维普中文期刊产品整合服务
321篇 您的检索式:作者名="ZHIQIN"
    题名 作者 年代 出处 被引量
1Uplift of the Longmen Shan range and the Wenchuan earthquake显示文摘Zhiqin Xu Shaocheng Ji Haibing Li Liwei Hou Xiaofang Fu Zhihui Cai 2008Episodes2008,31,3:106
2A Review of Modular Multilevel Converters显示文摘模块组合多电平变换器(modular multilevel converter,MMC)具有高度模块化、易于扩展、输出电压波形好等特点,尤其适用于中高压大功率系统应用。首先介绍MMC的电路拓扑和工作原理,总结MMC的主要技术特点;然后分别回顾MMC在脉冲调制、直流电压控制、预充电、环流、谐波、数学模型、主电路参数设计、故障保护等关键问题的最新研究进展,以及其在电力传动、电能质量问题治理领域的工程应用现状,在此基础上指出MMC今后亟待研究的关键问题。相关研究结果表明,MMC在电力系统中有广泛的应用前景,是未来中高压大功率系统,尤其是高压输电技术的重要发展方向。YANG Xiaofeng LIN Zhiqin ZHENG Trillion Q. YOU Xiaojie 2013中国电机工程学报2013,33,6:99
3Water-Saving and High-Yielding Irrigation for Lowland Rice by Controlling Limiting Values of Soil Water Potential显示文摘现在的学习调查了一个灌溉系统是否能被建立节省水和增加谷物产量在灌溉低地大米(Oryza sativa L.) 在领域水平由合适的用水管理提高水生产率。用二地成年的米饭栽培变种,二个灌溉系统;常规灌溉和节省水的灌溉,被进行。在节省水的灌溉系统,限制与特定的生长阶段有关的土壤水潜力的价值作为灌溉索引被建议。与排水在在哪儿的常规灌溉相比在另外的时间,增加的谷物在 7.4% ~ 11.3% 产出的节省水的灌溉,在 24.5% ~ 29.2% 的减少的灌溉用水,和增加的水生产率中间季节、充满(谷物每灌溉用水的立方的米让步) 在 43.1% ~ 50.3% 。节省水的灌溉显著地增加了产量指数,改进 milling 和外观质量,在根流血提高了玉米素 + 玉米素核糖甙集中并且提高了在谷物的蔗糖 synthase,腺苷 diphosphateglucose pyrophosphorylase,淀粉 synthase 和淀粉分叉酶的活动。我们的结果由控制限制根和谷物,还原剂水输入,和增加谷物的生理的活动产出的与阶段能提高的特定的生长有关的土壤水潜力的价值显示那节省水的灌溉。Jianchang Yang Kai Liu Zhiqin Wang Yong Du Jianhua Zhang 2007Journal of Integrative Plant Biology2007,49,10:46
4The ages of U-Pb and Sm-Nd for eclogite from the western segment of Altyn Tagh tectonic belt——Evidence for existence of Caledonian orogenic root显示文摘The eclogites of Altyn Tagh tectonic belt occur as lens within gneisses characterized by amphibolite-facies mineral parageneses. The well-preserved eclogite is selected for Sm-Nd and U-Pb isotopic dating. The Sm-Nd isotopic data yield a whole rock-garnet-omphacite isochron of (500 ?10) Ma. The U-Pb isotopic measurements of zircons show that the fourJianxin Zhang Zeming Zhang Zhiqin Xu Jingsui Yang Junwen Cui 1999Chinese Science Bulletin1999,44,24:46
5Ages and Compositions of the Precambrian High-grade Basement of the Qilian Terrane and Its Adjacent Areas显示文摘Based on geological, chronological, geochemical and Nd isotopicstudies of the high-grade basement of the Qilian terrane, the authors have drawn the following main conclusions: (1) the high-grade basement of the Qilian terrane consists mainly of meta-argillo-arenaceous rocks and granites and its bulk part was formed in the period of 0.8-1.0 Ga (the Jinningian period); (2) most of the meta-argillo-arenaceous rocks and granitic rocks have strong negative Eu and Ba anomalies (Eu/Eu*= 0.47-0.71 and Ba/Ba*= 0.16-0.64), with tDM and εNd (1.0 Ga) ranging from 1.87 to 2.26 Ga and from -8.54 to -4.06 respectively, showing relatively high maturity; and (3) the Jinningian granitic rocks are a typical product of continent-continent collision, being probably related to the formation of the supercontinent Rodinia. These studies, com bined with the study of high-grade basement rocks near the Qilian terrane, suggest that before the Jinningian period, the Qilian-Qaidam northern-margin terrane and Dunhuang-Alxa terrane were separated from each other, belonging to differ ent plate systems of the North China craton and Yangtze platform respectively. The Qilian orogenic belt was the same as or similar to the Qiling orogenic belt in terms of the geological evolution history at least before the Jinningian period.WAN Yusheng, XU Zhiqin, YANG Jingsui and ZHANG Jianxin Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037 2001Acta Geologica Sinica(English Edition)2001,75,4:40
