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铅芯叠层橡胶支座基础隔震结构双向地震反应分析 被引量:16
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作者 王建强 管品武 姚谦峰 《地震工程与工程振动》 CSCD 北大核心 2005年第1期133-137,共5页
本文对铅芯叠层橡胶支座双向耦合恢复力模型进行了改进,采用基础隔震结构动力分析程序DABIS对铅芯叠层橡胶支座基础隔震结构进行了单向及双向地震反应对比分析。结果表明,在单向和双向地震作用下,基础隔震结构的加速度反应和位移反应较... 本文对铅芯叠层橡胶支座双向耦合恢复力模型进行了改进,采用基础隔震结构动力分析程序DABIS对铅芯叠层橡胶支座基础隔震结构进行了单向及双向地震反应对比分析。结果表明,在单向和双向地震作用下,基础隔震结构的加速度反应和位移反应较为接近,但在双向地震作用下,支座的最大位移明显大于单向地震作用时的支座最大位移,因而在确定支座最大位移时应考虑双向地震作用的影响。 展开更多
关键词 铅芯叠层橡胶支座 恢复力模型 基础隔震结构 双向地震反应 dabis
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Petrology of Eclogite at Huwan,Western Dabie and Implications for Phase Equilibrium Modeling on LT-HP/UHP Eclogite
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作者 Bin Xia Ying Cui +1 位作者 Yunfeng Shang Jingtao Shi 《Journal of Earth Science》 2025年第3期1018-1032,共15页
Phase equilibrium modeling using internally consistent thermodynamic dataset and associated activity-composition(a-x)models are very helpful for quantifying P-T evolution for eclogite,which is the basis for decipherin... Phase equilibrium modeling using internally consistent thermodynamic dataset and associated activity-composition(a-x)models are very helpful for quantifying P-T evolution for eclogite,which is the basis for deciphering the geodynamic processes in subduction zones.In this study,we apply different versions of datasets(ds55 and ds62)and associated a-x relations to a wellestablished LT-HP eclogite at Huwan in the classic western Dabie orogen to constrain its P-T evolution.The eclogite comprises garnet+omphacite+amphibole+white mica+epidote+quartz+chlorite+rutile/ilmenite/sphene.Garnet porphyroblasts show mono-variation in the end members(spessartine from 17 mol%to 0,pyrope from 2 mol%to 18 mol%,almandine from 47 mol%to 64mol%and grossular from 35 mol%to 18 mol%)from core to rim.Phase diagrams combined with compositional isopleth thermobarometry show that dataset ds62 and associated a-x relations yield P_(max)of~33 kbar at~560℃,conflicting with our petrological observations and previous studies.On the other hand,phase equilibrium modeling using dataset ds62 and a revised symmetric garnet a-x model irrespective of Fe^(3+)(O)gives P_(max)of~27 kbar at~560℃,consistent with the results using dataset ds55 and associated a-x relations.Therefore,we recommend a symmetric model for garnet involving py,alm,gr and spss,without Fe~(3+)components,instead of the asymmetric garnet a-x relations involving py,alm,gr,spss and kho by White et al.(2014),for calculating phase diagrams for LT-(U)HP eclogite when using dataset ds62.In this study,the defined P-T path is characterized by a segment of the prograde evolution showing a first moderate slope,followed by gentle then steep slopes,representing the thermal structure evolution recorded by slab surface during continental subduction.Our work combined with previous studies conclude that in western Dabie,the Huwan HP eclogite belt to the north and the Hong'an HP eclogite belt to the south belong to the same HP slice overlying the Xinxian UHP slice. 展开更多
关键词 phase equilibrium modeling LT-HP eclogite continental subduction western Dabie garnets PETROLOGY
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Origins of Two Types of Serpentinites from Hong'an,Western Dabie Orogen,Central China and Associated Fluid/Melt-Rock Interactions:Implications from Geochemistry and Mineralogy
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作者 Yuchen Liu Changqian Ma 《Journal of Earth Science》 2025年第3期992-1017,共26页
A cluster of serpentinite bodies has been recognized tectonically emplaced within the greenschist-amphibolite-facies metamorphic terrane in Hong'an,western Dabie orogen,central China.Two types of serpentinites are... A cluster of serpentinite bodies has been recognized tectonically emplaced within the greenschist-amphibolite-facies metamorphic terrane in Hong'an,western Dabie orogen,central China.Two types of serpentinites are identified on the basis of integrated petrographic,mineralogical and geochemical study.The first type,represented by Yinshanzhai serpentinite complex(Group 1)comprises heterogeneous lithology as a massive serpentinite matrix“intruded”by antigoriteenriched serpentinite lenses.They are both pseudomorphic textured with different mineral assemblages indicating an increasing