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晋代音注中的鱼部 被引量:3
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作者 简启贤 《古汉语研究》 CSSCI 北大核心 2003年第1期20-24,共5页
用《字林》、郭璞、徐邈的音注材料考察晋代鱼部的情况,用押韵材料作对比,发现古侯部中的虞韵字已经和古鱼部中的虞韵字合并,鱼、虞、模三韵分划清楚,模韵并不更接近虞韵,中原方言只是个别鱼韵字读同虞韵(或相反),齐鲁方言和中原方言的... 用《字林》、郭璞、徐邈的音注材料考察晋代鱼部的情况,用押韵材料作对比,发现古侯部中的虞韵字已经和古鱼部中的虞韵字合并,鱼、虞、模三韵分划清楚,模韵并不更接近虞韵,中原方言只是个别鱼韵字读同虞韵(或相反),齐鲁方言和中原方言的鱼韵和虞韵韵腹相同而韵头不同,江东方言的鱼韵和虞韵韵腹相异而且韵头也可能不同。 展开更多
关键词 音注 鱼部 中原方言 齐鲁方言 江东方言 汉语 语音 侯部 屋部 虞韵字 模韵 韵膜
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每月行情
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《江西农业科技》 2005年第3期43-44,共2页
关键词 凌家塘 岳各庄 八里桥 北园 石门 开拓巷道 江鲁
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Grain-size Characteristics of Sediments Formed Since 8600 yr B.P. in Middle Reaches of Yarlung Zangbo River in Tibet and Their Paleoenvironmental Significance 被引量:10
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作者 ZHENG Yinghua WU Yongqiu +3 位作者 LI Sen TAN Lihua GOU Shiwei ZHANG Hongyan 《Chinese Geographical Science》 SCIE CSCD 2009年第2期113-119,共7页
Widespread aeolian sediments have been found in the middle reaches of the Yarlung Zangbo River, China, The grain-size characteristics of sediments from Cha'er Section in the area were analyzed. The results show that ... Widespread aeolian sediments have been found in the middle reaches of the Yarlung Zangbo River, China, The grain-size characteristics of sediments from Cha'er Section in the area were analyzed. The results show that the section include one stratum of paleo-mobile dunes, four strata of paleo-semi-fixed dunes, two strata of paleo-fixed dunes, one stratum of sandy immature soils. The paleo-mobile and paleo-semi-fixed dune sand in this section are similar to modem aeolian sand in either grain-size composition or Mz and c distribution. Compared the above types of dunes each other, the content of sand substance decreases, while the content of silt and clay increases for paleo-fixed dunes and sandy immature soils. Combined with age data for each stratum, the analysis shows that these strata are the products of climate changes and the evolution of aeolian landforms. The evolutionary sequence of the paleoclimate and of aeolian activities in the valley since 8600 yr B.P. reveals four stages: 8600-5700 yr B.P., when the paleoclimate was cold and dry, with strong winds, thereby activating dunes; 5700-3600 yr B.P., when it was warm and wet, with weak winds, causing dunes to undergo soil-forming processes; 3600-1900 yr B.P., when climate shifted from cold-dry with strong winds to warm-wet with weak winds, and activated dunes were fixed again; and 1900 yr B.P. -present, when the climate became fine, with weak winds, fixing dunes again. 展开更多
关键词 HOLOCENE TIBET Yarlung Zangbo River grain size characteristics Cha'er Section
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Debris-flow of Zelongnong Ravine in Tibet 被引量:4
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作者 ZHANG Jinshan SHEN Xingju 《Journal of Mountain Science》 SCIE CSCD 2011年第4期535-543,共9页
Zelongnong Ravine,a branch ravine of Brahmaputra,is an old large glacier debris-flow ravine.Debris-flows with medium and/or small scales occur almost every year;multiple super debris-flows have also broken out in hist... Zelongnong Ravine,a branch ravine of Brahmaputra,is an old large glacier debris-flow ravine.Debris-flows with medium and/or small scales occur almost every year;multiple super debris-flows have also broken out in history,and have caused destructive disaster to local residents at the mouth of ravine and blocked Brahmaputra.The huge altitude difference and the steep slope of the Zelongnong Ravine provide predominant energy conditions for the debris-flow.The drainage basin is located in the fast uplifted area,where the complicated geologic structure,the cracked rock,and the frequent earthquake make the rocks experience strong weathering,thus plenty of granular materials are available for the formation of debris-flows.Although this region is located in the rain shadow area,the precipitation is concentrated and most is with high intensity.Also,the strong glacier activity provides water source for debris-flow.According to literature reviews,most debris-flows in the ravine are induced by rainstorms,and their scales are relatively small.However,when the melted water is overlaid,the large scale debris-flows may occur.Parametric calculation such as the flow velocity and the runoff is conducted according to the monitoring data.The result shows that large debris-flows can be aroused when the rainstorm and the melted water are combined well,but the possibility of blocking off Brahmaputra is rare.The occurrence of the super debris-flows is closely related to the intense glacier activity(e.g.,glaciersurge).They often result in destructive disasters and are hard to be prevented and cured by engineering measures,due to the oversized scales.The hazard mitigation measures such as monitoring and prediction are proposed. 展开更多