6Evidence for UHP metamor-phism of eclogites from the Altun Mountains显示文摘Ultrahigh pressure (UHP) metamorphism refers to metamorphism that has occurred at pressures for the stability of coesite. The polycrystalline quartz inclusions showing the characteristic texture within garnets of eclogites indicates the pre-existence of coesites under the peak meta-morphic condition. The unusual exsolution textures in om-pacites and apatites, and the pressure estimations of phengite-bearing eclogites have been taken to provide further proof of eclogite formation under the UHP conditions. Combined with the fact that coesites have been observed in country rocks of eclogites in North Qaidam Mountains, another UHP metamorphic belt cut by the large-scale strike-slip fault in the Altun-North Qaidam area of China is confirmed.Jianxin Zhang Jingsui Yang Zhiqin Xu Fancong Meng Haibing Li Rendeng Shi 2002Chinese Science Bulletin2002,47,9:33
7Discovery of eclogite at northern margin of Qaidam Basin,NW China显示文摘Eclogite was first discovered at the northern margin of the Qaidam Basin in this study. It occurs as pods in the gneiss sequence of Middle to Upper Proterozoic age and is mainly composed of garnet, omphacite, phengite and rutile. The garnets contain 44%-62% of almandine, 15%-33% of grossular and 12%-30% of pyrope molecules, and the omphacites contain 40%-46% of jadeite. Applying garnet_clinopyroxene thermometry and jadeite geobarometry, the peak conditions of eclogite facies metamorphism occurred at about (722±123)℃ and at the pressure of up to c. 22 ×10 8 Pa.Jingsui Yang Zhiqin Xu Haibing Li Cailai Wu Junwen Cui Jianxin Zhang Wen Chen 1998Chinese Science Bulletin1998,43,20:34
8Grain quality changes and responses to nitrogen fertilizer of japonica rice cultivars released in the Yangtze River Basin from the 1950s to 2000s显示文摘While the yield potential of rice has increased but little is known about the impact of breeding on grain quality, especially under different levels of N availability. In order to investigate the integrated effects of breeding and N levels on rice quality 12 japonica rice cultivars bred in the past60 years in the Yangtze River Basin were used with three levels of N: 0 kg N ha-1, 240 kg N ha-1,and 360 kg N ha-1. During the period, milling quality(brown rice percentage, milled rice percentage, and head rice percentage), appearance quality(chalky kernels percentage, chalky size, and chalkiness), and eating and cooking quality(amylose content, gel consistency, peak viscosity, breakdown, and setback) were significantly improved, but the nutritive value of the grain has declined due to a reduction in protein content. Micronutrients, such as Cu, Mg, and S contents, were decreased, and Fe, Mn, Zn, Na, Ca, K, P, B contents were increased. These changes in grain quality imply that simultaneous improvements in grain yield and grain quality are possible through selection. Overall, application of N fertilizer decreased grain quality, especially in terms of eating and cooking quality. Under higher N levels, higher protein content was the main reason for deterioration of grain quality, although lower amylose content might contribute to improving starch pasting properties. These results suggest that further improvement in grain quality will depend on both breeding and cultivation practices, especially in regard to nitrogen and water management.Junfei Gu Jing Chen Lu Chen Zhiqin Wang Hao Zhang Jianchang Yang 2015The Crop Journal2015,3,4:25
