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离子交换法分离硼 被引量:17
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作者 肖应凯 刘卫国 +1 位作者 肖云 G.H.Swihart 《分析化学》 SCIE EI CAS CSCD 北大核心 1997年第11期1359-1359,共1页
关键词 离子交换法 IRA743树脂 吸附
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硼特效树脂离子交换法分离硼的研究 被引量:24
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作者 肖应凯 刘卫国 +1 位作者 肖云 G.H.Swihart 《盐湖研究》 CSCD 1997年第2期1-6,共6页
本文对AmberliteIRA743硼特效树脂交换分离础的特性及其影响因素进行了研究.它适用于各种地质作品中硼的分离提取,特别是在硼同位素地球化学研究时。必须进行础纯化的场合。
关键词 分离 硼特效树脂 离子交换 地质样品
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硼溶液蒸发过程中硼的挥发及硼同位素分馏 被引量:5
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作者 肖应凯 王岚 +2 位作者 R.D.VockeJr G.H.Swihart Y.Xiao 《盐湖研究》 CSCD 1997年第1期28-38,共11页
用蒸发实验研究了浓度为10-6级的硼在水和稀HCl溶液蒸发时的挥发度、同位素分馏和甘露醇的影响。结果表明,在溶液中有等摩尔的甘露醇和Cs都存在的条件下,硼才能在蒸发时和蒸干后保持定量回收;硼在不加入甘露醇或Cs的稀HCl溶液中蒸发... 用蒸发实验研究了浓度为10-6级的硼在水和稀HCl溶液蒸发时的挥发度、同位素分馏和甘露醇的影响。结果表明,在溶液中有等摩尔的甘露醇和Cs都存在的条件下,硼才能在蒸发时和蒸干后保持定量回收;硼在不加入甘露醇或Cs的稀HCl溶液中蒸发时也能定量回收,但是不能蒸干;若要蒸干.必须加入等摩尔的甘露醇,才能保持硼的定量回收。蒸发液和残留液的同位素测定表明,11B仇先从近中性和酸性溶液的蒸发中贫化。此结果对于硼需要预富集的过程是非常重要的。 展开更多
关键词 硼溶液 蒸发过程 挥发 硼同位素 分馏
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不连续岩体-拱坝系统的动力过程数值模拟方法 被引量:3
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作者 蔡永恩 罗纲 +3 位作者 刘今朝 李青松 张伯艳 陈厚群 《岩土力学》 EI CAS CSCD 北大核心 2004年第z2期361-365,共5页
提出了一种分析三维不连续变形块体系统动力学过程和建坝的数值方法,该方法不但能够模拟位移不连续面在地震载荷作用下的张开和大尺度的摩擦滑移,而且还能给出不连续面上安全系数的分布和随时间的变化。通过有 2 个块体组成的系统验证... 提出了一种分析三维不连续变形块体系统动力学过程和建坝的数值方法,该方法不但能够模拟位移不连续面在地震载荷作用下的张开和大尺度的摩擦滑移,而且还能给出不连续面上安全系数的分布和随时间的变化。通过有 2 个块体组成的系统验证了所提出的方法的正确性,同时用它分析了一个具有断层和伸缩缝的拱坝系统模型在地震载荷下的动力反应。 展开更多
关键词 岩体-拱坝系统 不连续变形 动力过程 数值模拟 安全系数
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华北太行山北段高于庄组微古植物的新发现(英文) 被引量:1
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作者 徐兆良 S.M.AWRAMIK 《Acta Botanica Sinica》 CSCD 2001年第3期295-311,共17页
长城群高于庄组主要分布于我国华北地区 ,地质年龄约在 14~ 16亿年。主要描述了华北太行山北段灵邱县境内高于庄组白云岩中的层状和扁豆状透镜体燧石及穹隆式叠层石的黑色燧石中的颤藻、念珠藻和色球藻植物的 8个新种和 3个未定种 ,其... 长城群高于庄组主要分布于我国华北地区 ,地质年龄约在 14~ 16亿年。主要描述了华北太行山北段灵邱县境内高于庄组白云岩中的层状和扁豆状透镜体燧石及穹隆式叠层石的黑色燧石中的颤藻、念珠藻和色球藻植物的 8个新种和 3个未定种 ,其中还有两个新修订属。这些新的种群再加上前人在高于庄组地层中已报道的汇成了近 10 0个种生物组合 ,进一步证明高于庄组是地球上中元代微化石类群最丰富的产地之一。以下是该组新发现和新修订的分类类群 :颤藻科 (Oscillatoriaceae) :Eophormidiumorculiformissp .nov.,E .sp .,Siphonophycuscaudataceoussp .nov.,Palaeolyngbyacomplanatasp .nov.,P .capitatasp .nov.,P .sp .,Oscillatoriopsissp .;念珠藻科 (Nosto caceae) :Veteronostocalevaginatasp .nov.;色球藻科 (Chroococcaceae) :Maculosphaeragigantasp .nov .,Gloeotheceopsisgrandissp .nov .;分类位置未定的类群 :Myxococcoideslimpidasp . 展开更多
关键词 华北 太行山 高于庄组 微化石 微古植物
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Andean adakites:three ways to make them安第斯埃达克岩:三种成因模式 被引量:98
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作者 RobertWKAY SuzanneMahlburgKAY 《岩石学报》 SCIE CAS CSCD 北大核心 2002年第3期303-311,共9页
在安第斯埃达克岩是常见的。由这种岩石的痕量元素特征揭示的高压组成矿物,表明其有三种可能的成因。这三种成因按相对重要性依次为:安第斯地壳的构造加厚;弧前壳的俯冲-侵蚀;年轻洋壳的俯冲。在过去300Ma,每种成因模式的埃达克岩... 在安第斯埃达克岩是常见的。由这种岩石的痕量元素特征揭示的高压组成矿物,表明其有三种可能的成因。这三种成因按相对重要性依次为:安第斯地壳的构造加厚;弧前壳的俯冲-侵蚀;年轻洋壳的俯冲。在过去300Ma,每种成因模式的埃达克岩在智利-阿根廷安第斯地区均有喷发。它们的产状与智利-阿根廷边缘快速变化的构造背景中特定构造条件和事件相吻合。埃达克岩在过去安第斯边缘的产状可望成为矿化的优异构造标志,也可用于指导找矿。 展开更多
关键词 埃达克岩 成因模式 痕量元素 地壳 俯冲侵蚀 构造事件
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全球大地热流-岩石生热率关系综合分析 被引量:6
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作者 黄少鹏 《地球物理学报》 SCIE EI CAS CSCD 北大核心 1998年第S1期26-33,共8页
大地热流分析是研究大地构造地球动力学和地壳化学组成的一个重要手段通过对全球范围大陆地区大地热流和岩石放射性生热率数据的综合统计分析探讨地壳一地慢热流配分统计结果揭示,全球尺度显生亩地质构造区热流与岩石生热率之间不存在... 大地热流分析是研究大地构造地球动力学和地壳化学组成的一个重要手段通过对全球范围大陆地区大地热流和岩石放射性生热率数据的综合统计分析探讨地壳一地慢热流配分统计结果揭示,全球尺度显生亩地质构造区热流与岩石生热率之间不存在简单的线性关系,但两者在隐生宙地盾区却具有明显正相关关系从大地热流-岩石生热率关系在显生亩地区和在隐生宙地区的差异可以大致确定壳-幔热流成分的变化范围取地壳厚度为30-50km,根据前寒武地盾区热流与生热率之间的统计关系可以进一步推测地壳岩石中放射性生热元素的平均丰度范围分别为铀(0.5—1.6)×10-6,钍(1.8-6.1)×10-6,氧化钾0.6%-1.9%. 展开更多
