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Concept Planning of Ecological Landscapes on Urban Fringes——A Case Study of Landscape Concept Planning of Shiling Area in the Eastern New District of Chengdu City, Sichuan Province of China
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作者 廖春艳 沈一 《Journal of Landscape Research》 2011年第10期50-53,共4页
With Shiling Area of Eastern New District in Chengdu City as a background, concept design scheme was put forward from the perspective of ecological landscape through analyzing present development and ecological landsc... With Shiling Area of Eastern New District in Chengdu City as a background, concept design scheme was put forward from the perspective of ecological landscape through analyzing present development and ecological landscapes of the study area, applying philosophic thinking and Abstract concepts, and also combining with actual conditions of Chengdu, and meanwhile, concepts, orientation and functional structure of the eco-landscape concept planning were proposed. Key points of the planning were elaborated from 4 perspectives of spatial structure, traffic organization, spatial sequence and plant configuration to discuss spatial configuration of ecological landscapes on the fringes of Chengdu City, then further improve functions of ecological landscapes and quality of ecological environment, and put the concept planning into the construction practice of urban fringes. 展开更多
关键词 Urban FRINGES ECOLOGICAL landscapes Shiling area of eastern New District in Chengdu LANDSCAPE PLANNING
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Characteristics of Tight Sandstone Reservoirs and Controls of Reservoir Quality: A Case Study of He 8 Sandstones in the Linxing Area, Eastern Ordos Basin, China 被引量:5
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作者 GAO Xiangdong WANG Yanbin +4 位作者 LI Yong GUO Hui NI Xiaoming WU Xiang ZHAO Shihu 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2019年第3期637-659,共23页
Determining the process of densification and tectonic evolution of tight sandstone can help to understand the distribution of reservoirs and find relatively high-permeability areas.Based on integrated approaches of th... Determining the process of densification and tectonic evolution of tight sandstone can help to understand the distribution of reservoirs and find relatively high-permeability areas.Based on integrated approaches of thin section,scanning electron microscopy(SEM),cathode luminescence(CL),nuclear magnetic resonance(NMR),X-ray diffraction(XRD),N2 porosity and permeability,micro-resistivity imaging log(MIL)and three-dimensional seismic data analysis,this work discussed the reservoir characteristics of the member 8 of the Permian Xiashihezi Formation(He 8 sandstones)in the Linxing area of eastern Ordos Basin,determined the factors affecting reservoir quality,and revealed the formation mechanism of relatively high-permeability areas.The results show that the He 8 sandstones in the Linxing area are mainly composed of feldspathic litharenites,and are typical tight sandstones(with porosity<10%and permeability<1 mD accounting for 80.3%of the total samples).Rapid burial is the main reason for reservoir densification,which resulted in 61%loss of the primary porosity.In this process,quartz protected the original porosity by resisting compaction.The cementation(including carbonate,clay mineral and siliceous cementation)further densified the sandstone reservoirs,reducing the primary porosity with an average value of 28%.The calcite formed in the eodiagenesis occupied intergranular pores and affected the formation of the secondary pores by preventing the later fluid intrusion,and the Fe-calcite formed in the mesodiagenetic stage densified the sandstones further by filling the residual intergranular pores.The clay minerals show negative effects on reservoir quality,however,the chlorite coatings protected the original porosity by preventing the overgrowth of quartz.The dissolution of feldspars provides extensive intergranular pores which constitute the main pore type,and improves the reservoir quality.The tectonic movements play an important role in improving the reservoir quality.The current tectonic traces of the study area are mainly controlled by the Himalayan movement,and the high-permeability reservoirs are mainly distributed in the anticline areas.Additionally,the improvement degree(by tectonic movements)of reservoir quality is partly controlled by the original composition of the sandstones.Thus,the selection of potential tight gas well locations in the study area should be focused on the anticline areas with relatively good original reservoir quality.And the phenomena can be referenced for other fluvial tight sandstone basins worldwide. 展开更多