9The Origin and Tectonic Significance of the Volcanic Rocks of the Yeba Formation in the Gangdese Magmatic Belt, South Tibet显示文摘Zircon U-Pb geochronology, Hf isotope and whole-rock geochemistry were performed on the tuffs of the Yeba Formation in the Gangdese magmatic belt, South Tibet. The results are used to detail the age, source nature and tectonic processes that led to the formation of the Gangdese belt. Dating results indicate that the rhyolitic-andesitic tuffs were formed at 174–170 Ma. Positive and variable zircon ε_(Hf)(t) values of the rhyolitic tuffs reveal that the source was dominated by juvenile material, however, experienced crustal contamination. The basaltic tuffs have low HREEs, high contents of compatible elements(V and Cr) and no Eu anomaly. In contrast, the rhyolitic-andesitic tuffs show low compatible trace elements, depletion in Eu but enrichment in incompatible elements(Rb, Zr and Hf). According to the discrimination diagrams of P_2O_5-SiO_2 and Th-Rb, the rhyolitic-andesitic tuffs show a close affinity to Ⅰ-type granitoids. Moreover, these tuffs are marked by significant depletion in Nb, Ta and Ti, plotted in calc-alkaline field, and with the andesitic-rhyolitic tuffs falling into an active continental margin setting. We suggest that these tuffs of the Yeba Formation were probably generated in an active continental margin above the northward subduction of the Neo-Tethyan oceanic lithosphere.Xuxuan Ma Zhiqin Xu Xijie Chen Joseph G.Meert Zhenyu He Fenghua Liang Yuanku Meng Shiwei Ma 2017Journal of Earth Science2017,28,2:20
10The Zoulang Nanshan Caledonian Subduct ion Complex in the Northern Qilian Mountains and Its Dynamics显示文摘The front of the Zoulang Nanshan Caledonian volcanic island arc zone in the northern Qilian Mountains is a forearc accretionary terrane, composed of multiple accretionary volcanic island arcs, flysch accretionary wedges,high-pressure metamorphosed detachment zones and remnants of ophiolites. It resulted from the northeastward subduction of the Early Palaeozoic Qilan oceanic crust beneath the Alxa block. High-pressure metamorphism, which occurred during the subduction, progressed through three stages: the initial stage of medium T-high P,the main stage of temperature decrease and pressure increase, and the lag stage of pressure decrease and temperature increase. Finally the paper presents a retrotrench subduction dynamic model indicative of northward subduction of the central Qilian block and southward accretion of the Alxa block during the period of 450-500 Ma.Xu Zhiqin, Xu Huifen, Zhang Jianxin, Li Haibing, Zhu Zhizhi, Qu Jingchuan,Institute of Geology, Chinese Academy of Geological Sciences, BeijingChen Daizhang, Chen Jinlu, China University of Geosciences, Beijingand Yang KaichunNo. 2 Q ilian Geological Party, Bureau of Geology and Mineral Resources of Q inghai Province, Q ilian County, Q inghai 1994Acta Geologica Sinica(English Edition)1994,68,3:19
11Geological and chronological evidence of Indo-Chinese strike-slip movement in the Altyn Tagh fault zone显示文摘A set of granitic and amphibole mylonite are exposed in the Altyn Tagh fault zone. The preliminary study shows that these rocks are the product of the syntectonic anatexis in the process of the left-lat- eral strike-slip shear, and are the result of the ductile transpression. There are two types of zircon sorted from the mylonite formed with syn-shear anatexis. Among them, one is the anatectic long co-lumnar zircon and another is the residual metamorphic sub-rounded columnar zircon. Two groups of age for single zircon measured by ion microprobe (SHRIMP) are obtained: one is 461-547 Ma for the sub-rounded columnar residual metamorphic zircon, and the other is 239-244 Ma for the long-columnar anatectic zircon. This type of zircon is direc-tionally spread in rock, and the long axis direction of its crystal is identical to that of stretching lineation, represent-ing the direction of tectonic stress in the process of the strike-slip. 40Ar-39Ar age of the directional growth horn-blende in the same myloniteLI Haibing YANG Jingsui XU Zhiqin WU Cailai WAN Yusheng SHI Rendeng Juhn G.Liou P.Tapponnier Trevor R.Ireland 2002Chinese Science Bulletin2002,47,1:18
