中国各省区对外开放度比较研究   总被引：16，自引：1，他引：15  

谢守红 《地理科学进展》2003,22(3):296-303

改革开放以来,中国对外开放水平不断提高,但各地区之间差异显著。关于我国对外开放度的测定已引起学术界的重视,但对经济开放度的区域差异研究很少。文章采用1990年和2000年的统计资料对中国各省区对外开放度进行测定和比较分析,结果表明1990年以来各省区对外开放度普遍有了明显的提高,对外开放度的排序有了一些变化,但总体格局没有改变。各省区之间对外开放度存在巨大差异,不仅东、中、西三大地带之间差异显著,而且区域内部也存在明显差异。最后,根据对外开放度的时空差异特征对各省区进行分类,并得出若干结论和启示。  相似文献   

Incomplete high P–T metamorphic transitions within the Kvamsøy pyroxenite complex, west Norway: a case study of disequilibrium     

MAI BRITT E. MØRK 《Journal of Metamorphic Geology》1985,3(3):245-264

Abstract The Kvamsøy pyroxenite complex consists of olivine websterite, olivine gabbro and leucogabbro-norite which have been subjected to regional high P-T (HPT) metamorphism. The metamorphism has resulted in a range of disequilibrium textures with the development of coronas and pseudomorphism of the igneous phases. Reactions between felsic and mafic mineral domains have been controlled by variable and selective diffusion of elements, resulting in a variety of local plagioclase-breakdown reactions and in significant compositional variations for the product garnet. Restricted diffusion favours transient reaction stages with garnet ± spinel ± corundum ± zoisite after calcic plagioclase in olivine gabbro and olivine websterite and garnet ± spinel ± kyanite ± quartz + sodic plagioclase in leucogabbro-norite. Complete HPT reaction has produced garnet pyroxenite which consists of garnet + diopside + hornblende + zoisite in gabbroic rocks, while amphibolitization continued during the cooling and uplift history. Grt + Ky + Pl + Qtz geobarometry suggests pressures in the range 13-16 kbar for T = 750°C, comparable with the regional eclogite-forming metamorphism.  相似文献   

Constraints on element mobility associated with the conversion of granulite to eclogite along fractures in an anorthositic complex on Holsnøy, Norway   总被引：1，自引：0，他引：1  

K. M. ROCKOW  L. A. HASKIN  B. L. JOLLIFF  & D. M. FOUNTAIN 《Journal of Metamorphic Geology》1997,15(3):401-418

On Holsnøy, an island off the coast of Western Norway, an anorthositic complex metamorphosed to granulite facies was partially overprinted by a later eclogite facies metamorphism. Eclogite facies rocks (containing omphacite, garnet, kyanite and hydrous phases such as mica and zoisite) occur in shear zones of various scales and adjacent to veins. Previous studies of shear zones on Holsnøy reported evidence for substantial element mobility (Jamtveit et al ., 1990; Mattey et al ., 1994). In this work, we compare chemical compositions of granulite and its undeformed eclogitized equivalent adjacent to veins in locations where a single band of granulite can be traced and sampled as it approaches the vein. This tracing is crucial because the pre-granulite rocks cover a substantial compositional range, indicative of a petrologically variable protolith consisting of anorthosite, gabbro and jotunite. We analysed multiple core samples collected across nine separate granulite-eclogite transition zones located at veins in anorthositic, jotunitic and gabbroic protoliths for major and trace elements. For each transition, no compositional difference between the average granulite and average eclogite composition was found at the 90% confidence level except for LOI (loss on ignition), which was consistently significantly higher in the eclogite samples. Although not significant at the 90% confidence level for any single traverse, the average eclogite concentrations of SiO₂ , Na₂O, Cs, As and Br exceed the average granulite concentrations for eight or all nine of the traverses. For most traverses, statistical analysis of the data limits any gain of SiO₂ in the eclogites to no more than a few relative per cent. Other than the introduction of volatile substances, presumably an H₂O-rich fluid, eclogitization associated with vein formation was essentially isochemical.  相似文献   