关键词 热流 地壳 地幔 生热率
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Conodont Biostratigraphy of the Middle Cambrian through Lowermost Ordovician in Hunan, South China 被引量:29
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作者 DONGXiping JohnE.REPETSKI StigM.BERGSTR(OE)M 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2004年第6期1185-1206,共22页
Since 1985, samples with a total weight of more than 14,000 kg, mainly from three key sections in western and northwestern Hunan, South China, have been processed for conodonts. In strata older than the late Late Camb... Since 1985, samples with a total weight of more than 14,000 kg, mainly from three key sections in western and northwestern Hunan, South China, have been processed for conodonts. In strata older than the late Late Cambrian paraconodonts have proved useful for stratigraphic subdivision and correlation. Thirteen conodont zones are proposed in the Middle Cambrian through lowermost Ordovician. The correlation between these zones and those of North China, western U. S.A., western Newfoundland, Canada, and Iran is discussed. In ascending order, these 13 zones are as follows: The Gapparodus bisulcatus-Westergaardodina brevidens Zone, Shandongodus priscus-Hunanognathus tricuspidatus Zone, Westergaardodina quadrata Zone, Westergaardodina matsushitai-W. grandidens Zone, Westergaardodina lui-W. am Zone, Westergaardodina cf. calix-Prooneotodus rotundatus Zone, Proconodontus tenuiserratus Zone, Proconodontus Zone, Eoconodontus Zone, Cordylodus proavus Zone, Cordylodus intermedius Zone, Cordylodus lindstromi Zone, and Cordylodus angulatus Zone (lower part). The Westergaardodina lui-W. ani and Westergaardodina cf. calix-Prooneotodus rotundatus Zones replace the Westergaardodina proligula and Westergaardodina cf. behrae-Prooneotodus rotundatus Zones, respectively, in the lowermost Upper Cambrian. Two new species (Westergaardodina Iui and Westergaardodina ani) and one conditionally identified species (Westergaardodina cf. calix) are described. 展开更多
关键词 conodont zonation Middle and Upper Cambrian lowermost Ordovician HUNAN South China.
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Episodes of Cenozoic Gold Mineralization on the Eastern Margin of the Qinghai-Tibet Plateau:40Ar/39Ar Dating and Implication for Geodynamic Events 被引量:5
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作者 WANGDenghong MAOJingwen +4 位作者 YANShenghao YANGJianmin XUJue CHENYuchuan XUEChunji 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2005年第2期233-253,共21页
A lot of new gold deposits have been found on the eastern margin of the Qinghai-Tibet Plateau during the past two decades. Among them, three main types of gold deposits have been recognized, including quartz-vein-type... A lot of new gold deposits have been found on the eastern margin of the Qinghai-Tibet Plateau during the past two decades. Among them, three main types of gold deposits have been recognized, including quartz-vein-type, shear- zone-type and porphyry-type. The former two types of gold deposits are mainly hosted within metamorphic rocks, while the latter is related to Cenozoic magmatism. Although all of these gold deposits are believed to have been formed during the uplift process of the Qinghai-Tibet Plateau in the Cenozoic era (Wang et al., 2002b), precise isotopic age constraints have still been lacking until quite recently. This paper presents new 40Ar/39Ar data of some gold deposits on the eastern margin of the Qinghai-Tibet Plateau, which indicate that gold mineralization in the region occurred in response to the episodic stages of the orogenies. Recently