12Vision,application scenarios,and key technology trends for 6G mobile communications显示文摘With the global commercialization of the fifth-generation(5G)network,many countries,including China,USA,European countries,Japan,and Korea,have started exploring 6G mobile communication network,following the tradition of“planning the next while commercializing one generation”.Currently,studies on 6G networks are at the infancy stage.Research on the vision and requirements for 6G is still ongoing,and the industry is yet to clarify the key enabling technologies for 6G.However,6G will certainly build on the success of 5G.Therefore,developing high-quality 5G networks and seamlessly integrating 5G with verticals are the priorities before 2030,when 6G is projected to be commercialized.Also,global 5G standards will keep evolving to better support vertical applications.As a milestone,the Third-Generation Partnership Project(3GPP)published Release 16 in July 2020,which continuously enhanced the capabilities of mobile broadband service based on Release 15 and realized the support for low-delay and high-reliability applications,such as Internet of Vehicles and industrial Internet.Currently,3GPP is working on Releases 17 and 18,focusing on meeting the demands of medium-and high-data-rate machine communication with low-cost and high-precision positioning,which will be published in June 2022.Thus,6G networks will further expand the application fields and scope of the Internet of Things to accommodate those services and applications that are beyond the capabilities of 5G networks.Herein,we present our vision,application scenarios,and key technological trends for 6G networks.Furthermore,we propose several future research opportunities in 6G networks with regard to industrialization and standardization.Zhiqin WANG Ying DU Kejun WEI Kaifeng HAN Xiaoyan XU Guiming WEI Wen TONG Peiying ZHU Jianglei MA Jun WANG Guangjian WANG Xueqiang YAN Jiying XIANG He HUANG Ruyue LI Xinhui WANG Yingmin WANG Shaohui SUN Shiqiang SUO Qiubin GAO Xin SU 2022Science China(Information Sciences)2022,65,5:17
13Late Triassic Granites From the Quxu Batholith Shedding a New Light on the Evolution of the Gangdese Belt in Southern Tibet显示文摘The Gangdese magmatic belt formed during Late Triassic to Neogene in the southernmost Lhasa terrane of the Tibetan plateau. It is interpreted as a major component of a continental margin related to the northward subduction of the Neo-Tethys oceanic slab beneath Eurasia and it is the key in understanding the tectonic framework of southern Tibet prior to the India-Eurasia collision. It is widely accepted that northward subduction of the Neo-Tethys oceanic crust formed the Gangdese magmatic belt, but the occurrence of Late Triassic magmatism and the detailed tectonic evolution of southern Tibet are still debated. This work presents new zircon U-Pb-Hf isotope data and whole-rock geochemical compositions of a mylonitic granite pluton in the central Gangdese belt, southern Tibet. Zircon U-Pb dating from two representative samples yields consistent ages of 225.3±1.8 Ma and 229.9±1.5 Ma, respectively, indicating that the granite pluton was formed during the early phase of Late Triassic instead of Early Eocene(47–52 Ma) as previously suggested. Geochemically, the mylonitic granite pluton has a sub-alkaline composition and low-medium K calc-alkaline affinities and it can be defined as an I-type granite with metaluminous features(A/CNK<1.1). The analyzed samples are characterized by strong enrichments of LREE and pronounced depletions of Nb, Ta and Ti, suggesting that the granite was generated in an island-arc setting. However, the use of tectonic discrimination diagrams indicates a continental arc setting. Zircon Lu-Hf isotopes indicate that the granite has highly positive εHf(t) values ranging from +13.91 to +15.54(mean value +14.79), reflecting the input of depleted mantle material during its magmatic evolution, consistent with Mg~# numbers. Additionally, the studied samples also reveal relatively young Hf two-stage model ages ranging from 238 Ma to 342 Ma(mean value 292 Ma), suggesting that the pluton was derived from partial melting of juvenile crust. Geochemical discrimination diagrams also suggest that the granite was derived from partial melting of the mafic lower crust. Taking into account both the spatial and temporal distribution of the mylonitic granite, its geochemical fingerprints as well as previous studies, we propose that the northward subduction of the Neo-Tethys oceanic slab beneath the Lhasa terrane had already commenced in Late Triassic(~230 Ma), and that the Late Triassic magmatic events were formed in an active continental margin that subsequently evolved into the numerous subterranes, paleo-island-arcs and multiple collision phases that form the present southern Tibet.MENG Yuanku XU Zhiqin XU Yang MA Shiwei 2018Acta Geologica Sinica(English Edition)2018,92,2:16
14Unusual high-density and saline aqueous inclusions in ultrahigh pressure metamor- phic rocks from Sulu terrane in eastern China显示文摘Primary high-density fluid inclusions were identified in garnet from ultrahigh pressure eclogite in the southern part of the Sulu terrane. They occur isolatedly or in cluster together with relatively low-density two-phase inclu-sions. The eutectic temperature of the inclusions is as low as ≤ -52℃. A bubble was nucleated in a liquid inclusion dur-ing the specific stage of cyclic cooling-heating runs, and the liquid-gas homogenization temperature was measured to be ≤-12.5℃. The composition of the inclusions modeled by the system CaCl2-NaCl-H2O, yields the fluid density of 1.27g/cm3 that corresponds to a pressure of ca. 2.4 GPa at thetemperature of peak eclogite-facies metamorphism, close tothe ultrahigh pressure metamorphic conditions. During theexhumation of the eclogite the inclusions reacted with thehost mineral, forming hydrous silicate minerals that resulted in lowering of the fluid density and its transformation to multi-phase inclusions.SHEN Kun ZHANG Zeming A.M.van den Kerkhof XIAO Yilin XU Zhiqin J.Hoefs 2003Chinese Science Bulletin2003,48,18:14
15Hybrid graphene metasurfaces for highspeed mid-infrared light modulation and single-pixel imaging显示文摘During the past decades,major advances have been made in both the generation and detection of infrared light;however,its efficient wavefront manipulation and information processing still encounter great challenges.Efficient and fast optoelectronic modulators and spatial light modulators are required for mid-infrared imaging,sensing,security screening,communication and navigation,to name a few.However,their development remains elusive,and prevailing methods reported so far have suffered from drawbacks that significantly limit their practical applications.In this study,by leveraging graphene and metasurfaces,we demonstrate a high-performance free-space mid-infrared modulator operating at gigahertz speeds,low gate voltage and room temperature.We further pixelate the hybrid graphene metasurface to form a prototype spatial light modulator for high frame rate single-pixel imaging,suggesting orders of magnitude improvement over conventional liquid crystal or micromirror-based spatial light modulators.This work opens up the possibility of exploring wavefront engineering for infrared technologies for which fast temporal and spatial modulations are indispensable.Beibei Zeng Zhiqin Huang Akhilesh Singh Yu Yao Abul K.Azad Aditya D.Mohite Antoinette J.Taylor David R.Smith Hou-Tong Chen 2018Light(Science & Applications)2018,7,1:13
