郑英龙[1]1990年在《青藏高原岩石圈应力分布特征及其地质意义》文中进行了进一步梳理All of the models formulated beforehand, which attempt to accountfor the crustal shortening, thickening, uplifting and other phenomenaof the Qinghai-Tibet plateau, can chiefly be summarized into threeclasses in terms of dynamical mechanism: (1)Underthrusting andcollision models by compression of the Indian plate. (2)Gravitationaltectonic models by the surface load both top snd bottom ofLithosphere. (3)Two-direction (horizontal and vertical) compressionmodels from the Indian plate and plateau itself. First two classes areonly one-side view, however, the third is comparatively morereasonable. Therefore, author considers the third class as startingpoint to set up the effective model.1. Mathematical principleThe stresses caused by compression below and above can beexpressed as follows; T_(ij.i)=ρg u_(i,j)δ_(3j)-ρg u_(3,j)……(1) T_(ij)=λu_(k,k)δ_(ij+μ) (u_(i,j)+u_(j,i))……(2)Here,ρand g are the original density and acceleration of gravity;u_(ij) and T_(ij) are the displacent and stress tensor of the deforniation.By means of several wavenumber transformation the solutions ofequations (1) and (2) can be expressed as the form of propagatormatrices: W(k,o)=Q_1·Q_2……Q_n·W(k,H)……(3)where W(k,o) and W(k,H) are the stress and displacement matrices ofthe deformation, Qi is Lagrange interpolation matrix of e~(Mi(z-zi)).According to the boundary conditions of the Qinghai-Tibet plateauabout top and bottom surface load, We can obtain the stresses anddisplacements of the deformation.The stresses under the horizontal compression can also be expressedas:σ_(xx)=-E/(1-V~2) Z d~2l/dx~2……(4) where l is the solution of the elastic plate bending equation: D(d~4)／(dx~4)+P(d~2l)／(dx~2)+△ρgl=q_a (x)……(5)where D is the flexural rigidity, P is the horizortal compressionstress, q_a (x) is the Load of the topography at x.As a result, We can obtain the stresses and displacements of thedeformation in terms of the overlapping principle of stresses anddisplacements under the boundary conditions of the Qinghai-Tibetplateau, thereby, the maximum shear stress and fracture stress caneasily be obtained by: T_(xx)=(σ_1-σ_3)／2τ_o=σ_1／2[(f~2+1)~(1／2)-f]-σ_3／2[(f~2+1)~(1／2)+f]Here,σ_1 andσ_2 are the greatest and least principal stresses; fis the coefficient of static friction.Bending under the Quarternary continental glacial sheet can becomputed according to the equation (5), Because of the short time ofthe isostatic adjustment, We look l in (s) as an amount of upliftingafter the glacial sheet began to dispear.2. The distributive characteristics of stresses and theirgelogical meaningAccording to the computation in this paper, author summerize thedistributive characteristics of the stresses of the Qinghai-Tibetplateau into several main points: a. The stress intensity andtheir maintaining depth at the border of the plateau are much largerthan within the plateau, b. The compression stress within theplateau at the top of lithosphere alternates with the tension stress,and at the bottom the stress becomes tensional, c. The divisionalboundary and top surface of the medium appear to be the maximum, Whichare at the side of stronger elastic medium. Within the lower velocitylayers the stresses become minimum, but the larger stresses areaccumulated at the edge of the surrounding layers. These conclusionsare suitable to the horizontal normal stress, the maximun shear stressand fracture stress, d. The horizontal normal stress T_(xx) istensional at S-N direction beneath the Ganga busin. e. Thecompressive stresses from the Indian plate, which are attenuated very rapidly, are smaller than the stresses brought about by gravitation.The geplogical meaning of the distributive stresses in theQinghai-Tibet plateau can be drawn as follows:(1) The distrnbutive characteristics of the stresses of theplateau represent the regularities of the current tectonic movementsand earthquake activities.(2) The N-S trending active tectonic systems represent maximum E-Wtrending tensional stresses and between the two are zone of maximumcompressive stress.(3) The crust in Tibet can be divided into five layers in terms ofthe relationship between stresses and lower velosity zones and theconcentrated depthes of the carthquake distribution.(4) The spreading forces and buoyaucy of the anomalous mantlecaused by compression of Indian plate and gravitation may be mainpoints of the whole uplift Of the plateau. In the late plate collisionthe compression from the Indian plate may be concentrated in south ofthe plateau, and it causes the different uplifting and is a minoruplifting stress. The uplift of himalaya mountain higher than theother part of the plateau has a close relation with the compressionfrom the Indian plate.(5) After the Quarternary continental glacial sheet disappeared,the uplift of the plateau is no more than 700m, which only have atrivial effect on the whole uplift of the plateau.