关键词 TIBET The Brahmaputra The Mt Namjagbarwa Zelongnong Ravine DEBRIS-FLOW
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The Relationship between Normalized Difference Vegetation Index(NDVI) and Climate Factors in the Semiarid Region:A Case Study in Yalu Tsangpo River Basin of Qinghai-Tibet Plateau 被引量:11
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作者 GUO Bing ZHOU Yi +1 位作者 WANG Shi-xin TAO He-ping 《Journal of Mountain Science》 SCIE CSCD 2014年第4期926-940,共15页
The Yalu Tsangpo River basin is a typical semi-arid and cold region in the Qinghai-Tibet Plateau, where significant climate change has been detected in the past decades. The objective of this paper is to demonstrate h... The Yalu Tsangpo River basin is a typical semi-arid and cold region in the Qinghai-Tibet Plateau, where significant climate change has been detected in the past decades. The objective of this paper is to demonstrate how the regional vegetation, especially the typical plant types, responds to the climate changes. In this study, the model of gravity center has been firstly introduced to analyze the spatial-temporal relationship between NDVI and climate factors considering the time-lag effect. The results show that the vegetation grown has been positively influenced by the rainfall and precipitation both in moving tracks of gravity center and time-lag effect especially for the growing season during the past thirteen years. The herbs and shrubs are inclined to be influenced by the change of rainfall and temperature, which is indicated by larger positive correlation coefficients at the 0.05 confidence level and shorter lagging time. For the soil moisture, the significantly negative relationship of NDV-PDI indicates that the growth and productivity of the vegetation are closely related to the short-term soil water, with the correlation coefficients reaching the maximum value of o.81 at Lag 0-1. Among the typicalvegetation types of plateau, the shrubs of low mountain, steppe and meadow are more sensitive to the change of soil moisture with coefficients of -0.95, -0.93, -0.92, respectively. These findings reveal that the spatial and temporal heterogeneity between NDVI and climatic factors are of great ecological significance and practical value for the protection of eco-environment in Qinghai-Tibet Plateau. 展开更多
关键词 Climate change Gravity center Correlation coefficients Vegetation productivity Time-lag effect
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Analysis of Longitudinal Profiles along the Eastern Margin of the Qinghai-Tibetan Plateau 被引量:3
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作者 Simon J. Aiken Gary J. Brierley 《Journal of Mountain Science》 SCIE CSCD 2013年第4期643-657,共15页
Resulting from the collision of the Eurasian and Indian plates, the Qinghai-Tibetan Plateau is commonly known as the 'roof of the world'. Collectively the Yarlung Tsangpo, Nu, Laneang, Yangtze, Yalong, and Yellow Ri... Resulting from the collision of the Eurasian and Indian plates, the Qinghai-Tibetan Plateau is commonly known as the 'roof of the world'. Collectively the Yarlung Tsangpo, Nu, Laneang, Yangtze, Yalong, and Yellow River basins drain the eastern margin of the plateau. In this paper, we utilize Shuttle Radar Topography Mission elevation data to examine morphometric and relief attributes of these basins to reveal insights rates of incision. A robust into tectonic activity and technique using Maflab is proposed to alleviate errors associated with SRTM data in the derivation of river longitudinal profiles. Convex longitudinal profiles are interpreted to be a product of uplift rates that exceed rates of channel incision along the entire margin of the Qinghai- Tibetan Plateau. Highest relief towards the south reflects extensive fluvial incision. High relief is also prominent along major active faults. Erosion patterns are related to distance from knickpoints. Highest rates of erosion and incision are evident towards the south, with decreasing values towards the north, suggesting a link between tectonic activity and erosion. 展开更多
关键词 Longitudinal profile EROSION RELIEF TECTONICS Qinghai-Tibetan Plateau
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Influence of Eco-friendly Manures on Leaf Biomass Production of a Traditional Medicinal Plant Adhatoda vasica Nees under Upper Brahmaputra Valley Agroclimatic Zone