波谱曲线指数化的方法和意义   总被引：2，自引：1，他引：2  

刘建明  陈建平 《地球科学进展》1995,10(2):205-209

地质研究对象的各种波谱曲线和数据包括显示量（由曲线的高低位置反映的总体辐射强度）和质（由曲线内部的起伏结构反映的不同波段辐射强度的内在相互关系）两方面的特征，其总体辐射强度往往因各种观测因素和条件的不同而发生变化，但其曲线结构形式一般不会因此而改变，本文一般性地介绍一种将复杂的原始波谱曲线简简单指数的思路和方法，使各种波谱曲线所反映的物体内在本质特征是以加强突出，同时尽量弱化总体辐射强度这一易变的  相似文献   

Carbon and oxygen isotopes of Maastrichtian–Danian shallow marine carbonates: Yacoraite Formation, northwestern Argentina     

Rosa Marquillas  Ignacio Sabino  Alcides Nobrega Sial  Cecilia del Papa  Valderez Ferreira  Stephen Matthews 《Journal of South American Earth Sciences》2007,23(4):304-320

The Maastrichtian–Danian limestones of the Yacoraite Formation (northwestern Argentina) show carbon and oxygen isotopic values consistent with shallow marine conditions. The members of the formation respond to different sedimentary environments and are characterised by distinctive stable isotopes and geochemistry. The basal Amblayo Member is composed of high-energy dolomitic limestones and limestones with positive isotopic values (+2‰ δ¹³C, +2‰ δ¹⁸O). The top of the member reveals an isotopic shift of δ¹³C (−5‰) and δ¹⁸O (−10‰), probably related to a descent in the sea level. The sandy Güemes Member has isotopically negative (−2‰ δ¹³C, −1‰ δ¹⁸O) limestones, principally controlled by water mixing, decreased organic productivity, and compositional changes in the carbonates. The isotopically lighter limestones are calcitic, with a greater terrigenous contribution and different geochemical composition (high Si–Mn–Fe–Na, low Ca–Mg–Sr). These isotopic and lithological changes relate to the Cretaceous–Palaeogene transition. The Alemanía Member, composed of dolomitic limestones and pelites, represents a return to marine conditions and shows a gradual increase in isotopic values, reaching values similar to those of the Amblayo Member. The Juramento Member, composed of stromatolite limestones, shows isotopic variations that can be correlated with the two well-defined, shallowing-upward sequences of the member.  相似文献   

New constraints on metamorphism in the Rauer Group, Prydz Bay, east Antarctica   总被引：12，自引：0，他引：12  

D. E. Kelsey  R. W. White  R. Powell  C. J. L. Wilson  C. D. Quinn 《Journal of Metamorphic Geology》2003,21(8):739-759

Abstract Granulite facies metapelites of the Mather and Filla Paragneisses within the Rauer Group, east Antarctica, possess markedly different compositions. The metamorphic evolution of the two metapelite types has been interpreted as temporally distinct, with the Rauer Group preserving at least two distinct granulite facies tectonothermal episodes. Calculated P–T pseudosections and orthopyroxene Al content indicate the revised maximum‐preserved P–T conditions within the Mather Paragneiss to lie in the vicinity of 950–975 °C and 10–10.6 kbar, less extreme than previous estimates. The range of possible P–T paths for the Mather Paragneiss consistent with mineral textural relationships and pseudosections contoured for mineral proportion are significantly shallower (dP/dT) than previous estimates. A near‐isothermal decompression P–T path, and extreme peak metamorphic conditions, are not necessary to explain the development of preserved mineral reaction textures. The Filla Paragneiss contains pelitic assemblages less amenable to rigorous quantitative analysis. Nevertheless, possibilities for the shared or otherwise metamorphic evolution of the Mather and Filla Paragneisses may be postulated on the basis of calculated pseudosections in the context of existing geochronology for the Rauer Group and preserved microstructures. A shared evolution, most likely during Pan‐African granulite facies metamorphism, is plausible and consistent with mineral assemblage development, geochronology and microstructures. A revised interpretation of the Rauer Group's preserved metamorphic evolution may warrant the revision of existing tectonic models, applicable also to the remainder of Prydz Bay. More generally, the employed approach may incite a revision of peak P–T and P–T paths in other granulite facies terranes.  相似文献   