徐纪人, 赵志新[2]2006年在《中国岩石圈应力场与构造运动区域特征》文中进行了进一步梳理笔者系统分析了1918—2005年间中国大陆及其周缘发生的3130个中、强地震的震源机制解,根据其特征进行了岩石圈应力场构造分区,首次得到区域应力场的压应力轴和张应力轴空间分布的统计数字结果。在此基础上研究了应力场的区域特征、探讨了其动力学来源以及构造运动特征。总体结果表明,中国大陆及其周缘岩石圈应力场和构造运动可以归结为印度洋板块、太平洋板块、菲律宾海板块与欧亚板块之间相对运动,以及大陆板内区域块体之间的相互作用的结果。印度洋板块向欧亚板块的碰撞挤压运动所产生的强烈的挤压应力,控制了喜马拉雅、青藏高原、中国西部乃至延伸到天山及其以北的广大地区。在青藏高原周缘地区和中国西部的大范围内,压应力P轴水平分量方位位于20～40°,形成了近NE方向的挤压应力场。大量逆断层型强震集中发生在青藏高原的南、北和西部周缘地区,以及天山等地区。而多数正断层型地震集中发生在青藏高原中部高海拔的地区,断层位错的水平分量位于近东西方向。表明青藏高原周缘区域发生南北向强烈挤压短缩的同时,中部高海拔地区存在着明显的近东西向的扩张运动。中国东部的华北地区受到太平洋板块向欧亚板块俯冲挤压的同时,又受到从贝加尔湖经过大华北直到琉球海沟的广阔地域里存在着的统一的、方位为170°的引张应力场的控制。华北地区大地震的震源机制解均反映出该区地震的发生大体为NEE向挤压应力和NNW向张应力的共同作用结果。台湾纵谷断层是菲律宾海板块与欧亚板块之间碰撞挤压边界。来自北西向运动的菲律宾海板块构造应力控制了从台湾纵谷、华南块体,直到中国南北地震带南段东部地域的应力场。地震的震源机制结果还表明,将中国大陆分成东、西两部分的中国南北地震带是印度洋板块、菲律宾海板块与太平洋板块在中国大陆内部影响控制范围的分界线。
徐纪人, 赵志新[3]2006年在《青藏高原及其周围地区区域应力场与构造运动特征》文中提出本文系统解析并分析了1931年8月-2005年10月期间青藏高原及其周围发生的905个震级M4．5-8．5地震的震源机制结果,研究了青藏高原岩石圈的区域应力场与构造运动特征。结果表明,来自印度板块的北北东或北东方向的水平挤压应力控制了青藏高原及其周缘地区的岩石圈应力场。从喜马拉雅到贝加尔湖以南包括中国西部的广大范围内,主压应力P轴的水平分量位于近NE-SW方向,形成了一个广域的NE-SW方向的挤压应力场。特别是青藏高原周缘地区,除其东部边缘外,南部的喜马拉雅山前沿以及青藏高原的北部、西部边缘地区所发生的绝大部分地震都属于逆断层型或走滑逆断层型地震,表现出周缘地区的水平挤压应力更为强势。应力场特征充分表明, 印度板块的北上运动,以及它与欧亚板块之间的碰撞,所形成的挤压应力场是青藏高原强烈隆起的直接原因。在青藏高原周缘地区受到强烈挤压应力场控制的同时,有大量正断层型地震集中发生在青藏高原中部海拔4000m以上的地区,其中许多地震是纯正断层型地震。震源机制结果显示,近E-W向或WNW-ESE向的水平扩张应力控制着该区的岩石圈应力场;正断层型地震的断层走向多为南北方向,断层位错矢量的水平分量大体位于近东西方向。这表明青藏高原中部高海拔地区存在着近东西方向的扩张构造运动,且扩张构造运动是该区引张应力场的作用结果。其动力学原因可能与持续隆升的高原自重增大引起的重力崩塌及其周边区域构造应力状况有关。研究青藏高原存在挤压应力场与引张应力场及其构造运动的区域特征,对于认识青藏高原形成、发展的地球动力学机制,有着极其重要的意义。
李起彤[4]1992年在《地震地质学研究新进展和新思考》文中研究表明本文作者提出,地震地质学研究内容应以与地震有关的活动构造为主要研究对象。近4年来,地震地质学研究在多方面取得了重要进展。文章主要对板块运动、岩石圈应力场、断层力学、活动构造、长期地震预测方面的新进展做了概略介绍。最后,根据国际研究动态,结合我国实际情况,对我国地震地质学今后研究重点和方向提出了几点个人思考意见,供有关方面参考。
参考文献：
[1]. 青藏高原岩石圈应力分布特征及其地质意义[D]. 郑英龙. 中国地质科学院. 1990
[2]. 中国岩石圈应力场与构造运动区域特征[J]. 徐纪人, 赵志新. 中国地质. 2006
[3]. 青藏高原及其周围地区区域应力场与构造运动特征[J]. 徐纪人, 赵志新. 中国地质. 2006
[4]. 地震地质学研究新进展和新思考[J]. 李起彤. 国际地震动态. 1992
标签：地质学论文; 地球物理学论文; 岩石圈论文; 构造地震论文; 地震预测论文; 板块运动论文; 地质论文; 地震论文;