16High- and Ultrahigh-pressure Metamorphism and Retrogressive Textures of Gneiss in the Donghai Area——Evidence from gneisses in drillhole ZK2304显示文摘In the gneisses from the drillhole ZK2304 of the Donghai area, there have been preserved high- and ultrahigh-pressure metamorphic mineral assemblages, a series of complicated retrogressive textures and relevant metamorphic reactions. In addition to garnet, jadeititic-clinopyroxene and rutile, other peak stage (M2) minerals in some gneisses include phengite, aragonite and coesite or quartz pseudomorphs after coesite. The typical peak-stage mineral assemblages in gneisses are characterized by garnet + jadeitic-clinopyroxene + rutile + coesite, garnet + jadeitic-clinopyroxene + phengite + rutile ± coesite and garnet + jadeitic-clinopyroxene + aragonite + rutile ± coesite. The grossular content (Gro) in garnet is high and may reach 50. 1 mol%. The SiO2 content of phengite ranges from 54.37% to 54.84% with 3.54-3.57 p.f.u. Quartz pseudomorphs after coesite occur as inclusions in garnet.The gneisses of the Donghai area have been subjected to multistage recrystallization and exhibit a closewise P-TLIU Fulai, XU Zhiqin, XU Huifen and YANG Jingsui Institute of Geology, CAGS, 26 Baiwanzhuang Rd., Beijing 100037 Zhu Xiling 1999Acta Geologica Sinica(English Edition)1999,73,3:12
17Mineral inclusions of zircon and UHP metamorphic evidence from paragneiss and orthogneiss of pre-pilot drill-hole CCSD-PP2 in north Jiangsu Province,China显示文摘Coesite inclusions, together with omphacite, jadeite, garnet and phengite inclusions, were identified in zircons separates from almost all gneissic core samples of pre-pilot drillhole CCSD-PP2 by the Laser Raman spectros-copy and the cathodoluminescence method. These data indicate that gneissic rocks consisting of paragneisses and or-thogneisses ubiquitously experienced UHP metamorphism. This research may be of great significance for an in-depth study of the subduction-exhumation mechanism of the Sulu UHP metamorphic belt and selecting the drilling site for the Chinese Continental Scientific Drilling Project.LIU Fulai XU Zhiqin YANG Jingsui S Maruyama J.G.Liou I.Katayama H.Masago 2001Chinese Science Bulletin2001,46,12:12
18Projection micro stereolithography based 3D printing and its applications显示文摘Projection micro stereolithography(PμSL)is a high-resolution(up to 0.6μm)3D printing technology based on area projection triggered photopolymerization,and capable of fabricating complex 3D architectures covering multiple scales and with multiple materials.This paper reviews the recent development of the PμSL based 3D printing technologies,together with the related applications.It introduces the working principle,the commercialized products,and the recent multiscale,multimaterial printing capability of PμSL as well as some functional photopolymers that are suitable to PμSL.This review paper also summarizes a few typical applications of PμSL including mechanical metamaterials,optical components,4D printing,bioinspired materials and biomedical applications,and offers perspectives on the directions of the further development of PμSL based 3D printing technology.Qi Ge Zhiqin Li Zhaolong Wang Kavin Kowsari Wang Zhang Xiangnan He Jianlin Zhou Nicholas X Fang 2020International Journal of Extreme Manufacturing2020,2,2:11
