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121.
南秦岭凤凰山地区元古代构造基底特征 总被引:5,自引:0,他引:5
依据在原划武当岩群中获得的 1 6 86± 4 5Ma (锆石U -Pb)同位素测年资料 ,结合岩石学、岩石地球化学及区域地层对比 ,从中解体出姚坪岩组。通过岩石学、岩石地球化学、构造特征、变质变形特征研究及形成环境探讨认为 :南秦岭凤凰山元古代武当岩群 (包括姚坪岩组、杨坪岩组 )变质火山岩系为古—中元古代时期多岛洋构造环境过渡基底建造 ;耀岭河岩组浅变质火山岩为本区Rodina事件的产物。该成果对南秦岭构造基底的组成、发展、演化研究具有重要意义。 相似文献
122.
川南区域构造变形及应力场遥感图像定量解析 总被引:13,自引:0,他引:13
采用区域构造变形及应力场遥感图像分层解析法,利用遥感TM图像对研究区宏观构造及有关的横张大节理系统进行详细解译,结合物探资料并应用力学方法对区域构造变形场和应力场进行了计算与分析,建立了该区构造变形场和应力场的三维彩色定量解析模式图,通过综合分析研究,对该区构造组合的空间格局及其控矿(油气)规律进行了探讨。 相似文献
123.
远场和超远场前兆的模拟实验研究 总被引:7,自引:0,他引:7
在岩石试件、传压块体(包括岩石和钢块)和压机架上布设应变观测点,观测研究它们在岩石试样破裂孕育过程中的变化特征。结果发现,岩样临破坏前除岩样上各个测点都出现异常变化外,同时较远处的测力元件、传压块体和压机架上的应变也出现了突变或扰动前兆异常。岩石试样外部测点的应变特征变化在极临近主破裂时才有反映。而岩样上的测点除极临近主破裂时有突变和扰动外在离主破裂较早时已有反映。岩石试样外的测点距岩样约25-90cm,约为破裂尺度的3-10(多)倍。这表明在孕震区以外很远的地方都可能出现前兆异常。并初步探讨了形成远场前兆的原因。 相似文献
124.
利用区域化探归面(水系沉积物测量)资料,使用区域浓度克拉克值及变化系数两个参数,对福建省32种元素的资源潜力进行了排序,认为在目前国家的导向矿种中,福建省的资源潜力依次为锌-银-铅-锡-金-铜-钼。同时根据谢学锦院士提出的地球化学块体学块体的理论和方法,预测了政和Au地球化学块体、龙岩中甲Cu地球化学块体、大田Pb地球化学块体的资源潜力,分别为金430吨、铜625万吨、铅408万吨。初步探讨了成矿系统的元素分带及地球化学模式研究的意义和方法,认为这项研究对上述地区的打矿突破具有重要作用。 相似文献
125.
Tectonics of Precambrian basement of the Tarim craton 总被引:4,自引:0,他引:4
The Altyn Tagh Mountain is the main area where the Precambrian basements of Tarim craton are exposed. There are two ophiolitic
belts in Altyn Tagh: one belt is exposed in the northern margin of Altyn Tagh whose formation age is about (829±60) Ma, the
other is situated along the southern margin of Altyn Tagh and has a formation age of about (1449±270) Ma. This paper proposes
a simple tectonic model for the Precambrian basement of Tarim craton established from ophiolites in Altyn Tagh area. The south
Tarim block had amalgamated with Qaidam block during about 1400-1500 Ma along the present Altyn fault, while the south Tarim-Qaidam
united block was still separated from the north Tarim block by an ocean. The united block of south Tarim and Qaidam collided
with north Tarim block along the zone of high positive anomaly of central Tarim, Hongliugou and Lapeiquan in about 800 Ma.
So since the Sinian (beginning at 800 Ma) there has been an integrated basement for Tarim craton. 相似文献
126.
本文介绍了用计算机辅助设计软件AUTOCAD与三维动画软件3DMAX来绘制峨嵋山地区块体图的方法,以此为例子讲述了将地形图改画面三维图的具体操作步骤,并进一步论述了用计算机绘制块体图的方法有着广泛的应用及其实用价值。 相似文献
127.
The sliding block theory was proposed by Newmark for determining the permanent displacement of embankments and dams under earthquake loading. This paper highlights recent applications of sliding block theory to different geotechnical structures. The equations to determine seismic factor of safety, yield acceleration and permanent displacement are given for rock block, soil slope, landfill cover, geosynthetic-reinforced soil retaining wall, and composite breakwater. The presented equations for seismic stability degenerate to that of static stability in the absence of earthquake. The permanent displacement for various structures can be obtained from that of a horizontal sliding block through a correction factor. A simplified procedure is included for the permanent displacement under vertical acceleration. The sliding block approach is rational for design under high seismic load. 相似文献
128.
Model of rigid and elastic-plastic motion in intraplate blocks and strain status of principal blocks in Chinese mainland 总被引:5,自引:1,他引:5
Introduction The Chinese mainland is located in the southeastern part of Eurasia plate and encircled by India, Eurasia, Pacific and Philippine Sea plates. It is one of areas with the strongest tectonic de-formation, especially Qingzang (QinghaiXizang) plateau and NS tectonic zone where the tec-tonic activity is more intensive and intricate. The main part of tectonic activity of Chinese mainland includes a series of tectonic zones and active blocks divided by them. Therefore, the research… 相似文献
129.
Post-earthquake investigation on several geosynthetic-reinforced soil retaining walls and slopes during the Ji-Ji earthquake of Taiwan 总被引:1,自引:0,他引:1
Hoe I. Ling Dov Leshchinsky Nelson N. S. Chou 《Soil Dynamics and Earthquake Engineering》2001,21(4):3087
This paper gives an overview on the application of geosynthetic-reinforced soil structures in Taiwan. Taiwan has an unique topography and geotechnical conditions that rendered a less conservative and more challenging design compared to that of North America, Europe and Japan. The Ji-Ji (Chi-Chi) earthquake of 1999 gave an opportunity to examine the behavior of reinforced soil structures. The performance of several modular-block reinforced soil retaining walls and reinforced slopes at the vicinity of the fault was evaluated. Reinforced structures performed better than unreinforced soil retaining walls. The failure cases were highlighted and the cause of failure was identified. The lack of seismic design consideration could be a major cause of failure. The compound failure mode, the inertia force of the blocks, and the connection stiffness and strength relative to the large dynamic earth pressure, were among major items that would warrant further design consideration. 相似文献
130.
V. Pereyra 《Pure and Applied Geophysics》1996,148(3-4):345-386
We describe an integrated forward and inverse three-dimensional modeling system that can deal with complex geological structures. The system has been designed to handle large-scale problems by using a distributed approach. It uses seismic ray tracing for forward simulation, time-to-depth mapping, and nonlinear travel-time inversion.A novel decomposition method is our tool to attack large-scale problems in a parallel approach. The system is fully implemented and we demonstrate its performance with synthetic examples.This research was partially supported by the National Science Foundation under SBIR Grant III-9300992. 相似文献