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作者 Sristisri Upadhyay Lakhi Ram Saikia 《Journal of Agricultural Science and Technology(A)》 2012年第1期115-119,共5页
Effect of different organic manures on production of leaf biomass of a potential medicinal plant Adhatoda vasica Nees. was studied at Dibrugarh University under Upper Brahmaputra Valley Agroclimatic Zone of India duri... Effect of different organic manures on production of leaf biomass of a potential medicinal plant Adhatoda vasica Nees. was studied at Dibrugarh University under Upper Brahmaputra Valley Agroclimatic Zone of India during 2008-2010. The aim was to know about the agronomic requirements of the wild medicinal plant for its organic cultivation. The plant reproduces by vegetative means through stem cutting. The nursery plants were prepared from the terminal soft-wood cuttings. The experiments were laid down in RBD with 3 m ×6 m block sizes. Cowdung, compost and vermicompost were used as organic manure. Manures were applied at three levels eg. cowdung at 12.0, 19.5 and 27.0 t ha-1 compost at 7.5, 15.0 and 27.7 t ha-1 and vermicompost at 2.5, 3.0 and 3.75 t ha-1. Eighty percent of every dose was applied one week ahead of plantation and the rest was applied after two months of plantation. Irrigation was not necessary as usual rainfall occurred during the period. Hand weeding was done first time after two months of plantation and again just before application of the second part of the manure. Mature leaves were first harvested by picking them in the first week of October to avoid loss due to leaf fall and finally all the leaves were harvested by teaming the branches in second week of November. In the next year, the mature leaves of the newly sprouted branches on the teamed plants were harvested in May and the final harvest was done by teaming the branches again in October. The total leaf biomass was expressed in t ha-1 (dry wt.). The total nitrogen in the manure was determined by kjeldahl method, phosphorus by spectrophotometric method and potassium by flame photometric method, pH in 1:5 water suspension and organic matter by Walkley and Black's titration method. Maximum leaf biomass (2.74 t ha1) and economic benefit (Rs. 30,941 ha-1) were obtained in cowdung at 27.0 t ha-1 followed by cowdung at 19.5 t ha-1(2.50 t hal and Rs. 26,955 ha-1), compost at 22.7 t ha-1 (2.35 t ha-1 and Rs. 22,132 hal). Organic cultivation ofA. vasica, using locally available and cheap organic manures like cowdung and compost is highly encouraging. The technique is eco-friendly and its value will be many times more if it is calculated in terms of environmental health. The technique is therefore, recommended for sustainable management of the wild and important medicinal plant of this Agroclimatic Zone. Vermicompost is not advisable because of its higher input cost than the others. 展开更多
关键词 Adhatoda vasica traditional medicinal plant organic manures
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An Analysis of Wetland Degradation in the Dimoria Region of Assam, India
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作者 Dharma Ram Deka Pradip Sharma 《Journal of Life Sciences》 2013年第7期781-786,共6页
The wetlands of the Brahmaputra valley include lake-like natural water bodies locally known as 'beel', and degenerated lakes, which are often called as swamps. The role of such wetlands in socio-economic condition o... The wetlands of the Brahmaputra valley include lake-like natural water bodies locally known as 'beel', and degenerated lakes, which are often called as swamps. The role of such wetlands in socio-economic condition of the people is significant from various angles. Apart from the wetlands act as the ideal habitats for feeding, nesting and breeding of a large variety of fishes, birds and other aquatic animals, these features maintain the environmental quality of the region. Present study has been conducted primarily in eight selected beels in the Dimoria region, which is located almost at the south-central part of the Brahmaputra valley. The water and soil samples from these wetlands had been collected using random sampling technique and analyzed to know about the nature of degradation of the wetlands. Once highly productive wetland waters now show very low DO, high BOD and COD, indicating dwindling productivity of fish and other aquatic resources. Higher value of pH in soils of most of the wetlands found probably due to the impact of industrial effluents and urban sewage and use of chemical fertilizers in the paddy field of the fringe areas, which again create toxic environment and ultimately reduces fish productivity. 展开更多
关键词 Brahmaputra valley beel dimoria environmental quality fish productivity.