关键词 TIGHT gas RESERVOIR quality high-permeability RESERVOIRS Linxing area eastern ORDOS Basin
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Epidemiology of pediculosis capitis among schoolchildren in the eastern area of Bangkok,Thailand 被引量:3
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作者 Watcharawit Rassami Mayura Soonwera 《Asian Pacific Journal of Tropical Biomedicine》 SCIE CAS 2012年第11期901-904,共4页
Objective:To determine the prevalence of infestation with head lice in primary schoolchildren in the eastern area of Bangkok,Thailand.Methods:The present study was to determine the head lice infestation(Pediculosis) l... Objective:To determine the prevalence of infestation with head lice in primary schoolchildren in the eastern area of Bangkok,Thailand.Methods:The present study was to determine the head lice infestation(Pediculosis) levels in primary schoolchildren,during May,2011 to July, 2011,A total of 3747 schoolchildren aged 5-12 years old from 12 selected primary school of Ladkrabang district,the eastern area of Bangkok were examined for head lice.Pediculosis was defined as the presence of at least on living adult,nymph and viable egg.Results:The overall head lice infestation rate was 23.32%and infestation rate was higher in girls(47.12%) than in boys(0%).The infestation rate among schoolchildren varied from 12.62%to 29.76%.The infestation rate among girls varied from 26.07%(12 years old group) to 55.89%(8 years old group).Conclusions: Pediculosis is a common public healtli problem affecting primary schoolchildren in eastern area of Bangkok and those levels are epidemic importance. 展开更多
关键词 PEDICULOSIS capitis Epidermiology SCHOOLCHILDREN eastern area of BANGKOK
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Spatio-temporal Dynamic Patterns of Rural Area Development in Eastern Coastal China 被引量:4
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作者 LIU Yansui WANG Guogang ZHANG Fugang 《Chinese Geographical Science》 SCIE CSCD 2013年第2期173-181,共9页
The aim of this study is to evaluate the current state of rural area development at the county level in the eastern coastal China. An evaluation index system including 18 factors was developed, and a rural development... The aim of this study is to evaluate the current state of rural area development at the county level in the eastern coastal China. An evaluation index system including 18 factors was developed, and a rural development index (RDI) was constructed to evaluate rural development state in 2000, 2004, and 2008. The quantitative evaluation indicated the following results. 1) This study derived four dominating components by means of principal component analysis, which can explain 78.2% of the total information, namely agricultural production input, the basic condition of agriculture, the comparative effectiveness of grain production, and the household′s own basic conditions. 2) Since the turn of the new millennium, the rural area in the eastern coastal China has experienced a rapid development in general. Well developed, developed, moderately developed and undeveloped rural areas respectively occupied 29.32%, 22.33%, 21.91%, and 10.51% in 2008. 3) The countryside had maintained a sound momentum of developing trend between 2000 and 2008, while the rural development in the eastern coastal China lacked sustainability. And 4) industrialization, urbanization, original economic basis, and location are four major driving forces of the disparity of rural area development in the eastern coastal China. Given these results, the strategies and policies for the improvement of each rural group were put forward. 展开更多
关键词 rural area development rural development evaluation new countryside construction eastern coastal China
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Magma Mixing and Mingling for Xiangjiananshan Granitic batholith at eastern area of the East Kunlun Orogenic Belt 被引量:5
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作者 CHEN Guochao PEI Xianzhi +4 位作者 LI Ruibao LI Zuochen LIU Chenjun CHEN Youxin PEI Lei 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2017年第S1期63-,共1页
The East Kunlun Orogenic Belt(EKOB)in northeast margin of the Qinghai-Tibetan Plateau is an important part of the Central Orogenic System(COS).During the long-time geological evolution,complicated tectono
关键词 area Magma Mixing and Mingling for Xiangjiananshan Granitic batholith at eastern area of the East Kunlun Orogenic Belt