obtained 40Ar/39Ar data on quartz and feldspars from several gold deposits, such as the Sandiao deposit, the Baijintaizi deposit, the Pusagang deposits, provide new constraints on gold mineralization on the eastern margin of the Qinghai-Tibet Plateau. Geochronological studies of gold deposits along the Daduhe River indicate that there are three stages of gold mineralization. The early two stages occurred as early as 65.1 Ma in the Shuibaiyang deposit and 58.95 Ma in the Ruoji deposit, while the latter stage occurred as late as 25.35 Ma in Baijintaizi and 24.70 Ma in Sandiao. Isotopic dating of three plagioclases from the Beiya deposit, Zhifanggou deposit and Luobodi deposit and a K-feldspar from the Jinchangqing deposit in Yunnan Province indicates that these deposits were formed at two stages. The Zhifanggou and Jinchangqing deposits have early stage records as old as 58.82 Ma in Zhifanggou and 55.49 Ma in Jinchangqing, but all of the above four deposits in Yunnan have late stage records of 23.18 Ma in Jinchangqing, 24.54 Ma in Zhifanggou, 24.60 Ma in Luobodi and 24.56 Ma in Hongnitang. The above results suggest that the gold deposits on the eastern margin of the Qinghai-Tibet Plateau were formed concentratedly at two main episodes, i.e. the end of the Paleocene (about 58 Ma) and the boundary between the Paleogene and the Neogene (about 25 Ma). The later episode appears to be looks like more important and was coupled with the Sichuan movement, which was extensively activated at that period. The beginning of the Cenozoic Era (about 65 Ma) might be another episode of gold mineralization, but only one deposit (Shuibaiyang) in this study has been proved to have been be formed at this stage and might be earlier than the initial collision between the Indian Plate and the Eurasia Plate. In view of geology, the above three episodes of gold mineralization are associated with three events of tectonic- magmatism and/or fluid events. Even though the gold deposits (for example, the Shuibaiyang deposit, Ruoji deposit and Pusagang deposit) were formed at different episodes, all of them are genetically related to tectonic movements in large- scale shear zones. It looks like theat tectonic events (including large-scale strike-slip) between Paleogene and Neogene had a wide influence upon gold mineralization, with new deposits formed and old deposits enriched or superimposed to be a higher grade by new stage of mineralization. The above data suggest that gold deposits were not only concentrated in some areas, but also formed mainly at different boundaries of geological times, indicating that there existed some peak stages of gold mineralization (metallogenic episodes), and that the gold deposits were formed mainly by episodic mineralization. 展开更多
关键词 Southwestern China eastern margin of the Qinghai-Tibet Plateau gold deposit metallogenic episodes Sichuan Yunnan the Himalayas CENOZOIC
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The GSSP of the Second (Upper) Stage of the Lower Ordovician Series: Diabasbrottet at Hunneberg, Province of Vaeistergoetland, Southwestern Sweden 被引量:14
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作者 StigM.Bergstroem AnitaLoefgren JoergMaletz 《Episodes》 SCIE 2004年第4期265-272,共8页