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Multivariant statistical analysis for diagenetic information of chert from southern Tibet,China
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作者 HE Junguo ZHOU Yongzhang +1 位作者 FU Wei LI Hongzhong 《Global Geology》 2011年第2期94-101,共8页
There are large scale chert formations of different ages exposed widely in southern Tibet, along Yarlung-Zangbo suture zone. The typical chert specimens were sampled from Pengcuolin, Xialu and Zongzhuo profiles. Multi... There are large scale chert formations of different ages exposed widely in southern Tibet, along Yarlung-Zangbo suture zone. The typical chert specimens were sampled from Pengcuolin, Xialu and Zongzhuo profiles. Multivariate statistical analysis is applied for effectively extracting the geochemical information of the chert, and the raw data are processed by R-factor analysis. The first, second and third factors representing terrigenous, authigenic and hydrothermal constituents are extracted from the analysis results. From Pengcuolin, Xialu to Zongzhuo chert profiles, the variance ratios of continental and authigenetic factors become higher ( 51. 1% →62.9 % →91.6 % ), while hydrothermal factor rapidly decrease ( 40. 9 % →32.2 % →0 ). This tend- eney also present in the analysis for traee elements, indicating that Pengeuolin chert is hydrothermal origin, The Zongzhuo chert belong to normal sedimentation and the Xialu chert exhibit normal deposition interacted with hydrothermal sedimentation. The facts provide significant implications for understanding the diagenetic and palaeomineralization information of southern Tibet. 展开更多
关键词 factor analysis chert diagenetic information southern Tibet
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脚踩大地 一心逐"高"
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作者 任斐斐 丁变红 《当代兵团》 2024年第11期48-48,共1页
5月20日一大早,六师农业科学研究所副研究员陈江鲁就到奇台农场二十五连小麦地里察看冬小麦长势."从事小麦、玉米高效栽培技术研究工作,只有到现场去、到地里去,才能看到作物每天发生的变化,才能优中选优,拿到翔实的试验数据."... 5月20日一大早,六师农业科学研究所副研究员陈江鲁就到奇台农场二十五连小麦地里察看冬小麦长势."从事小麦、玉米高效栽培技术研究工作,只有到现场去、到地里去,才能看到作物每天发生的变化,才能优中选优,拿到翔实的试验数据."陈江鲁一边说着,一边抚摸着麦苗,仔细察看叶片长势. 展开更多
关键词 农业科学研究所 高效栽培技术 奇台农场 冬小麦 试验数据 麦苗 江鲁 长势
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进口一般商品配额管理简介
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作者 水才 《中国海关》 北大核心 1994年第11期36-36,共1页
根据计经贸[1994]421号文件规定,由国家计划委员会负责对25种一般商品进口实行配额管理,各进口单位凭国家计委或由国家计委授权的配额管理机关审核签发的“一般商品进口配额证明”,到外经贸部或由外经贸部授权签发进口许可证的机关,申... 根据计经贸[1994]421号文件规定,由国家计划委员会负责对25种一般商品进口实行配额管理,各进口单位凭国家计委或由国家计委授权的配额管理机关审核签发的“一般商品进口配额证明”,到外经贸部或由外经贸部授权签发进口许可证的机关,申领进口许可证。未经国家计委授权的国务院其他部门,其所属企业需进口配额商品的,由外经贸部按照国家计委下达的配额,办理“一般商品进口配额证明”并签发进口许可证。海关一律凭授权签发许可证机关签发的进口许可证验放。 展开更多
关键词 进口许可证 配额管理 国家计委 商品进口 管理简介 彩色感光材料 汽车轮胎 聚酯切片 江鲁
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Community Structure and Diversity Distribution Pattern of Sandy Plants in the Middle and Upper Reaches of the Yarlung Zangbo River 被引量:6
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作者 LI Chao XU Wenli +1 位作者 LI Qingkang WANG Jingsheng 《Journal of Resources and Ecology》 CSCD 2021年第1期11-21,共11页
The Yarlung Zangbo River Basin is an important populated area in Tibet, and its plant community structure and diversity pattern have attracted the attention of many scholars. In this paper, the distribution pattern of... The Yarlung Zangbo River Basin is an important populated area in Tibet, and its plant community structure and diversity pattern have attracted the attention of many scholars. In this paper, the distribution pattern of plant diversity and the environmental factors impacting it in the middle and upper reaches of the Yarlung Zangbo River are revealed and discussed through sample surveys and climate and habitat data. The results show that the plant communities in the study area can be divided into seven types according to the dominant species: Artemisia minor + Stipa purpurea, Artemisia wellbyi + Festuca ovina, Potentilla fruticosa + Orinus thoroldii, Trikeraia hookeri + Artemisia