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Relationship between diversity of forest plant and community dynamics in eastern mountain area of Heilongjiang Province, China 被引量:1
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作者 WANG Qing-gui XING Ya-juan +1 位作者 ZHOU Xiao-feng HAN Shi-jie 《Journal of Forestry Research》 SCIE CAS CSCD 2006年第4期289-292,共4页
The biodiversity was studied in 26 communities with different structures in Maoershan National Park and Liangshui Natural Reserve of Northeast Forestry University in Heilongjiang Province, China. Composition index (C... The biodiversity was studied in 26 communities with different structures in Maoershan National Park and Liangshui Natural Reserve of Northeast Forestry University in Heilongjiang Province, China. Composition index (CI) was taken as a parameter to quantify the community dynamics, which can nicely describe forest community dynamics, meanwhile, the relationship between diversity and community dynamics were also investigated and analyzed. Results showed that the total number species of community, richness, evenness, and Shannon-Wiener diversity index were obviously different in every community. The richness decreased with the increasing CI of every community, which means richness was in inverse proportion to community dynamics. The Shannon-Wiener index of every community increased from the initial stage to the middle stage of succession, and then decreased in the climax stage. The coverage weighted foliage-height diversity index increased along with the increase of CI, which was similar as the oattem diversity. 展开更多
关键词 eastern mountain area of Heilongjiang province Shannon-wiener diversity Pattern diversity Community dynamics
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Ground water hydrochemical characteristics: seawater intruded area in eastern and southern coast of Laizhou Bay 被引量:1
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作者 ZHANG Zu-lu, JIANG Lu-guang, YANG Li-yuan, QI Yong-hua (Department of Geography, Shandong Normal University, Jinan 250014, China) 《Journal of Geographical Sciences》 SCIE CSCD 2001年第3期350-355,共6页
Eastern and southern coastal zones of Laizhou Bay are the most representative seawater intruded areas in the world, with two intrusion sources of contemporary seawater and paleobrine. In order to reveal the complicate... Eastern and southern coastal zones of Laizhou Bay are the most representative seawater intruded areas in the world, with two intrusion sources of contemporary seawater and paleobrine. In order to reveal the complicated hydrochemical changing process and the mechanism of fresh groundwater being polluted by saltwater, we conducted long-term observation and hydrochemical analysis at four observing sections of typical salt-fresh water transitional zone. The study indicates that seawater and brine intrusion processes have different hydrochemical features, and that ion exchange and adsorption actions between water and aquifer produce great influence on the intrusion. 展开更多
关键词 seawater intrusion eastern and southern coastal areas of Laizhou Bay hydrochemical characteristics of groundwater
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Discovery of Lorandite TlAsS_2 at the Distal Au-Tl Deposit in a Skarn system,Fengshan Area,Middle-Lower Yangtze River,Eastern China 被引量:6
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作者 XIE Guiqing MAO Jingwen +2 位作者 HAN Yingxiao JIAN Wei HAN Jingyi 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2017年第4期1493-1494,共2页
Thallium has been used geochemical exploration of gold deposits. However, as an indicator element in searching for hydrothermal the T1 minerals and mineralization are rare in nature. Lorandite T1AsS2, a relatively un... Thallium has been used geochemical exploration of gold deposits. However, as an indicator element in searching for hydrothermal the T1 minerals and mineralization are rare in nature. Lorandite T1AsS2, a relatively uncommon mineral, has been dominantly discovered in some Carlin gold deposits, and minor Sb- Hg, U and Pb-Zn-Ag deposits. 展开更多
关键词 As Pb Discovery of Lorandite TlAsS2 at the Distal Au-Tl Deposit in a Skarn system Fengshan area Middle-Lower Yangtze River eastern China
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Temporal and Spatial Variations of ET 0 and Sensitivity Coefficients in Spring-summer in Eastern Agricultural Areas of Qinghai,China 被引量:1
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作者 ZHAO Lu LIANG Chuan +2 位作者 CUI Ningbo WEI Renjuan YANG Haoxiang 《Journal of Mountain Science》 SCIE CSCD 2012年第6期817-826,共10页