temperature-pressure condition.Serpentinite matrix(Group 1a)is chemically characterized by high MgO/SiO_(2)and low Al_(2)O_(3)/SiO_(2),Ti and Ca contents,suggesting a depleted mantle wedge origin.The coexistence of compositionally-heterogeneous chromite with highCr^(#)(0.78-0.96)and intermediate-Cr^(#)(0.59-0.70)pristine cores indicates extensive mantle melting.Meanwhile,extremely high Fo olivine relicts(96-97)with considerably higher MnO and lower NiO contents than mantle olivine indicate that they are metamorphic products from serpentine decomposition.Accordingly,we propose that Yinshanzhai serpentinite complex experienced two distinct episodes of hydration.The serpentinite lenses(Group 1b)show higher SiO_(2)and lower MgO concentrations.Nevertheless,the trace elements of groups 1a and 1b are consistent:U-shaped REE patterns,positive Eu anomalies and enrichment of LILE(i.e.,Cs,U)are all identified as forearc properties.They are affected by reducing slab-derived fluids in forearc mantle,with f_(O2)of 1 to 2 logarithmic units below f_(O2)of fayalite-magnetite-quartz buffer(FMQ-2~FMQ-1).The second type is antigorite-serpentinites(Group2)represented by Ximaoshan and Wangchunwan blocks.They are non-pseudomorphic,with no primary framework silicate surviving.Fertile compositions(i.e.,higher Al_(2)O_(3)and Al_(2)O_(3)/SiO_(2),nearly flat REE patterns)and conjoint enrichment of LILE with HFSE suggest melt/rock interaction.Negative Ce,Eu anomalies,and enriched U relative to alkaline elements demonstrate interactions with more oxidized seawater or seafloor fluids(FMQ~FMQ-1).Remarkable Sr negative anomalies may be attributed to Sr release during lizardite/antigorite transition in subduction zone,indicating interaction with low-Sr slab fluids.We propose that Group 2 serpentinites originate either from mantle wedge or abyssal peridotites,refertilized by mantle melts,then hydrated in seafloor or shallow forearc and entrapped into subduction channel.Combined with geochronology and tectonic constraints of associated eclogites in Hong'an terrane,the two types of serpentinites may correlate with subduction of different oceanic basins during the late Paleozoic and/or Proterozoic eras.It raises possibility of defining an ophiolitic setting in Hong'an Orogen for which further evidence is required. 展开更多
关键词 SERPENTINITES orogenic peridotites western Dabie chromite fluid/melt-rock interaction GEOCHEMISTRY MINERALOGY
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Unraveling multidimensional land transfers in mountainous areas:influence of grassroots governance,geographic location,livelihood capital,and demographic factors
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作者 XU Yinan WANG Weiwen WANG Ying 《Journal of Mountain Science》 2025年第2期611-635,共25页
Cropland abandonment has been a widespread phenomenon in mountainous areas due to the increasing number of natural disasters and the massive migration of rural labor in the process of rapid urbanization.Land transfer ... Cropland abandonment has been a widespread phenomenon in mountainous areas due to the increasing number of natural disasters and the massive migration of rural labor in the process of rapid urbanization.Land transfer is a crucial prerequisite for ensuring food security and fostering rural revitalization.How to promote land transfer in mountainous areas remains a challenging but important task.Nevertheless,there is a dearth of research examining land transfers among farm households that specifically address mountainous regions,and the influence of grassroots governance and geographic location has not been thoroughly elucidated within this particular context.Based on 895household samples collected in Dabie Mountainous Area in China,this study employs binary and ordinal logistic regression models to provide a more comprehensive analysis on land transfers among rural households and the determinants,including the decision to transfer land,the existence of land transfer rents,the channel of land transfer,the duration of the transfer,the pre-transfer cultivation situation,and the level of satisfaction with the land transfer rent.The findings reveal that grassroots governance,geographic location,livelihood capital,and demographic factors significantly influence land transfers among rural households.Specifically,villagers'public