Diabasbrottet, selected by the International Subcommisson on Ordovician Stratigraphy and in 2002 ratified by the International Commission on Stratigraphy as the GSSP of the Second (Upper) Stage of the Lower Ordovician... Diabasbrottet, selected by the International Subcommisson on Ordovician Stratigraphy and in 2002 ratified by the International Commission on Stratigraphy as the GSSP of the Second (Upper) Stage of the Lower Ordovician, is located on the Hunneberg Mountain in southwestern Sweden. The stratigraphic succession represents an outer shelf environment near the Baltic Shield margin. The shale-dominated, biostratigraphically complete, richly fossiliferous boundary interval is completely exposed in a disused quarry. The GSSP is in the lower TФyen Shale 2.1 m above the top of the Cambrian and is marked by the first appearance of the graptolite Tetragraptus approximatus Nicholson. The boundary interval contains a diverse graptolite fauna and biostratigraphically diagnostic conodonts and trilobites that make it possible to define the boundary in terms of zone schemes based on these groups. In this respect, the Diabasbrottet and nearby sections are unique in the world among described localities having this boundary interval. Based on the appearance of T. approximatus, the base of the Second Stage can be identified in many graptolitiferous successions round the world but this level is currently more difficult to recognize precisely in some carbonate sequences outside Baltoscandia. We propose the Second Stage be called the Floan Stage. It is named for the Village of Flo, which is situated about 5 km southeast of the GSSP. 展开更多
关键词 GSSP 奥陶纪 Hunneberg山脉 瑞典南部 大陆架 笔石 脊椎动物化石
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Quaternary: status, rank, definition, survival 被引量:3
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作者 Marie-PierreAubry WilliamA.Berggren +3 位作者 JohnVanCouvering BrianMcGowran BradPillans FritsHilgen 《Episodes》 SCIE 2005年第2期118-120,共3页
The long controversy over the term ‘Quaternary' as a chronostratigraphic unit may be reaching an apotheosis, judging from recent papers (Pillans and Naish, 2004; Gibbard et al., 2005; and referencest herein). The... The long controversy over the term ‘Quaternary' as a chronostratigraphic unit may be reaching an apotheosis, judging from recent papers (Pillans and Naish, 2004; Gibbard et al., 2005; and referencest herein). The debate is no longer centered on whether there should be a place in the geological time scale for a unit termed ‘Quaternary'-despite its dubious past, it cannot be denied that a large body of earth-historical research is strongly identified with this term. The challenge now concerns an appropriate rank and definition of Quaternary with regard to other chronostratigraphic units. Several options have been proposed (Pillans and Naish, 2004), and Gibbard et al. (2005) encourage a debate on these before decision is reached. In this brief note, we describe an arrangement not previously considered that seems advantageous. It is instructive, however, to first review the Pleistocene Series and Neogene System, the two units that are directly affected by introduction of the Quaternary into the chronostratigraphic hierarchy. 展开更多
关键词 第四纪冰川 地形特征 沉积作用 识别方法
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Optimal Parameter and Uncertainty Estimation of a Land Surface Model: Sensitivity to Parameter Ranges and Model Complexities 被引量:2
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作者 YoulongXIA Zong-LiangYANG +1 位作者 PaulL.STOFFA MrinalK.SEN 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2005年第1期142-157,共16页