Reference crop evapotranspiration(ET 0) is a key parameter to calculate crop water requirements.In the paper,ET 0 during 1960-2005 was calculated with FAO-56 PM in eastern agricultural areas of Qinghai,China.Then the ... Reference crop evapotranspiration(ET 0) is a key parameter to calculate crop water requirements.In the paper,ET 0 during 1960-2005 was calculated with FAO-56 PM in eastern agricultural areas of Qinghai,China.Then the sensitivity coefficients of ET 0 to meteorological variables were estimated through the nondimensional partial derivative in FAO-56 PM.Results show that the mean annual ET 0 of the whole area is 904 mm,and ET 0 portrays a very significant decrease during the 46 years.In spatial,ET 0 decreases from southeast to northwest,firstly increases then decreases from southwest to northeast.Through sensitivity analysis,in spring the most sensitive variable is relative humidity,while in summer is temperature.The temperature,sunshine duration and wind speed sensitivity coefficients(S(TA),S(n),S(u)) are higher in middle areas as opposed to surrounding areas,while the relative humidity sensitivity coefficient(S(RH)) has an opposite distribution rule. 展开更多
关键词 ET0 FAO-56 PM Sensitivity coefficients eastern agricultural areas of Qinghai
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Liquid immiscibility recorded in melt inclusions within corundum from alkaline basalt,Changle area,Shandong province,Eastern China 被引量:4
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作者 刘吉强 倪培 +1 位作者 沈昆 丁俊英 《岩石学报》 SCIE EI CAS CSCD 北大核心 2007年第1期125-130,共6页
Abundant melt-and fluid inclusions occur in corundum megacrysts of alkaline basalt from the Changle area,Shandong province,eastern China.One type of melt inclusions,i.e.muhiphase melt inclusions(glass+bubbles+daughter... Abundant melt-and fluid inclusions occur in corundum megacrysts of alkaline basalt from the Changle area,Shandong province,eastern China.One type of melt inclusions,i.e.muhiphase melt inclusions(glass+bubbles+daughter minerals)were identified,which occur along growth zones of host corundum megacrysts.Microthermometry and laser Raman microprobe analysis were performed on the melt inclusions.The bubbles within the melt inclusions are confirmed to be CO_2-rich phase and the daughter minerals are probably silicates,such as augite and okenite.The results of high temperature homogenization experiment strongly suggest that two immiscible melts,i.e.a H_2O-and CO_2-rich melt and an anhydrous and CO_2-poor melt were trapped by melt inclusions in corundum megacryst. 展开更多
关键词 中国 山东 昌乐地区 碱性玄武岩 刚玉 岩浆不混溶作用
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Monitoring Soil Salt Content Using HJ-1A Hyperspectral Data: A Case Study of Coastal Areas in Rudong County, Eastern China 被引量:5
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作者 LI Jianguo PU Lijie +5 位作者 ZHU Ming DAI Xiaoqing XU Yan CHEN Xinjian ZHANG Lifang ZHANG Runsen 《Chinese Geographical Science》 SCIE CSCD 2015年第2期213-223,共11页
Hyperspectral data are an important source for monitoring soil salt content on a large scale. However, in previous studies, barriers such as interference due to the presence of vegetation restricted the precision of m... Hyperspectral data are an important source for monitoring soil salt content on a large scale. However, in previous studies, barriers such as interference due to the presence of vegetation restricted the precision of mapping soil salt content. This study tested a new method for predicting soil salt content with improved precision by using Chinese hyperspectral data, Huan Jing-Hyper Spectral Imager(HJ-HSI), in the coastal area of Rudong County, Eastern China. The vegetation-covered area and coastal bare flat area were distinguished by using the normalized differential vegetation index at the band length of 705 nm(NDVI705). The soil salt content of each area was predicted by various algorithms. A Normal Soil Salt Content Response Index(NSSRI) was constructed from continuum-removed reflectance(CR-reflectance) at wavelengths of 908.95 nm and 687.41 nm to predict the soil salt content in the coastal bare flat area(NDVI705 < 0.2). The soil adjusted salinity index(SAVI) was applied to predict the soil salt content in the vegetation-covered area(NDVI705 ≥ 0.2). The results demonstrate that 1) the new method significantly improves the accuracy of soil salt content mapping(R2 = 0.6396, RMSE = 0.3591), and 2) HJ-HSI data can be used to map soil salt content precisely and are suitable for monitoring soil salt content on a large scale. 展开更多