participation positively affects land transfer participation(β=0.235,p<0.05),while the operation of village rules and regulations negatively impacts it(β=-0.296,p<0.05).Village cadre satisfaction positively influences both land transfer rent(β=0.274,p<0.05)and rent satisfaction(β=0.303,p<0.05).Improved civil relations in the village correlate with lower land transfer rent(β=-0.511,p<0.05),while a better social atmosphere is associated with higher satisfaction with transfer rent(β=0.575,p<0.01).Households at higher elevations tend to prefer government-mediated land transfers with longer durations.The distances to the township and county centers have contrasting effects on land transfer rent,but their impacts on participation in land transfer,choice of transfer channel,and duration are consistent.The study also found that different types of livelihood capital,as well as the demographic characteristics of households,significantly affect various aspects of land transfer.These empirical findings can inform policymaking to promote more efficient land transfers in mountainous region. 展开更多
关键词 Land transfer Grassroots governance Geographic location Livelihood capital Demographic factors Dabie Mountainous Area China
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Unveiling the role of social networks: Enhancing rural household livelihood resilience in China's Dabie Mountains
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作者 TANG Lanyun LIU Chongchong WANG Ying 《Journal of Geographical Sciences》 2025年第2期335-358,共24页
Social networks are vital for building the livelihood resilience of rural households.However,the impact of social networks on rural household livelihood resilience remains em-pirically underexplored,and most existing ... Social networks are vital for building the livelihood resilience of rural households.However,the impact of social networks on rural household livelihood resilience remains em-pirically underexplored,and most existing studies do not disaggregate social networks into different dimensions,which limits the understanding of specific mechanisms.Based on 895 household samples collected in China's Dabie Mountains and structural equation modeling,this paper explored the pathway to enhance livelihood resilience through social networks by dis-aggregating it into five dimensions:network size,interaction intensity,social cohesion,social support,and social learning.The results indicate that:(1)Livelihood assets,adaptive capacity and safety nets significantly contribute to livelihood resilience,whereas sensitivity negatively affects it.Accessibility to basic services has no significant relationship with livelihood resilience in the study area.(2)Social networks and their five dimensions positively impact livelihood re-silience,with network support having the greatest impact.Therefore,both the government and rural households should recognize and enhance the role of social networks in improving liveli-hood resilience under frequent disturbances.These findings have valuable implications for mitigating the risks of poverty recurrence and contributing to rural revitalization. 展开更多
关键词 livelihood resilience social network rural revitalization structural equation modeling Dabie Mountains China
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Magmatic Processes of the Lingshan Granitic Batholith in the Dabie Orogen,Central China:Insights into Dabie-Type Porphyry Mo Mineralization
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作者 Jiang Zhu Zhanke Li +5 位作者 Guohu Wang Xianbin Shi Yang Wang Chao Chen Song Chen Yuanbing Zou 《Journal of Earth Science》 2025年第5期2075-2093,共19页
Dabie-type porphyry Mo deposits were proposed as a new type of porphyry Mo deposits,and had unique geological characteristics.It is still poorly understood about the magmatic processes that led to the Dabie-type Mo mi... Dabie-type porphyry Mo deposits were proposed as a new type of porphyry Mo deposits,and had unique geological characteristics.It is still poorly understood about the magmatic processes that led to the Dabie-type Mo mineralization.Here,we present zircon U-Pb and Lu-Hf isotopic,whole-rock and biotite elemental,and whole-rock Sr-Nd isotopic analyses on the Lingshan granitic batholith in the Dabie Orogen.It consists of three units(ⅠtoⅢ)that were emplaced before,genetically accompanied with,and after the Mo mineralization.LA-ICP-MS zircon U-Pb dating yielded crystallization ages of 128.2±1.0 Ma(MSWD=1.14)for UnitⅠand ages of 127.8±1.2 Ma(MSWD=0.28)and 126.6±1.8 Ma(MSWD=1.6)for UnitⅡ,indicating that they were emplaced during 130 to 125 Ma.The granites have high SiO_(2)contents(75.84 wt.