Most previous land-surface model calibration studies have defined globalranges for their parameters to search for optimal parameter sets. Little work has been conducted tostudy the impacts of realistic versus global r... Most previous land-surface model calibration studies have defined globalranges for their parameters to search for optimal parameter sets. Little work has been conducted tostudy the impacts of realistic versus global ranges as well as model complexities on the calibrationand uncertainty estimates. The primary purpose of this paper is to investigate these impacts byemploying Bayesian Stochastic Inversion (BSI) to the Chameleon Surface Model (CHASM). The CHASM wasdesigned to explore the general aspects of land-surface energy balance representation within acommon modeling framework that can be run from a simple energy balance formulation to a complexmosaic type structure. The BSI is an uncertainty estimation technique based on Bayes theorem,importance sampling, and very fast simulated annealing. The model forcing data and surface flux datawere collected at seven sites representing a wide range of climate and vegetation conditions. Foreach site, four experiments were performed with simple and complex CHASM formulations as well asrealistic and global parameter ranges. Twenty eight experiments were conducted and 50 000 parametersets were used for each run. The results show that the use of global and realistic ranges givessimilar simulations for both modes for most sites, but the global ranges tend to produce someunreasonable optimal parameter values. Comparison of simple and complex modes shows that the simplemode has more parameters with unreasonable optimal values. Use of parameter ranges and modelcomplexities have significant impacts on frequency distribution of parameters, marginal posteriorprobability density functions, and estimates of uncertainty of simulated sensible and latent heatfluxes. Comparison between model complexity and parameter ranges shows that the former has moresignificant impacts on parameter and uncertainty estimations. 展开更多
关键词 optimal parameters uncertainty estimation CHASM model bayesian stochasticinversion parameter ranges model complexities
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Topography, exhumation, and drainage network evolution of the Apennines 被引量:2
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作者 CarloBartolini NicolaD‘Agostino FrancescoDramis 《Episodes》 SCIE 2003年第3期212-216,共5页
The present-day topography of the Italian peninsula results from the interactions between crustal-mantle and surface processes occurring since the Late Miocene. Analysis of exhumation and cooling of crustal rocks, ... The present-day topography of the Italian peninsula results from the interactions between crustal-mantle and surface processes occurring since the Late Miocene. Analysis of exhumation and cooling of crustal rocks, together with Quaternary drainage evolution,helps to unravel the tectonic-morphologic evolution of the Apennines by distinguishing end-member models,and hence describing the orogenic belt evolution. The pattern of regional topography, erosional history and present-day distribution of active deformation suggests that the eastward migrating extensional-compressional paired deformation belts may still control the topogra-phy of the northern Apennines, albeit at slower rates than in the past. Conversely, Quaternary drainage evo-lution in the central and southern Apennines suggests that the topography of these regions underwent a Quaternary regional arching, which is only partly con-sistent with the persisting migration of the compres-sional-extensional pair. 展开更多
关键词 地形学 排水网络 亚平宁山脉 意大利 成因 地质特征 剥蚀作用
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Interdiffusion of Na, K, and Ca Between Granitic Melts and NaCl Liquid
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作者 柏天宝 A.F.KOSTERVANGROOS 《Chinese Journal Of Geochemistry》 EI CAS 1996年第2期129-137,共9页
