with the RSFT–KSM–PSO method,we propose two wear-resistant wheel profiles for the TRAXX locomotives serving on the Blankenburg–Rubeland line,namely S1002-S and S1002-M.The S1002-S profile minimizes the total wear number by 30%,while the S1002-M profile makes the wear distribution more uniform through a proper sacrifice of the tread wear number,and the total wear number is reduced by 21%.The quasi-static and hunting stability tests further demonstrate that the profile designed by the RSFT–KSM–PSO method is promising for practical engineering applications. | Yunguang Ye Yayun Qi Dachuan Shi Yu Sun Yichang Zhou Markus Hecht | 2020 | Railway Engineering Science2020,28,2: | 6 |
| 15 | 宜昌地区钩端螺旋体病的流行特点显示文摘为探索二十多年宜昌地区钩端螺旋体病(简称钩体病)的流行规律,提供预防的科学依据,我们综合历年的流行病学资料,对宜昌地区钩体病的流行病学特点探讨如下: | Pan Huiming,Antiepidemie Station of Yichang Area,Hubei Province | 1986 | 中国公共卫生学报1986,,2: | 5 |
| 16 | Run by Run Control of Time-pressure Dispensing for Electronics Encapsulation显示文摘To alleviate the influence of gas compressibility on the process performance of time-pressure dispensing for electronics encapsulation, a predictive model is developed based on power-law fluid to estimate the encapsulant amount dispensed. Based on the simple and effective model, a run by run (RbR) supervisory control scheme is delivered to compensate the variation resulting from gas volume change in the syringe. Both simulation and experiment have shown that the dispensing consistency has been greatly improved with the model-based RbR control strategy developed in this paper. | Cong-Ping Chen~(1,*) Han Ding~2 1 College of Mechanical & Materials Engineering, China Three Gorge University, Yichang 443002, PRC 2 School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, PRC | 2008 | International Journal of Automation and computing2008,5,4: | 5 |
| 17 | Anisotropic damage coupled modeling of saturated porous rock显示文摘It is widely acknowledged that the natural rock mass is anisotropic and its failing type is also non-isotropic. An orthotropic elastic damaged model has been proposed in which the elastic deformation,the damaged deformation and irreversible deformation can be identified respectively. A second rank damage tensor is employed to characterize the induced damage and damage evolution related to the propagation conditions of microcracks. A specific form of the Gibbs free energy function is used to obtain the effective elastic stiffness and the limited scopes of damage parameters are suggested. The model’s parameter determination is proposed by virtue of conventional tri-axial test. Then,the proposed model is developed to simulate the coupled hydraulic mechanical responses and traction behaviors in different loading paths of porous media. | LU YingFa1,2, WU XinXing1,2 & SHAO JianFu3 1 Key Laboratory of Geological Hazards on Three Gorges Reservoir Area, Ministry of Education, China Three Gorges University, Yichang 443002, China 2 School of Civil Engineering, Wuhan University, Wuhan 430071, China 3 University of Sciences and Technologies of Lille, Lille 59655, France | 2010 | Science China(Technological Sciences)2010,53,10: | 5 |
| 18 | THE APPLICATIONS AND STUDY OF NUMERICAL SIMULATION OF TURBULENCE FLOW WITH FREE SURFACE IN HYDRAULIC SPILL WAYS STRUCTURE显示文摘The turbulence flow Free Surface has important applications in hydraulic spillways structure,such as the hydraulic jump,energy dissipation flow etc.This is being considered as very complicated flow,and has not yet been solved quite well by numerical method. In this paper,a Large-scale computational software package are developed for numerical laboratory of hydraulic spillway structure.Some methods,such as turbulence model, free surface and irregular boundary treating techniques,scientific computer visualization are put forward and performed. | Dai Hui-chaoChina Yangtze Three Gorges Project Development Corporation,Yichang 443002,P. R.China | 1997 | Journal of Hydrodynamics1997,9,4: | 5 |
| 19 | Enhanced permeation performance of polyether-polyamide block copolymer membranes through incorporating ZIF-8 nanocrystals显示文摘Membrane-based CO_2 separation is a promising alternative in terms of energy and environmental issues to other conventional techniques. Polyether-polyamide block copolymer(Pebax) membranes are promising for CO_2 separation because of their excellent selectivity, but limited by their moderate gas permeability. In this study,fresh-prepared zeolitic imidazolate framework-8(ZIF-8) nanocrystals were integrated into the Pebax?1657matrices to form mixed matrix membranes. The resulting membrane exhibits significantly improved CO_2permeability(as high as 300% increase), without the sacrifice of the selectivity, to the pristine polymer membrane. Several physical characterization techniques were employed to confirm the good interfacial interaction between ZIF-8 fillers and Pebax matrices. The effect of added ZIF-8 fillers on the transport mechanism through MMMs is also explored. Mixed-gas permeation for both CO_2/N_2 and CO_2/CH_4 was also evaluated. The separation performance for CO_2/CH_4 mixtures on the ZIF-8/Pebax MMMs is very close to the Roberson upper bound, and thus is technologically attractive for purification of natural gas. | Longwei Xu Long Xiang Chongqing Wang Jian Yu Lixiong Zhang Yichang Pan | 2017 | Chinese Journal of Chemical Engineering2017,25,7: | 5 |
| 20 | Isotopic Geochronological Evidence for the Caledonian Xiongdian Eclogite in the Northwestern Dabie Mountains,China显示文摘A typical HP/MT (high pressure/medium temperature) eclogite from Xiongdian, northwestern Dabie Mountains, has been geochronologically studied using the single-zircon U-Pb, 40Ar-39Ar and Sm-Nd methods. Prismatic zircons occurring as inclusions within garnets define a minimum crystallization age of 399.5±1.6 Ma. 40Ar-39Ar dating on amphibole gives a plateau age.of 399.2 ± 4 Ma, which is interpreted as a retrogression age of amphibolite facies. This integrated study enables us to conclude that the age of high-pressure metamorphism is older than 399.5 ± 1.6 Ma, suggesting Caledonian collision between the North China and Yangtze plates. Round zircon within the aggregate of quartz and muscovite gives a concordant age of 301± 2 Ma, reflecting a later retrogression event. An age profile of post-eclogite metamorphism is documented, including amphibolite facies metamorphism at 399.2 Ma shortly after eclogitization and later retrogressive metamorphism at 301 Ma. Sm-Nd mineral isochron of garnet+omphacite | Jian PingYichang Institute of Geology and Mineral Resources. CAGS, Yichang City,Hubei Province 443003Yang Weiran China University of Geosciences, Wuhan, HubeiLi Zhichang Yichang Institute of Geology and Mineral Resources, CAGS, Yichang, HubeiZhou Huifang Tianjin Instutite of Geology and Mineral Resources, CAGS, Tianjin Zhu Xiling | 1997 | Acta Geologica Sinica(English Edition)1997,71,4: | 4 |