磁尾地向传播等离子体团的模拟研究          下载免费PDF全文

杨红昂  金曙平 《地球物理学报》2002,45(5):611-623

卫星观测证实了磁尾等离子体团与亚暴活动的相关性,除了具有北-南双极特征的尾向传播等离子体团外,还发现地向传播等离子体团,它们表现为南-北双极中性片事件和南-北双极瓣区讯号. 资料分析表明:南-北双极讯号的出现几率远低于北-南双极讯号,并且南-北双极事件主要发生于行星际磁场北向和地磁宁静条件,它们往往与小的孤立的地磁亚暴相关. 本文根据地磁宁静时期(IMF Bz北向且By≥Bz)越尾电场Ey分量的分布特点,对地向传播等离子体团作模拟研究. 两类算例的数值结果展示了通量绳磁结构及具有复杂闭合磁力线位形的等离子体团的基本特征,上述特征与尾向传播的等离子体团类似,与IMP 8卫星关于地向传播南-北中性片事件的观测特征大致相符. 数值结果还展示了与Schindler示意图相类似的磁力线拓扑位形,在一定程度上为南-北事件出现几率低作出了解释;并且揭示了磁尾中性片内越尾磁场分量By对磁重联发展的抑制作用. 本文的模拟研究说明:无论磁尾处于活动时期(IMF Bz为南向),还是宁静时期(IMF Bz为北向且By≥Bz),磁场重联均是磁尾等离子体加速和加热的通用机制.  相似文献   

西藏班公湖-怒江结合带北缘多龙地区侏罗纪 增生杂岩的特征及意义   总被引：25，自引：1，他引：24  

李光明  段志明  刘波  张晖  董随亮  张丽 《地质通报》2003,22(1):1256-1260

提出遥感图像地质解译三维可视化及影像动态分析新方法,综合利用3S技术,遥感图像数字处理技术,虚拟现实和全数字摄影测量等高科技,通过遥感图像的正射影像处理,多类型遥感图像数据融合,高精度DEM生成和影像复合等工序,按照一定比例尺和飞行路线生成测区的虚拟三维影像动画系列图,以解决高原区数字区调工作者面临的实际问题,弥补其不足。  相似文献   

山东费县地质灾害易发程度分区评价     

朱伟 《山东地质》2014,(1):41-44

通过调查,认为费县地质灾害主要为滑坡、崩塌、泥石流,其发育与地形地貌、地层岩性、地质构造和人类工程活动、大气降水关系密切。依据地质灾害发育现状和规律、致灾因子,利用 MapGIS空间分析功能和 Microsoft Ex-cel数据计算功能对其进行叠加,获得各评价单元的地质灾害综合危险性指数,将费县地质灾害易发程度分为高易发区、中易发区、低易发区、不易发区4个区,并进行了分区评价。为当地国土资源部门的地质灾害防治工作提供科学的理论依据。  相似文献   

日照市西赵村崩塌地质灾害评估及治理方法     

秦泗伟  ;王光栋 《山东地质》2014,(12):51-53

目前,日照市因废弃矿山引发的地质灾害主要表现在崩塌、滑坡等方面,对废弃矿山进行地质灾害预测并根据实际情况制定治理方案,不但能有效避免因地质灾害造成的损失,又能绿化生态环境,消除视觉污染。通过对日照市岚山区巨峰镇西赵村崩塌体的基本特征及现状进行影响评估,并就西赵村崩塌地质灾害的治理方案进行了初步分析探讨,为日照市因废弃矿山普遍引发崩塌地质灾害的防治提供了理论基础资料。  相似文献