关键词 soil salt content normalized differential vegetation index(NDVI) hyperspectral data Huan Jing-Hyper Spectral Imager(HJ-HSI) coastal area eastern China
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Multiple Phases of Mafic Magmatism in Gyangze-Kangma Area: Implications for the Tectonic Evolution of Eastern Tethyan Himalaya 被引量:1
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作者 WANG Yaying ZENG Lingsen +3 位作者 GAO Li-E ZHAO Linghao GAO Jiahao SHANG Zhen 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2016年第S1期129-130,共2页
A number of E-W trending subparallel mafic dikes of diabase composition occurred in Gyangze-Kangma area,eastern Tethyan Himalaya,southern Tibet.They intruded into the Tethyan Himalaya sedimentary sequence.Whether they... A number of E-W trending subparallel mafic dikes of diabase composition occurred in Gyangze-Kangma area,eastern Tethyan Himalaya,southern Tibet.They intruded into the Tethyan Himalaya sedimentary sequence.Whether they belong to the;32 Ma Comei LIP(Zhu et al.,2009)or 展开更多
关键词 Implications for the Tectonic Evolution of eastern Tethyan Himalaya Multiple Phases of Mafic Magmatism in Gyangze-Kangma area ROCK
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Geochemical Characteristics of Cenozoic Basaltic High-K Volcanic Rocks from Maguan Area, Eastern Tibet 被引量:7
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作者 魏启荣 王江海 《Chinese Journal Of Geochemistry》 EI CAS 2004年第1期57-64,共8页
The major element, trace element and Nd-Sr isotopic composition of Cenozoic basaltic volcanic rocks from the Maguan area, eastern Tibet, indicates that the volcanic rocks are enriched in alkalis, especially K (K-2O up... The major element, trace element and Nd-Sr isotopic composition of Cenozoic basaltic volcanic rocks from the Maguan area, eastern Tibet, indicates that the volcanic rocks are enriched in alkalis, especially K (K-2O up to {3.81%}) and depleted in Ti (TiO-2={1.27%}-{2.00%}). These rocks may be classified as two groups, based on their Mg+# numbers: one may represent primary magma (Mg+# numbers from 68 to 69), and the other, the evolved magma (Mg+# numbers from 49 to 57). Their REE contents are very high (∑REE={155.06}-{239.04}μg/g). Their REE distribution patterns are of the right-inclined type, characterized by LREE enrichment [(La/Yb)-N={12.0}-{19.2}], no Ce anomaly (Ce/Ce+*={1.0}), and weak negative Eu anomaly (Eu/Eu+*={0.9}). The rocks are highly enriched in Rb, Sr and Ba ({59.5}-{93.8} μg/g, 732-999 μg/g, and 450-632 μg/g, respectively), high in U and Th ({1.59}-{2.31} μg/g and {4.73}-{8.16} μg/g, respectively), and high in Nb, Ta, Zr and Hf (70-118 μg/g, {3.72}-{5.93} μg/g, 215-381 μg/g, and {5.47}-{9.03} μg/g, respectively). In the primitive mantle-normalized incompatible element spidergram, Nb, Ta, Zr, Hf and P show positive anomalies, whereas Ba, Ti and Y show negative anomalies. The {{}+{87}Sr/+{86}Sr} ratios range from {0.704029} to {0.704761}; {{}+{143}Nd/+{144}Nd} from {0.512769} to {0.512949}; and εNd from {+2.6} to {+6.1}. These geochemical features might suggest that the potential source of the basaltic high-K volcanic rocks in the Maguan area is similar to the OIB-source mantle of Hawaii and Kergeulen volcanic rocks. 展开更多
关键词 地球化学 新生代 玄武岩 火山岩 同位素
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Fluid migration paths in the marine strata of typical structures in the western Hubei-eastern Chongqing area,China 被引量:3
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作者 Xu Guosheng Liang Jiaju +4 位作者 Gong Deyu Wang Guozhi Yuan Haifeng Cao Junxing Zhang Chengfu 《Petroleum Science》 SCIE CAS CSCD 2013年第1期1-18,共18页
The western Hubei-eastern Chongqing area is an important prospective zone for oil and gas exploration in the central Yangtze area. Three representative structures, the Xinchang structure, Longjuba gas-bearing structur... The western Hubei-eastern Chongqing area is an important prospective zone for oil and gas exploration in the central Yangtze area. Three representative structures, the Xinchang structure, Longjuba gas-bearing structure and the Jiannan gas field, were selected to analyze biomarker parameters in marine strata and to examine various types of natural gas and hydrocarbon sources. Fluid inclusions; carbon, oxygen, and strontium isotopic characteristics; organic geochemical analysis and simulation of hydrocarbon generation and expulsion history of source rocks were used for tracing fluid migration paths in marine strata of the study area. The Carboniferous-Triassic reservoirs in three typical structures all