frigida, Kobresia pygmaea, Sophora moorcroftiana + Artemisia hedinii, and Sophora moorcroftiana + Pennisetum centrasiaticum. Plant diversity decreases with decreasing longitude, increasing latitude, and increasing altitude;and the diversity distribution pattern in the study area has distinct zonal characteristics. Water and heat are the main factors which affect the distribution of vegetation types. The explanation rates of water and heat for the plant diversity distribution pattern were 19.3% and 5.7%, respectively, while the spatial variation explained by these two factors together was 60.8%. Therefore, the coupling effect is obvious. 展开更多
关键词 Yarlung Zangbo River community structure DIVERSITY pattern
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Quantitative Classification and Ordination of Plant Communities in the Upper and Middle Reaches of the Yarlung Zangbo River Basin 被引量:9
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作者 WANG Tong WANG Jingsheng +3 位作者 DING Yuke LIU Wenjing BAO Xiaoting LI Chao 《Journal of Resources and Ecology》 CSCD 2019年第4期389-396,共8页
Based on vegetation survey data and environmental data of the Yarlung Zangbo River Basin, we conducted a quantitative ecological analysis of the vegetation community composition and the relationship between species an... Based on vegetation survey data and environmental data of the Yarlung Zangbo River Basin, we conducted a quantitative ecological analysis of the vegetation community composition and the relationship between species and the environment in the study area. The results showed that 44 sampling sites and 68 plant species in the study area can be classified into seven subtypes: Artemisia minor + Stipa purpurea;Artemisia demissa + Stipa purpurea + Artemisia wellbyi;Kobresia pygmaea;Trikeraia hookeri;Sophora moorcroftiana + Cotoneaster multiflorus + Pennisetum centrasiaticum;Artemisia frigida;Potentilla fruticosa + Orinus thoroldii. Detrended correspondence analysis(DCA) indicated that both longitude and altitude play important roles in site and species distribution patterns. In addition, canonical correspondence analysis(CCA) revealed that in the upper and middle reaches of the Yarlung Zangbo River Basin, changes in temperature and precipitation caused by longitude are the main factors controlling the formation and transition of vegetation community types. Moreover, natural vegetation could be divided into three types: desert steppe community(source area), alpine steppe community(middle reaches region), and shrub community(confluence of Yarlung Zangbo River and Nyangqu River). 展开更多
关键词 upper and middle reaches of the Yarlung Zangbo River plant community quantitative classification ORDINATION
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Temperate ice layer found in the upper area of Jima Yangzong Glacier,the headstream of Yarlung Zangbo River 被引量:1
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作者 Tong Zhang Minghu Ding +2 位作者 Cunde Xiao Dongqi Zhang Zhiheng Du 《Science Bulletin》 SCIE EI CAS CSCD 2016年第8期619-621,共3页
For the first time we investigate the basal thermal condition in the upper area of Jima Yangzong Glacier, the headstream of Yarlung Zangbo River, using ground-penetrating radar techniques. With common offset and commo... For the first time we investigate the basal thermal condition in the upper area of Jima Yangzong Glacier, the headstream of Yarlung Zangbo River, using ground-penetrating radar techniques. With common offset and common mid-point surveys we analyze the radar velocities in ice with respect to cold-temperate ice transi- tion surface (0.1751 0.0028 m ns-~) and ice-bedrock interface (0.1657 + 0.0033 m ns-a), indicating a radar velocity of 0.1410 4- 0.0154 m ns-1 for the temperate ice layer (16.6 ~ 1.8 m). We estimate that the temperate ice layer has a water content of around 6 % 4- 4 %, suggesting that the Jima Yangzong Glacier, previously known as continental-type, now possibly becomes polythermal. 展开更多