%to 78.94 wt.%)and low MgO contents(0.07 wt.%to 0.10 wt.%),and are classified as fractionatedⅠ-type granite.UnitsⅠandⅡhave similar Sr-Nd isotopic ratios(ε_(Nd)(t)=-16.2 to-17.2,(^(87)Sr/^(86)Sr)_(i)=0.70540 to 0.70692)and zirconε_(Hf)(t)values(-17.4 to-20.4),indicating they were derived from partial melting of the ancient Yangtze lower crust.Mo mineralized granite from UnitⅡis characterized by the lower oxygen fugacity,fluorine enrichment and high fractionation.Magmas of unitsⅠandⅡhave experienced fractional crystallization,with the assimilation of supracrustal materials that account for the increased TiO_(2),F and Mo contents,and the decreased fO_(2).We proposed that the assimilation in upper-crustal magmatic processes plays key factors for magmatic systems that led to the Dabie-type porphyry Mo deposits. 展开更多
关键词 granite crustal assimilation oxygen fugacity porphyry Mo deposit Dabie Orogen mineral deposits
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大别山高压-超高压片麻岩锆石的拉曼光谱学研究 被引量:3
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作者 刘文元 刘景波 《岩石学报》 SCIE EI CAS CSCD 北大核心 2009年第9期2157-2164,共8页
对大别山高压-超高压片麻岩的锆石进行了激光拉曼探针、阴极发光(CL)、U-Pb年龄和U、Th等微量元素的测定分析。研究结果表明:锆石拉曼光谱1008cm^(-1)峰的半高宽普遍小于20cm^(-1),指示锆石结晶程度较好到中等程度的蜕晶化;早期继承锆... 对大别山高压-超高压片麻岩的锆石进行了激光拉曼探针、阴极发光(CL)、U-Pb年龄和U、Th等微量元素的测定分析。研究结果表明:锆石拉曼光谱1008cm^(-1)峰的半高宽普遍小于20cm^(-1),指示锆石结晶程度较好到中等程度的蜕晶化;早期继承锆石在三叠纪高压-超高压变质作用中经历了退火和重结晶作用,所受的放射性通量是从200Ma的早侏罗纪开始积累的,表明高压-超高压岩石在这一时间已出露地表;北大别白垩纪岩浆热事件对高压-超高压岩石的影响很小;大多数锆石数据都落在天然锆石的放射性破坏趋势(RDT)中,表明锆石在高压、超高压过程中基本发生了完全的重结晶。 展开更多
关键词 大别山 高压片麻岩 锆石拉曼光谱 激光拉曼探针 光谱学研究 DABIE Mountains HP-UHP 超高压岩石 metamorphic rocks radiation damage 超高压变质作用 trace elements 重结晶作用 放射性 during significant North DABIE Laser Raman the earth 阴极发光
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The Basic Indexes and Practices of Regional Ecological Agricultural Construction in Dabie Mountains——A Case Study of Huanggang,Hubei
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作者 鲍宏礼 鲁丽荣 《Agricultural Science & Technology》 CAS 2017年第4期740-743,共4页
Taking Huanggang city as an example, the requirements of basic indexes for the regional ecological agricultural construction in Dabie Mountains were ana- lyzed and the measures that must be taken in implementing the i... Taking Huanggang city as an example, the requirements of basic indexes for the regional ecological agricultural construction in Dabie Mountains were ana- lyzed and the measures that must be taken in implementing the in the Dabie Mountains were proposed. 展开更多
关键词 Dabie Mountains Huanggang Basic indexes of ecological agricultural construction
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即将发作的Dabi病毒的诊治与免疫
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作者 郭钧锋 范荣 《电子与电脑》 1994年第4期18-20,共3页
计算机病毒在国内的传播和发展已有近十年的历史了。从引导型、文件型、混合型,到一年前出现的DOS内核型病毒DIR—2,呈现出一种由简单到复杂,并逐渐深入DOS内核的发展趋势,其隐蔽性也逐渐加强,发现和防治的难度不断加大。 我们最近发现... 计算机病毒在国内的传播和发展已有近十年的历史了。从引导型、文件型、混合型,到一年前出现的DOS内核型病毒DIR—2,呈现出一种由简单到复杂,并逐渐深入DOS内核的发展趋势,其隐蔽性也逐渐加强,发现和防治的难度不断加大。 我们最近发现了一种隐蔽性很强的新病毒。由于它传染了一个具有自身防护能力的解病毒程序,致使该程序无法运行,从而偶然发现了该病毒的存在。 展开更多
关键词 计算机病毒 诊治 DABI病毒
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DABI(1465)病毒的原理及诊治
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作者 郭书军 《电脑技术——Hello-IT》 1996年第9期23-23,共1页
关键词 计算机病毒 诊治 DABI病毒
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Role of the Nocturnal Low-level Jet in the Formation of the Morning Precipitation Peak over the Dabie Mountains 被引量:16
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作者 Peiling FU Kefeng ZHU +2 位作者 Kun ZHAO Bowen ZHOU Ming XUE 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2019年第1期15-28,共14页