experienced at least two stages of fluid accumulation. All marine strata above the early Permian were shown to have fluids originating in the Permian rocks, which differed from the late stage fluids. The fluids accumulated in the late Permian reservoirs of the Xinchang structure were Cambrian fluids, while those in the late Carboniferous reservoirs were sourced from a combination of Silurian and Cambrian fluids. A long-distance and large-scale cross-formational flow of fluids destroyed the preservation conditions of earlier accumulated hydrocarbons. A short-distance cross-formational accumulation of Silurian fluids was shown in the late Permian reservoirs of the Longjuba structure with favorable hydrocarbon preservation conditions. The fluid accumulation in the Carboniferous reservoirs of the Jiannan structure mainly originated from neighboring Silurian strata with a small amount from the Cambrian strata. As a result, the Jiannan structure was determined to have the best preservation conditions of the three. Comparative analysis of fluid migration paths in the three structures revealed that the zone with a weaker late tectonism and no superimposition and modification of the Upper and Lower Paleozoic fluids or the Upper Paleozoic zone with the fluid charging from the Lower Paleozoic in the western Hubei-easteru Chongqing area are important target areas for future exploration. 展开更多
关键词 Western Hubei-eastern Chongqing area marine strata geochemical tracer fluid migration path
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Pressure-temperature Evolution of the Metapelites in the Motuo Area, the Eastern Himalayan Syntaxis
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作者 DONG Hanwen XU Zhiqin +1 位作者 LI Yuan LIU Zhao 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2014年第2期544-557,共14页
The Motuo area is located in the east of the Eastern Himalayan Syntaxis.There outcrops a sequence of high-grade metamorphic rocks,such as metapelites.Petrology and mineralogy data suggest that these rocks have experie... The Motuo area is located in the east of the Eastern Himalayan Syntaxis.There outcrops a sequence of high-grade metamorphic rocks,such as metapelites.Petrology and mineralogy data suggest that these rocks have experienced three stages of metamorphism.The prograde metamorphic mineral assemblages (M1) are mineral inclusions (biotite + plagioclase + quartz ± sillimanite ± Fe-Ti oxides) preserved in garnet porphyroblasts,and the peak metamorphic assemblages (M2) are represented by garnet with the lowest Xsps values and the lowest XFe# ratios and the matrix minerals (plagioclase + quartz ± K-feldspar + biotite + muscovite + kyanite ± siilimanite),whereas the retrograde assemblages (M3) are composed of biotite + plagioclase + quartz symplectites rimming the garnet porphyroblasts.Thermobarometric computation shows that the metamorphic conditions are 562-714℃ at 7.3-7.4 kbar for the M1 stage,661-800℃ at 9.4-11.6 kbar for the M2 stage,and 579-713℃ at 5.5-6.6 kbar for the M3 stage.These rocks are deciphered to have undergone metamorphism characterized by clockwise P-T paths involving nearly isothermal decompression (ITD) segments,which is inferred to be related to the collision of the India and Eurasia plates. 展开更多
关键词 metamorphic rocks P-T path Motuo area the eastern Himalayan Syntaxis
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Deep-derived enclaves (belonging to middle-lower crust metamorphic rocks) in the Liuhe-Xiangduo area, eastern Tibet: Evidence from petrogeochemistry 被引量:2
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作者 魏启荣 李德威 +1 位作者 郑建平 王江海 《Chinese Journal Of Geochemistry》 EI CAS 2006年第3期245-254,共10页
Petrological and geochemical studies of deep-derived enclaves from the Liuhe-Xiangduo area, eastern Tibet, showed that the enclaves involve five types of rocks, i.e., garnet diopsidite, garnet amphibolite, garnet horn... Petrological and geochemical studies of deep-derived enclaves from the Liuhe-Xiangduo area, eastern Tibet, showed that the enclaves involve five types of rocks, i.e., garnet diopsidite, garnet amphibolite, garnet hornblendite, amphibolite and hornblendite, whose main mineral assemblages are Grt+Di+Hbl, Grt+Pl+Hbl+Di, Grt+Hbl+Pl, Pl+Hbl, and Hbl+Bt, respectively. The enclaves exhibit typical crystalloblastic texture, and growth zones are well developed in garnet (Grt) in the enclaves. In view of major element geochemistry, the deep|derived enclaves are characterized by high MgO and FeO+*, ranging from {12.00%} to {12.30%} and {8.15%} to {10.94%}, respectively. The protolith restoration