This study is aimed at determining the diffusion coeffcient of net-work modifiers(mainly Na, K, and Ca) in a two-phase melt-NaCl system, in which the melts are granitic andthe system is NaCl-rich in composition. The... This study is aimed at determining the diffusion coeffcient of net-work modifiers(mainly Na, K, and Ca) in a two-phase melt-NaCl system, in which the melts are granitic andthe system is NaCl-rich in composition. The diffusion coefficients of Na, K, and Ca were measured at the temperatures of 750 -1400℃, pressures of 0. 001×108 - 2×108 Pa, and initialH2O contents of O wt% - 6. 9 wt% in the granitic melts. The diffusion coefficients of Fe andMg were difficuIt to resolve. In all experiments a NaCl melt was present as well. In the absence of H2O, the diffusion of net-work modifiers folows an Arrhanious equation at 1 ×105 Pa:lgDCa= - 3. 88 - 5140/ T, lgDK = - 3. 79 - 4040/ T, and lgDNa=- 4.99 - 3350/ T,where D is in cm2/s and T is in K. The diffusion coefficients of Ca, Na, K, and Fe increasenon-linearly with increasing H2O cOntent in the melt. The presence of about 2 wt% H2O inthe melt will lead to a dramatical increase in diffusivity, but higher H2O content has only a minor effect. This change is probably the result of a change in the melt structure when H2O ispresent. The diffusion coefficients measured in this study are significantly different from thosein previous woks. This may be understood in terms of the "transient two-liquid equilibrium"theory. Element interdiffusion dapends not only on its concentration, but also on its activity coefficient gradient, which is reflected by the distribution coefficient, of the two contactingmelts. 展开更多
关键词 岩浆 氯化钠溶液 互相扩散 硅酸盐岩浆
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西藏南部康马穹隆的构造及其演化
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作者 JeffreyLee WillimS.Dinklage 《西藏地质》 2002年第2期55-63,共9页
基于详细地质填图,以及构造,岩石和热年代学研究,提出了一个新的西藏南部康巴穹隆的成因模式。康马地区第一期变形为南北方向的缩短,这一变形导致了康马穹隆地区的地壳增厚,同时伴随着一次热平衡以及峰期变质作用。第二期变形为水... 基于详细地质填图,以及构造,岩石和热年代学研究,提出了一个新的西藏南部康巴穹隆的成因模式。康马地区第一期变形为南北方向的缩短,这一变形导致了康马穹隆地区的地壳增厚,同时伴随着一次热平衡以及峰期变质作用。第二期变形为水平方向的伸展和垂直方向的减薄。之后的变形为穹隆作用和岩体剥露,西藏南部的拆离系与康、马穹隆的形成是同期的,伴随着上盘岩层的收缩变形。沿西藏南部拆离系的正滑作用同时发生。显示在中新世西藏南部同时有伸展和收缩运动。 展开更多
关键词 西藏 康马穹隆 构造演化 岩石 热年代学 变质作用
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Microparticle record in the Guliya ice core and its comparison with polar records since the last interglacial 被引量:12
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作者 WUGuangjian YAOTandong +1 位作者 L.G.Thompson LIZhongqin 《Chinese Science Bulletin》 SCIE EI CAS 2004年第6期607-611,共5页
Based on the study of oxygen isotope and mi-croparticle in the Guliya ice core, atmospheric dust and en-vironmental changes in the northwest Tibetan Plateau since the last interglacial were revealed. The microparticle... Based on the study of oxygen isotope and mi-croparticle in the Guliya ice core, atmospheric dust and en-vironmental changes in the northwest Tibetan Plateau since the last interglacial were revealed. The microparticle record indicates that low dust load on the Plateau in the interglacial. Particle concentration increased rapidly when the climate turned into the last glacial and reached the maximum during the MIS 4. In the Last Glacial Maximum, however, the en-hancement of microparticle concentration was slight, differ-ing to those in the Antarctic and Greenland. On the orbital timescale, both the temperature on the Tibetan Plateau and summer solar insolation in the Northern Hemisphere had their impact on the microparticle record, but the difference in phase and amplitude also existed. Though having the same dust source, microparticle records in the ice cores on the Tibetan Plateau and the Greenland seem to have different significance. 展开更多
关键词 微粒子记录 Guliya冰核 极性记录 末期间冰期 西藏高原 大气灰尘 全球气候
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