关键词 Jima Yangzong Glacier YarlungZangbo River - Ground-penetrating radar Radarvelocity - Englacial water content Polythermal
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Early Ordovician strongly peraluminous granite in the middle section of the Yarlung Zangbo junction zone and its geological significance 被引量:12
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作者 ZHANG ShiZhen LI FenQi +2 位作者 LI Yong LIU Wei QIN YaDong 《Science China Earth Sciences》 SCIE EI CAS 2014年第4期630-643,共14页
LA-ICP-MS zircon U-Pb isotopic dating and rock geochemical analysis were done of the Xarru granite in the middle section of the Yarlung Zangbo junction zone. Zircon 2-6pb/Z38u weighted mean ages of 474.9±2.3 and ... LA-ICP-MS zircon U-Pb isotopic dating and rock geochemical analysis were done of the Xarru granite in the middle section of the Yarlung Zangbo junction zone. Zircon 2-6pb/Z38u weighted mean ages of 474.9±2.3 and 478.3±1.7 Ma have been obtained for two gneiss granite samples respectively, which represent the formation age of the granite. This is the first discovery of the Early Ordovician magmatism in the Yarlung Zangbo junction zone. The rocks are high-K calcic-alkalic granite, contain tour- maline but not hornblende, with aluminum saturation index (ASI) of A/CNK〉I.1 (1.10-1.20), and are enriched in Rb, Th and U and relatively depleted in Ba, Nb, Sr, Zr, Ti and Eu. They are strongly peraluminous S-type granite, resulting from partial melting of argillaceous components in the crust in a syn-collisional setting. According to previous studies as well as the analy- sis in this paper, the formation of the Xarru granite is probably related to the Andean-type orogeny in the process of subduction of the Proto-Tethys Ocean towards the Gondwanaland, and it is a product of partial melting of the thickened upper crust as a result of collision between blocks or micro-blocks in the northern margin of the Gondwana supercontinent in the process of oceanic subduction. The Xarru granite is identified as the Early Ordovician granite, indicating that the wall rocks had probably formed in the Cambrian or Precambrian. 展开更多
关键词 A crustal basement may exist in the Xarru region. Yarlung Zangbo Junction Zone Early Ordovician strongly peraluminous granite collisional setting crustal basement
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Zircon SHRIMP geochronology and Nd-Pb isotopic characteristics of the meta-basalt in the central part of Tibetan Plateau's Qiangtang region 被引量:5
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作者 PENG ZhiMin GENG QuanRu +4 位作者 PAN GuiTang WANG LiQuan ZHANG Zhang CONG Feng GUAN JunLei 《Science China Earth Sciences》 SCIE EI CAS 2014年第3期428-438,共11页
A small-sized meta-basic rock system is discovered in Qilongwuru Gully of Central Qiangtang’s Shuanghu region and contains a meta-basalt and garnet-bearing plagioclase amphibolite.The zircon U/Pb age of this meta-bas... A small-sized meta-basic rock system is discovered in Qilongwuru Gully of Central Qiangtang’s Shuanghu region and contains a meta-basalt and garnet-bearing plagioclase amphibolite.The zircon U/Pb age of this meta-basalt by SHRIMP analysis is463.3±4.7 Ma,suggesting that this lava formed in the Middle Ordovician,and is consistent with that of the meta-basic rocks in the Taoxing Lake and Guoganjianian Mountain ophiolite found in the Qiangtang plate.As this lava system bears similar geochemistry to N-MORB,it might be a component of ophiolite that represents the trail of the extinction of the Proto-Tethys,suggesting that the formation of Proto-Tethys oceanic basin in the Longmu Co-Shuanghu suture zone could date as far back as to the Middle Ordovician.Isotopic geochemical analysis indicates that the magma source area consists of both depleted mantle(DM)and enriched mantle(EMII)end members and bears Dupal anomaly,similar to that of the Paleo-Tethys in the Neo-Tethys represented by the Yarlung-Tsangpo suture zone,the Paleo-Tethys represented by the Changning-Menglian suture zone,and the Paleo-Tethys in Sanjiang region.This suggests that they have inherited the attribute of the Proto-Tethys mantle domain,and the Longmu Co-Shuanghu suture zone may be a representative of the northern boundary of Gondwana. 展开更多