of metamorphic rocks revealed that the enclaves belong to ortho-metamorphic rocks. The REE abundances vary over a wide range, and ∑REE ranges from {53.39} to {129.04} μg/g. The REE patterns slightly incline toward the HREE side with weak LREE enrichment. The contents of Rb, Sr, and Ba range from {8.34} to 101μg/g, 165 to 1485 μg/g, and 105 to 721 μg/g, respectively. The primitive mantle-normalized spider diagrams of trace elements show obvious negative Nb, Ta, Zr and Hf anomalies. Sr-Nd isotopic compositions of the enclaves indicated that the potential source of deep-derived enclaves is similar to the depleted|mantle, and their {({}+{87}Sr/+{86}Sr)-i} ratios vary from {0.706314} to {0.707198}, {({}+{147}Nd/+{144}Nd)-i} ratios from {0.512947} to {0.513046}, and {ε-{Nd}(T)} values from {+7.0} to {+9.0}, respectively. The potential source of the enclaves is obviously different from the EM2-type mantle from which high-K igneous rocks stemmed (the host rocks), i.e., there is no direct genetic relationship between the enclaves and the host rocks. Deep-derived enclaves in the host rocks belong to mafic xenoliths, and those in the Liuhe-Xiangduo area, eastern Tibet, are some middle-lower crust ortho-metamorphic rocks which were accidentally captured at 20-50 km level by rapidly entrained high-temperature high-K magma, whose source is considered to be located at 50-km depth or so. 展开更多
关键词 地球化学 西藏 岩石 变质岩
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Coral Ba/Ca and Mn/Ca Ratios as Proxies of Precipitation and Terrestrial Input at the Eastern Offshore Area of Hainan Island
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作者 JIANG Qiaowen CAO Zhimin +3 位作者 WANG Daoru LI Yuanchao WU Zhongjie NI Jianyu 《Journal of Ocean University of China》 SCIE CAS CSCD 2017年第6期1072-1080,共9页
Geochemical ratios in coral reef skeletons could be used as proxies to reconstruct past climatological and environmental records in data-poor regions. Using a 103-year data set(1902 to 2005), the annual variations in ... Geochemical ratios in coral reef skeletons could be used as proxies to reconstruct past climatological and environmental records in data-poor regions. Using a 103-year data set(1902 to 2005), the annual variations in Ba/Ca and Mn/Ca ratios of Porites lutea skeletons at an eastern offshore area of Hainan Island(19?12'28.4''N, 110?37'38.8''E) were analyzed using inductively coupled plasma-optic emission spectrometry(ICP-OES). The analysis results showed that Ba/Ca ratios varied from a minimum of 3.120 μmol mol^(-1) in 1903 to a maximum of 10.064 μmol mol^(-1) in 1944, with an average of 5.256 μmol mol^(-1). Mn/Ca ratios varied from 0.206 to 5.708 μmol mol^(-1) with an annual average of 1.234 μmol mol^(-1), with peak values in 2001, 1964 and 1932, that correlated with strong rainfall events caused by typhoons. Variation in Ba/Ca and Mn/Ca ratios were compared with available river discharge and precipitation records, providing insight into past climatological events. Human activities and their indirect effects could impact the strength of the relationship between Ba/Ca and Mn/Ca ratios and observed precipitation and terrestrial input in the future. 展开更多
关键词 PORITES lutea eastern offshore area of Hainan Island Ba/Ca and Mn/Ca ratios terrigenous INPUT PRECIPITATION climate proxy records
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Modern sea level changes of the Eastern China Seas and their influences on coastal areas
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作者 Liu ZhenxiaFirst Institute of Oceanography, SOA, Qingdao 266003, China 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 1992年第1期52-59,共8页
The statistics of tidal gauging records showed that the mean sea level of the China Seas has risen for 14 cm in past 100 years. The annual mean sea levels of the Eastern China Seas have been rising at a speed of about... The statistics of tidal gauging records showed that the mean sea level of the China Seas has risen for 14 cm in past 100 years. The annual mean sea levels of the Eastern China Seas have been rising at a speed of about 0.21 -0.23 cm/a since 1960. The annual mean sea levels of the Eastern China Seas in 1989 were 1.45 cm higher than that in 1988 on average.The sea level rise may cause the damage of the dynamical balance of the natural environments in the coastal area? and form or strengthen many coastal disasters, such as storm-tide catastrophic events, sea water invasion landward, soil salinization in coastal lowland and plains, and beach erosion retreat. 展开更多
关键词 sea level: eastern China Seas coastal area.