The diurnal variation of precipitation over the Dabie Mountains(DBM) in eastern China during the 2013 mei-yu season is investigated with forecasts of a regional convection-permitting model. Simulated precipitation is ... The diurnal variation of precipitation over the Dabie Mountains(DBM) in eastern China during the 2013 mei-yu season is investigated with forecasts of a regional convection-permitting model. Simulated precipitation is verified against surface rain-gauge observations. The observed morning precipitation peak on the windward(relative to the prevailing synoptic-scale wind) side of the DBM is reproduced with good spatial and temporal accuracy. The interaction between the DBM and a nocturnal boundary layer low-level jet(BLJ) due to the inertial oscillation mechanism is shown to be responsible for this precipitation peak. The BLJ is aligned with the lower-level southwesterly synoptic-scale flow that carries abundant moisture.The BLJ core is established at around 0200 LST upwind of the mountains. It moves towards the DBM and reaches maximum intensity at about 70 km ahead of the mountains. When the BLJ impinges upon the windward side of the DBM in the early morning, mechanical lifting of moist air leads to condensation and subsequent precipitation. 展开更多
关键词 nocturnal boundary layer low-level jet diurnal variation PRECIPITATION Dabie Mountains meiyu season
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Petrology, Metamorphic Process and Genesis of The Dabie--Sulu Eclogite Belt, Eastern--Central China 被引量:17
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作者 Zhang Zeming You Zhendong Han Yujing and Sang Longkang Department of Earth Sciences, China University of Geosciences, Wuhan, Hubei 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 1996年第2期134-156,共23页
The Qinling-Dabie-Sulu high-pressure and ultra-high pressure metamorphic belt wasformed by subduction and collision between the North China and Yangtze plates. The study ofthe eclogite belt is very important in unders... The Qinling-Dabie-Sulu high-pressure and ultra-high pressure metamorphic belt wasformed by subduction and collision between the North China and Yangtze plates. The study ofthe eclogite belt is very important in understanding the evolution of the Qinling Dabie orogen. Inthe present paper the geology, petrology, minerology and chronology of the eclogites in the Dabieand Sulu areas are described. The principal conclusions of this work are as follows: (1) Based up-on the field occurrence and the P-T conditions of the eclogites, two types of eclogite can be dis-tinguished: Type 1—the low-temperature and high-pressure eclogite in the mid-late Proterozoicmetamorphic series, and Type 2—the ultra-high pressure eclogite in the late Archaean to earlyProterozoic metamorphic complex. In the Dabie area, the ultra-high-pressure eclogite,high-pressure eclogite and epidote-blueschist units are nearly parallel to each other and stretchintermittently from north to south. (2) The P-T conditions of the high-pressure eclogites and ul-tra-high pressure eclogites have been estimated. The former are formed at 450-550℃ and1.4-1.6 GPa; while the latter at 650-870℃ and >2.7-2.9 GPa in the Dabie area and at820-1000℃ and >2.8-3.1 GPa in the Sulu area. The metamorphic temperatures of the eclogitesincrease progressively from west to east. (3) The ultra-high pressure eclogites were subjected to 5stages of metamorphism: pre-eclogite epidote amphibolite facies, peak coesite eclogite facies,post-eclogite amphibolite facies, epidote-blueschist facies or epidote amphibolite facies andgreenschist facies. The general features of the PTt path of the ultra-high pressure eclogite are:clockwise pattern, progressive metamorphism being a process of slow increasing temperature andrapid increasing pressure, and the retrogressive section with nearly isothermal decompression atthe early stage, isobaric cooling at the middle stage and nearly isothermal decompression at thelate stage. (4) At least two stages of high-pressure metamorphism occurred in the orogenic belt:the high-pressure eclogite and ultra-high pressure eclogite were formed by the subduction of theoceanic crust northward beneath the North China plate or the Dabie block during theCaledonian; while the epidote-blueschist belt came into being by subdution and collision be-tween the two continental plates during the Indosinian. (5) Due to the continuous sequentialsubduction of the cold plate, the ultra high-presssure metamorphic rocks were uplifted to thecrust by the underplating processes. They can be preserved just because of the 'frozen effect' re-sulting from the continuous subduction of the cold plate. (6) The carbonates, such as magnesite,breunnerite, aragonite and dolomite, and the H_2O-bearing minerals, such as phengite, epidoteand zoisite, were stable during the high-pressure and/or ultra-high pressure metamorphism. 展开更多