关键词 Tibetan Plateau's Qiangtang region meta-basalt zircon U-Pb age TETHYS Nd-Pb isotope
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Processes of initial collision and suturing between India and Asia 被引量:46
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作者 DING Lin Satybaev MAKSATBEK +7 位作者 CAI FuLong WANG HouQi SONG PeiPing JI WeiQiang XU Qiang ZHANG LiYun Qasim MUHAMMAD Baral UPENDRA 《Science China Earth Sciences》 SCIE EI CAS CSCD 2017年第4期635-651,共17页
The initial collision between Indian and Asian continents marked the starting point for transformation of land-sea thermal contrast,uplift of the Tibet-Himalaya orogen,and climate change in Asia.In this paper,we revie... The initial collision between Indian and Asian continents marked the starting point for transformation of land-sea thermal contrast,uplift of the Tibet-Himalaya orogen,and climate change in Asia.In this paper,we review the published literatures from the past 30 years in order to draw consensus on the processes of initial collision and suturing that took place between the Indian and Asian plates.Following a comparison of the different methods that have been used to constrain the initial timing of collision,we propose that the tectono-sedimentary response in the peripheral foreland basin provides the most sensitive index of this event,and that paleomagnetism presents independent evidence as an alternative,reliable,and quantitative research method.In contrast to previous studies that have suggested collision between India and Asia started in Pakistan between ca.55 Ma and50 Ma and progressively closed eastwards,more recent researches have indicated that this major event first occurred in the center of the Yarlung Tsangpo suture zone(YTSZ) between ca.65 Ma and 63 Ma and then spreading both eastwards and westwards.While continental collision is a complicated process,including the processes of deformation,sedimentation,metamorphism,and magmatism,different researchers have tended to define the nature of this event based on their own understanding,an intuitive bias that has meant that its initial timing has remained controversial for decades.Here,we recommend the use of reconstructions of each geological event within the orogenic evolution sequence as this will allow interpretation of collision timing on the basis of multidisciplinary methods. 展开更多
关键词 Timing of initial collision between the Indian and Asian continents Collision criteria Transform fault Subduction zone Magmatism Deformation
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Constraining the timing of the India-Asia continental collision by the sedimentary record 被引量:37
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作者 HU XiuMian WANG JianGang +2 位作者 AN Wei Eduardo GARZANTI LI Juan 《Science China Earth Sciences》 SCIE EI CAS CSCD 2017年第4期603-625,共23页
Placing precise constraints on the timing of the India-Asia continental collision is essential to understand the successive geological and geomorphological evolution of the orogenic belt as well as the uplift mechanis... Placing precise constraints on the timing of the India-Asia continental collision is essential to understand the successive geological and geomorphological evolution of the orogenic belt as well as the uplift mechanism of the Tibetan Plateau and their effects on climate,environment and life.Based on the extensive study of the sedimentary record on both sides of the Yarlung-Zangbo suture zone in Tibet,we review here the present state of knowledge on the timing of collision onset,discuss its possible diachroneity along strike,and reconstruct the early structural and topographic evolution of the Himalayan collided