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Tomography for Q of the Eastern Section of the Tianshan Area from High-frequency Attenuation of S-wave
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作者 Li Jin Zhou Longquan +1 位作者 Wang Huilin Xiang Yuan 《Earthquake Research in China》 CSCD 2018年第1期28-39,共12页
Based on the waveform data of 5,076 local earthquakes recorded at 25 stations in Xinjiang during the period from 2009 to 2014 and the observation reports provided by the Xinjiang Digital Seismic Network,a data set of ... Based on the waveform data of 5,076 local earthquakes recorded at 25 stations in Xinjiang during the period from 2009 to 2014 and the observation reports provided by the Xinjiang Digital Seismic Network,a data set of 19,140 attenuation factors t*is obtained by fitting the high-frequency attenuation of S-wave spectra with a genetic algorithm. The spatial distribution of Q_S is determined by inverting the t*data with seismic tomography. The results show that the average Q0 in eastern Tianshan is 520,and there is a significant correlation between the Q_S value distribution or attenuation characteristics it disclosed and the surface structure of the study area. The Q_S value is lower in the intersection area of the mountain basin which is located on the north and south sides of the Tianshan Mountains,and the high Q_S distribution is more concentrated inside the Tianshan orogenic belt. The M≥6. 0 earthquakes have been basically located in the Low-Q_S region since 1900. 24 high heat flow points in eastern Tianshan are located at the north and south of Tianshan Mountains where low Q_S exists,indicating a negative correlation. In addition,there is a positive correlation between the velocity structure and the attenuation structure in the study area,which reflects the consistency of the 2-D attenuation structure with the velocity structure and the two-dimensional density structure. 展开更多
关键词 eastern SECTION of the TIANSHAN area HIGH-FREQUENCY ATTENUATION of S-WAVE ATTENUATION operator t* Q TOMOGRAPHY
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Discovery and Geological Significance of Early Carboniferous High-Mg Diorite in the Balikun Area, Eastern Tianshan
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作者 LUO Jinglan WANG Chong 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2020年第S01期39-39,共1页
The granodiorites,monzogranites and diorites are widely developed in the Balikun area of Eastern Tianshan Orogen.Of which,LA–ICP–MS zircon U-Pb isotopic dating from the diorites revealed that they were emplaced at 3... The granodiorites,monzogranites and diorites are widely developed in the Balikun area of Eastern Tianshan Orogen.Of which,LA–ICP–MS zircon U-Pb isotopic dating from the diorites revealed that they were emplaced at 327~333 Ma,representing an important period of magmatism in the Early Carboniferous.Geochemically,they are characterized by moderate SiO2(51.33–62.48 wt%),high but variable MgO(2.04–11.16 wt%,average 5.35),higher Mg#(40–73)and TiO2(0.67–1.29 wt%),Na2O/K2O(1.39–2.95)as well as variable Cr(2.49–675 ppm)and Ni(1.31–174 ppm),showing a geochemistry similar to those of high-Mg diorites or sanukitoids.In addition,they are enriched in the LILE,poor HFSE with an evident negative Nb anomalies and a REE pattern of moderate fractionator between LREE and HREE without or weak negative Eu anomalies.TheirεHf(t)are positive(+3.63–+15.65),suggesting a source from the depleted mantle.In addition,they have high TiO2 and Pb,and large quantity of amphibolite and biotite,indicating that they were most likely derived from the partial melting of depleted mantle metasomatized by the slabderived melt under a hydrous condition.Consequently,combined with the contemporary volcanics and granitoids formed in the island arc settings,we proposed that the subduction was continued till Early Carboniferous in the Bogda-Harlik tectonic belt.After that,wide occurrence of the post-collisional A-type granites and mafic-ultramafic intrusions indicate this tectonic belt entered the post-collisional environment from Late Carboniferous to Permian. 展开更多
关键词 high-Mg diorites U-Pb dating GEOCHEMISTRY PETROGENESIS Balikun area in eastern Tianshan
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