19Neoproterozoic–Early Paleozoic Tectonic Evolution of the South China Craton: New Insights from the Polyphase Deformation in the Southwestern Jiangnan Orogen显示文摘A >1500–km–long northeast–southwest trending Neoproterozoic metamorphic belt in the South China Craton(SCC) consists of subduction mélange and extensional basin deposits. This belt is present under an unconformity of Devonian–Carboniferous sediments. Tectonic evolution of the Neoproterozoic rocks is crucial to determining the geology of the SCC and further influences the reconstruction of the Rodinia supercontinent. A subduction mélange unit enclosed ca.1000–850–Ma mafic blocks, which defined a Neoproterozoic ocean that existed within the SCC, is exposed at the bottom of the Jiangnan Orogen(JO) and experienced at least two phases deformation. Combined with new(detrital) zircon U–Pb ages from metasandstones, as well as igneous rocks within the metamorphic belt, we restrict the strongly deformed subduction mélange as younger than the minimum detrital age ca. 835 Ma and older than the ca. 815 Ma intruded granite. Unconformably overlying the subduction mélange and the intruded granite, an intra–continental rift basin developed <800 Ma that involved abundant mantle inputs, such as mafic dikes. This stratum only experienced one main phase deformation. According to our white mica ^(40)Ar/^(30)Ar data and previously documented thermochronology, both the Neoproterozoic mélange and younger strata were exhumed by a 490–400–Ma crustal–scale positive flower structure. This orogenic event probably induced the thick–skinned structures and was accompanied by crustal thickening, metamorphism and magmatism and led to the closure of the pre–existing rift basin. Integrating previously published data and our new results, we agree that the SCC was located on the periphery of the Rodinia supercontinent from the Neoproterozic until the Ordovician. Furthermore, we prefer that the convergence and dispersal of the SCC were primarily controlled by oceanic subduction forces that occurred within or periphery of the SCC.ZHAO Zhongbao XU Zhiqin MA Xuxuan LIANG Fenghua GUO Peng 2018Acta Geologica Sinica(English Edition)2018,92,5:11
20Petrology of the Non-mafic UHP Metamorphic Rocks from a Drillhole in the Southern Sulu Orogenic Belt,Eastern-Central China显示文摘The Drillhole ZK703 with a depth of 558 m is located in the Donghai area of the southern Sulu ultrahigh-pressure (UHP) metamorphic belt, eastern China, and penetrates typical UHP eclogites and various non-mafic rocks, including peridotite, gneiss, schist and quartzite. Their protoliths include ultramafic, mafic, intermediate, intermediate-acidic, acidic igneous rocks and sediments. These rocks are intimately interlayered, which are meters to millimeters thick with sharp and nontectonic contacts, suggesting in-situ metamorphism under UHP eclogite facies conditions. The following petrologic features indicate that the non-mafic rocks have experienced early-stage UHP metamorphism together with the eclogites: (1) phengite relics in gneisses and schists contain a high content of Si, up to 3.52 p.f.u. (per formula unit), while amphibolite-facies phengites have considerably low Si content (<3.26 p.f.u.); (2) jadeite relics are found in quartzite and jadeitite; (3) various types of symplectitic coronas and pseudomorphs after omphacite, jadeite, kyanite and phengite occur extensively in gneisses, schists and quartzites; (4) polycrystalline quartz pseudomorphs after coesite occur as inclusions within garnet of gneisses and schists; (5) coesite, jadeite and omphacite inclusions are found in zircons of gneiss and amphibolite from an adjacent drillhole. Geological, petrological and geochemical data indicate that large volumes of crustal material was buried to depths possibly exceeding 100 km and then exhumed to the Earth's surface.ZHANG Zeming, XU Zhiqin and XU HuifenInstitute of Geology, Chinese Academy of Geological Sciences, 26 Baiwanzhuang Rd., Beijing 100037 E-mail: zzm@ccsd.org.cn. 2003Acta Geologica Sinica(English Edition)2003,77,2:11
返回顶部 每页显示:
共17页 首页 上一页 第1页 下一页 末页 /17 跳转

网站首页 | 关于我们 | 联系我们 | 产品服务 | 客服中心 | 广告服务 | 版权声明 | 网站联盟 | 友情链接 | 售卡网点

版权所有© 渝B2-20050021-1 渝公网安备 50019002500403号 违法和不良信息举报中心

互联网出版许可证 新出网证(渝)字10号 全国400电话 - 免长途话费