range.We define continent-continent collision as the moment when the oceanic crust is completely consumed at one point where the two continental margins come into contact.We use two methods to constrain the timing of collision onset:(1) dating the provenance change from Indian to Asian recorded by deep-water turbidites near the suture zone,and(2) dating the age of unconformities on both sides of the suture zone.The first method allowed us to constrain precisely collision onset as middle Palaeocene(59±l Ma).Marine sedimentation persisted in the collisional zone for another 20-25 Ma locally in southern Tibet,and molassic-type deposition in the Indian foreland basin did not begin until another 10-15 Ma later.Available sedimentary evidence failed to firmly document any significant diachroneity of collision onset from the central Himalaya to the western Himalaya and Pakistan so far.Based on the Cenozoic stratigraphic record of the Tibetan Himalaya,four distinct stages can be identified in the early evolution of the Himalayan orogen:(1) middle Palaeocene-early Eocene earliest Eohimalayan stage(from 59 to 52 Ma):collision onset and filling of the deep-water trough along the suture zone while carbonate platform sedimentation persisted on the inner Indian margin;(2) early-middle Eocene early Eohimalayan stage(from 52 to 41 or 35 Ma):filling of intervening seaways and cessation of marine sedimentation;(3) late Eocene-Oligocene late Eohimalayan stage(from 41 to 25 Ma):huge gap in the sedimentary record both in the collision zone and in the Indian foreland;and(4) late Oligocene-early Miocene early Neohimalayan stage(from 26 to 17 Ma):rapid Himalayan growth and onset of molasse-type sedimentation in the Indian foreland basin. 展开更多
关键词 India-Asia continental collision Timing of collision onset Himalayan orogeny Tibet Himalaya Sedimentary record
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Analysis of the Water Environmental Capacity of Zhongba-Nyingchi Section of the Yarlung Tsangpo River
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作者 ZHAO Xiang LIU Zhaofei +1 位作者 WANG Rui YAO Zhijun 《Journal of Resources and Ecology》 CSCD 2018年第6期690-699,共10页
The Yarlung Tsangpo River,the longest river in Tibet,houses most of the population and economy in Tibet Autonomous province.Under the rapid development of economy and society in Tibet,the pollution in the Yarlung Tsan... The Yarlung Tsangpo River,the longest river in Tibet,houses most of the population and economy in Tibet Autonomous province.Under the rapid development of economy and society in Tibet,the pollution in the Yarlung Tsangpo River basin has rapidly increased.Evaluating water quality and water environmental capacity is needed for water resource management in Tibet.This study used a single factor evaluation method to evaluate water quality of the Zhongba-Nyingchi section of the Yarlung Tsangpo River based on measured data of CODcr, NH3-N and TP in the study area.Based on these data,determinations of ideal water environmental capacity, emissions of pollutants and remaining water environmental capacity of the study area were made by a one-dimensional steady water quality model under either section-head control or cross-section control.The data indicate that most of the monitoring sections in the study area experienced good water quality.The three pollutants all had large remaining water environmental capacity generally,but TP exceeded state levels in the two upstream functional areas,and levels above state standards of CODcr and TP were found in several calculation cells of the two downstream functional areas.Therefore,emissions of pollutants need to be reduced to protect the water environment quality of the Yarlung Tsangpo River. 展开更多
关键词 The Yarlung Tsangpo River section-head control cross-section control ideal water environmental capacity emissions of pollutants remaining water environmental capacity
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