关键词 PETROLOGY mineral chemistry chronology PTt—path Dabie—Sulu eclogite belt east—central China
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Location of Triassic Tectonic Suture Between Collided Sino-Korean and Yangtze Cratons in Dabie-Sulu Region, China 被引量:11
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作者 Suo Shutian Zhong Zengqiu You Zhendong(Faculty of Earth Sciences, China University of Geosciences, Wuhan 430074) 《Journal of Earth Science》 SCIE CAS CSCD 1999年第4期281-286,共6页
The regional extent and spatial distribution of ultrahigh pressure metamorphic(UHPM) and high pressure metamorphic (HPM) rocks, and the geometrical relationships of various petrotectonic units in the Dabie-Sulu region... The regional extent and spatial distribution of ultrahigh pressure metamorphic(UHPM) and high pressure metamorphic (HPM) rocks, and the geometrical relationships of various petrotectonic units in the Dabie-Sulu region indicate that the Triassic collisional suture line between the Sino-Korean and Yangtze cratons is situated at the northern margin of the Dabie massif, that is,along the Balifan-Mozitan-Xiaotian fault in the Dabie region, and possibly is linked to the Wulian-Yantai fault in the Sulu region to tbe east. The suture line has been strongly modified duriug and subsequent to UHPM aud HPM events. 展开更多
关键词 UHPM and HPM belts suture line Dabie massif Dabie-Sulu region
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^(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 被引量:11
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作者 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 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 1999年第1期78-83,127-128,共8页
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 andoccurren... 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 ^(207)Pb/^(206)Pb 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. 展开更多
关键词 Dabie Mountains granulite facies ARCHAEAN multistage evolution ZIRCON 207~Pb/206~Pb
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Zircon Geochronological Evidence for Participation of the North China Craton in the Protolith of Migmatite of the North Dabie Terrane 被引量:10
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作者 Haijin Xu Junfeng Zhang 《Journal of Earth Science》 SCIE CAS CSCD 2018年第1期30-42,共13页
The plate affiliation of the North Dabie terrane (NDT) has been controversial. To address this fundamental question, an integrated study of internal structure, in-situ U-Pb dating and trace element analysis in zirco... The plate affiliation of the North Dabie terrane (NDT) has been controversial. To address this fundamental question, an integrated study of internal structure, in-situ U-Pb dating and trace element analysis in zircons and field investigation for migmatite in the NDT was carried out, which reveals par- ticipation of crustal rocks of the North China Craton (NCC) in the protolith in addition to the more common crustal rocks of the Yangtze Craton (YC). The evidence of an NCC affinity for protolith of migmatite in the NDT is the -2.5 Ga (2 486±14 and 2 406±26 Ma) magamtic age and -1.8 Ga (1 717±79 Ma) metamorphic age in the relict zircon domains because these two age groups are characteristic for the evolution of the NCC. The evidence of a YC affinity for protolith of migmatite in the NDT is the more common 0.7-0.8 Ga (e.g., 787±12 Ma) magamtic zircon age. Mid-Neoproterozoic magmatic age (0.7-0.8 Ga) is a symbol of YC basement rocks. In view of the widely exposed YC crustal components in the NDT, we suggest that the protolith of the NDT is mainly crustal rocks from the YC with minor crustal components from the NCC. The zircon rim domains and new growth grains from all the migmatite sam- ples are characterized by anatectic zircons and have a widely concordant ages ranging from 112.2±2.8 to 159.6±4.3 Ma with several peak values, suggesting a long lasting multistage anatexis. In conclusion, the NDT has a mixed protolith origin of both the YC and the NCC crustal rocks were strongly remoulded by anatexis during orogenic collapse. 展开更多
关键词 North Dabie terrane MIGMATITE zircon U-Pb age PROTOLITH tectonic affinity.
