大别高压和超高压榴辉岩中绿辉石的透射电镜研究   总被引：1，自引：0，他引：1  

吴秀玲  韩郁菁  孟大维  杨巍然  李斗星 《矿物岩石地球化学通报》1998,(4)

近年来有关大别山超高压变质岩的研究取得了重要进展。但对榴辉岩的显微和超微构造的研究仍然不足。榴辉岩主要由石榴石和绿辉石组成,其中石榴石基本上相当于刚性体,除非在很高温条件下石榴石才发生韧性变形［１～４］。因此,笔者对高压和超高压榴辉岩中的绿辉石进行了...  相似文献   

Analysis of oil lens removal by extraction through a seepage face     

M.I.J. van Dijke  S.E.A.T.M. van der Zee 《Computational Geosciences》1998,2(1):47-72

Removal of LNAPL (oil) from an aquifer is described using a multiphase flow model. At the well boundary seepage face conditions are imposed. These conditions are implemented in a numerical model and withdrawal in a twodimensional domain is simulated for two different geometries of the oil lens and for varied values of the physical parameters. Assuming vertical equilibrium, the oil flow equation is reduced by vertical integration. The well boundary condition is approximated by imposing zero oil lens thickness. Similarity solutions of the reduced equations for the two geometries show good agreement with the numerical results in most cases.  相似文献   

苏北榴辉岩成因类型及其形成条件   总被引：5，自引：0，他引：5  

樊金涛  程振香 《岩石矿物学杂志》1998,(2)

苏北榴辉岩至少存在高压壳源型（Ｈ型）、超高压壳源型（Ｕ型）和幔源型（Ｍ型）三类。其中Ｈ型榴辉岩的石榴石为铁铝榴石,具正环带结构,单斜辉石属低硬玉绿辉石,主要形成于晋宁期低温高压变质条件下的下地壳;Ｕ型榴辉岩含微粒金刚石（？）、柯石英及其假象等,发育放射状胀裂结构和正、反环带结构,石榴石为钙铝榴石,单斜辉石属高硬玉绿辉石,主要形成于印支期高温超高压变质条件下的上地幔;Ｍ型榴辉岩的石榴石属镁铝榴石,形成于晋宁期高温超高压条件下的岩石圈与软流圈交界附近。  相似文献   

苏北榴辉岩成因型及其形成条件   总被引：4，自引：0，他引：4  

樊金涛  程振香 《岩石矿物学杂志》1998,17(2):118-127

苏北榴辉岩至少存在高度压壳源型（Ｈ型）、超高压壳源型（Ｕ型）和幔源型（Ｍ型）三类。其中Ｈ型榴辉岩的石榴石为铁铝榴石,具正环带结构,单斜辉石属低硬玉绿辉石,主要形成于晋宁期低温度高压变质条件下的下地壳;Ｕ型榴辉岩含微粒金刚石（？）、柯石英及其假象等,发育放射状胀裂结构和正、反环带结构、石榴石为钙铝榴石、单斜辉石属高硬玉绿辉石,主要形成于印支期高温超高压变质条件下的上地幔;Ｍ型榴辉岩的石榴石属镁铝榴石  相似文献   

华中榴辉岩域的岩浆型榴辉岩及其形成机制   总被引：5，自引：0，他引：5  

刘国惠  丛日祥 《地质论评》1997,43(4):356-364

中国中部鄂豫皖苏鲁的榴辉岩分布面积约达５００００ｋｍ＾２，构成地球上一个罕见的宏大的榴辉岩域。榴辉岩的主要围岩是长曲质片麻岩，它与榴辉岩不是相同高压变质作用的产物。  相似文献   

Petrology and Petrogenesis of the Eclogite in Mt.Dabie Area,Central China     

张建珍  杜建国等 《中国地球化学学报》1996,15(3):228-238

The occurrence,mineralogy and geochemistry of eclogites in the Mt.Dabie area show that they were subjected to a high-pressure metamorphism together with the country rocks,but their petrochemistry and REE geochemistry show some difference from those of the country rocks.The geochemical characteristics of the eclogites are similar to those of bot continental tholeiitic basalt and oceanic tholeiitic basalt.The rocks probably subducted to the upper mantle with the Dabie metamorphic complex.When elevated to the surface,they were subjected to different staes of retrogressive metamorphism.  相似文献   

Deep-crustal mineral assemblages and potential for crustal rocks below the Moho in the Scottish Caledonides   总被引：3，自引：0，他引：3  

Andrew Hynes  David B. Snyder 《Geophysical Journal International》1995,123(2):323-339

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三组透镜组成的望远镜物镜系统     

李以赫 《武汉大学学报(信息科学版)》1987,(2)

本文讨论了望远镜采用正或负透镜调焦的准距条件公式,得出它们可以用同一公式表达,并得出伪准距点与主物镜前焦点是焦距为(2e-L),且位于主物镜处的虚拟透镜的共轭点。由此说明了两组透镜组成的望远镜物镜系统后组到分划板的距离一般不够安放补偿器。 文中指出了三组透镜组成的望远镜物镜系统可以解决上述困难,并给出了全部参数的解算方法、程序和算例。这有助于我国目前自动安平水准仪的更新换代。  相似文献   

中国东部沿海基岩海岛地下水资源分布特点——以庙岛群岛为例          下载免费PDF全文

庞忠和 《地质科学》1987,(3):291-299

本文依据对庙岛群岛基岩裂隙水进行的地质构造、水文地质、物探等方面的研究,提出了适用于我国东部沿海基岩海岛的地下淡水蘑菇体新模式。以新构造控水为指导思想,探讨了基岩海岛裂隙水的赋存条件及富集规律,指出了地下水资源开发方向,并且结合生产实际,比较有效地解决了研究区变质岩海岛找淡水难的问题。  相似文献   

Formation Depth of Coesite-Bearing Eclogite, Dabie UHPM Zone, China     

Lü Guxian 《中国地质大学学报(英文版)》2004,15(2):206-215

The plastic deformation of garnet in coesite-bearing eclogite,quartz eclogite and garnet amphibolite of the UHPM complex in Yingshan County in the Dabie Mountains has been studied. The stress generated by the strong tectonic movement was an important component of the total pressure that resulted in the formation of the eclogite in the Dabie UHPM zone. The three-dimensional tectonic principal stresses and additional tectonic stress-induced hydrostatic pressure ［ps=(σ1 σ2 σ3)/3］ are reconstructed according to the differential stress and the strain ratio(α) of the garnet in the minor coesite-bearing eclogite of the Yingshan County. Then the gravity-induced hydrostatic pressure(pg) is calculated following the equation p minus ps,where p is estimated to be 2.8 Gpa based on the quartz-coesite geobarmeter. Therefore,the thickness of the rock column overlying the coesite-bearing eclogite in the Ying-shan County is determined ≥32 km. This estimation,significantly different from ≥100 km,the previous one obtained solely based on the weight/specific weight ratio(W/SW),offers a proper explanation for the puzzle that no tracer of the addition of mantle-derived material has been found in the Dabie UHPM zone during the process of UHPM,although a number of researchers claim that this process took place at the depth of the mantle(≥100 km). It is concluded that attention should be paid to the additional tectonic stress-induced hydrostatic pressure in the study of UHPM zones.  相似文献