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Geochemical Characteristics and Genesis of the Granitic Gneisses from the Southeastern Dabie Mountains 被引量:9
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作者 薛怀明 董树文 刘晓春 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2001年第2期175-183,共9页
The granitic gneisses from the ultrahigh-pressure (UHP) metamorphic terrain of the southeastern Dabie Mountains encompass two types: monzonitic granitic gneiss and alkali-feldspar granitic gneiss, which are characteri... The granitic gneisses from the ultrahigh-pressure (UHP) metamorphic terrain of the southeastern Dabie Mountains encompass two types: monzonitic granitic gneiss and alkali-feldspar granitic gneiss, which are characterized by rich alkalis, poor CaO, high FeO/MgO, particularly high Ba, Rb, Th, Ta, REE (except Eu), Ga, Nb and Zn, and low Sr, Eu, Cr, Co and Ni. The gneisses, particularly the alkali-feldspar granitic gneiss, have typical chemical characteristics of A-type granites. They resulted from partial melting of crustal materials existing in the rift zone along the northern margin of the South China block during the Neoproterozoic. These gneisses might not have undergone UHP metamorphism during the late Triassic, but were involved into UHP rocks by the tectonic mixing process and kept the exhumation message of the UHP rocks from the middle and upper crust. 展开更多
关键词 granitic gneiss A-type granite UHP complex PROTEROZOIC Dabie Mountains
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Convective Initiation by Topographically Induced Convergence Forcing over the Dabie Mountains on 24 June 2010 被引量:9
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作者 Qiwei WANG Ming XUE Zhemin TAN 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2016年第10期1120-1136,共17页
The initiation of convective cells in the late morning of 24 June 2010 along the eastward extending ridge of the Dabie Mountains in the Anhui region, China, is studied through numerical simulations that include local ... The initiation of convective cells in the late morning of 24 June 2010 along the eastward extending ridge of the Dabie Mountains in the Anhui region, China, is studied through numerical simulations that include local data assimilation. A primary convergence line is found over the ridge of the Dabie Mountains, and along the ridge line several locally enhanced convergence centers preferentially initiate convection. Three processes responsible for creating the overall convergence pattern are identified. First, thermally-driven upslope winds induce convergence zones over the main mountain peaks along the ridge, which are shifted slightly downwind in location by the moderate low-level easterly flow found on the north side of a Mei-yu front. Second, flows around the main mountain peaks along the ridge create further convergence on the lee side of the peaks. Third, upslope winds develop along the roughly north-south oriented valleys on both sides of the ridge due to thermal and dynamic channeling effects, and create additional convergence between the peaks along the ridge. The superposition of the above convergence features creates the primary convergence line along the ridge line of the Dabie Mountains. Locally enhanced convergence centers on the primary line cause the initiation of the first convection cells along the ridge. These conclusions are supported by two sensitivity experiments in which the environmental wind (dynamic forcing) or radiative and land surface thermal forcing are removed, respectively. Overall, the thermal forcing effects are stronger than dynamic forcing given the relatively weak environmental flow. 展开更多
关键词 Dabie Mountains convective initiation low-level convergence line thermal forcing dynamic forcing
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Thrusting and Exhumation Processes of a Bounding Mountain Belt: Constraints from Sediment Provenance Analysis of the Hefei Basin 被引量:12
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作者 刘少峰 刘文灿 +2 位作者 戴少武 黄思骥 陆五云 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2001年第2期144-150,共7页
Lithic (or gravel) composition analyses of the Jurassic Sanjianpu Formation and Fenghuangtai Formation in the Hefei basin show that the sediment provenance consists mainly of four kinds of rock units: the basement met... Lithic (or gravel) composition analyses of the Jurassic Sanjianpu Formation and Fenghuangtai Formation in the Hefei basin show that the sediment provenance consists mainly of four kinds of rock units: the basement metamorphic complex, granitic rocks, medium- and low-grade metamorphic rocks, and sandy and muddy sedimentary rocks, which are distributed along the bounding thrust belt. The whole stratigraphic section can be divided into 2 lithic sequences and 7 subsequences. The regular distribution and changes of lithic fragments and gravels in lithic (or gravel) sequences reflect that the bounding thrust belt of basin has undergone 2 thrusting cycles and 7 thrusting events. Lithic (or gravel) composition analyses of the basin fully reveal that the northern Dabie basement metamorphic complex was exhumed on the earth's surface in the Middle and Late Jurassic, and extensive intermediate and acid intrusive rocks were developed in the southern North Huaiyang or northern Dabie Mountains during the basin's syndepositional stage. 展开更多
关键词 northern Dabie Mountains Hefei basin sediment provenance thrusting and exhumation
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Thermal Evolution of the Tanlu Fault Zone on the Eastern Margin of the Dabie Mountains and Its Tectonic Implications 被引量:14
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作者 ZHUGuang HOUMinjin +2 位作者 WANGYongsheng LIUGuosheng NIUManlan 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2004年第4期940-953,共14页
Five samples of muscovite from mylonites of the earlier Tanlu ductile shear zone on the eastern margin of the Dabie Mountains yield 40Ar/39Ar ages ranging from 178 Ma to 196 Ma. Three of them have reliable plateau age... Five samples of muscovite from mylonites of the earlier Tanlu ductile shear zone on the eastern margin of the Dabie Mountains yield 40Ar/39Ar ages ranging from 178 Ma to 196 Ma. Three of them have reliable plateau ages of 188.7±0.7 Ma, 189.7±0.6 Ma and 192.5±0.7 Ma respectively, which indicates a syn-orogenic, sinistral strike-slip thermal event. This displacement movement derived from the continent-continent collision of the North and South China blocks took place in the Early Jurassic and after uplifting of high-pressure to ultrahigh-pressure slabs to the mid-crust. It is suggested that during the collision the Tanlu fault zone was an intracontinental transform fault caused by differential subduction speeds. The 40Ar/39Ar ages of mylonite whole-rock and muscovite from the later Tanlu ductile shear zone suggest another sinistral strike-slip cooling event at 128 Ma. During this strike-slip faulting, large-scale intrusion and doming uplift occurred in the eastern part of the Dabie orogenic belt. Data of K-feldspar 40Ar/39Ar MDD and apatite fission-track analysis from metamorphic rocks indicate two high-speed cooling events experienced by the Tanlu fault zone, which took place at 90 Ma and 45-58 Ma respectively. They correspond respectively to two phases of extensional activities in the Late Cretaceous and Eogene as well as development of the Qianshan fault-controlled basin to the east of the Tanlu fault zone. The cooling times recorded by K-feldspar and apatite show that the uplifting in the Dabie orogenic belt occured earlier than that on the eastern margin occupied by the Tanlu fault zone. The above phenomena suggest that the uplifting of the Dabie orogenic belt during the Late Cretaceous to Eogene was not controlled by the Tanlu normal faulting, but as a result of the lithospheric delamination. 展开更多
关键词 Tanlu fault zone Dabie orogenic belt 40Ar/39Ar age fission-track age thermal event
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A New Species of the Genus Rhacophorus (Anura: Rhacophoridae) from Dabie Mountains in East China 被引量:8
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作者 Tao PAN Yanan ZHANG +9 位作者 Hui WANG Jun WU Xing KANG Lifu QIAN Kai LI Yu ZHANG Jinyun CHEN Dingqi RAO Jianping JIANG Baowei ZHANG 《Asian Herpetological Research》 SCIE CSCD 2017年第1期1-13,共13页
A new species of rhacophorid of the genus Rhacophorus is described from the Dabie Mountains of west Anhui, east China. The new species, Rhacophorus zhoukaiyae sp. nov. is distinguished from its congeners by a combinat... A new species of rhacophorid of the genus Rhacophorus is described from the Dabie Mountains of west Anhui, east China. The new species, Rhacophorus zhoukaiyae sp. nov. is distinguished from its congeners by a combination of the following characters: 1) the ventral surface and front-and-rear of the femur is paler yellowish and decorated with irregular grayish blotching, and without obvious spots on the dorsum of the hand and foot webbing; 2) the outer metatarsal tubercle is small; 3) outer fingers are half-webbed and outer toes two third webbed; 4) the skin on the dorsum is smooth and without compressed warts; 5) the throat, chest and belly are pure paler yellowish; 6) the dorsal part of the fingers and toes are grayish-white; 7) the iris is golden-yellow. In addition, the phylogenetic tree showed that all the individuals of R. zhoukaiyae sp. nov. clustered into one distinct clade which suggested the validity of this species. This results could also be used to the support of species delimitation. Currently, this species is known only from mid-elevation montane evergreen forest in the Dabie Mountains of west Anhui, China. 展开更多
关键词 Rhacophorus Rhacophorus zhoukaiyae sp. nov. PHYLOGENY Rhacophoridae Dabie Mountains
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