断层粘滑摩擦增温的理论分析及其对TL,ESR测龄的意义  

FRICTIONAL HEATING BY STICK SLIP AND ITS SIGNIFICANCE FOR TL, ESR DATING

作　　者：李力刚[1] 黄培华[1] 傅容珊[1] 黄建华[1] 徐耀民[1] 

机构地区：[1]中国科学技术大学,合肥230026

出　　处：《地震地质》1999年第4期387-396,共10页Seismology and Geology

基　　金：国家自然科学基金!(49774233)

摘　　要：采用断层位错模式,考虑了具有一定宽度的断层在其粘滑过程中,断层摩擦应力和滑动速度随粘滑过程的变化情况,由此计算了粘滑所产生的摩擦增温,并将结果与不考虑摩擦应力变化、不考虑滑动速度变化或忽略断层宽度时的情况作了比较。结果表明:断层滑动时,摩擦应力和滑动速度随时间的改变及断层的宽度将对断层摩擦增温产生较大影响。由于岩石中孔隙和孔隙流体的存在,摩擦应力在断层粘滑过程中有较大变化。取断层滑动速度为Brune 震源时间函数形式,考虑摩擦应力的变化及一定的断层宽度,计算得到的摩擦增温值较以往的计算结果偏小。这个结论对测定断层活动年代的热释光(TL)和电子自旋共振(ESR) 法具有一定的理论指导意义。It is not appropriate to assume constant frictional stress and constant slip velocity for calculating temperature rise on fault during stick slip. Neither could the fault thickness be simply neglected. In most cases, frictional stress depends on rock and interstitial fluid properties. Five models of frictional heating are considered in this paper for various fault thickness, frictional stress and slip velocity which vary with time. The result shows that temperature rise is lower than those calculated by assuming constant frictional stress, constant slip velocity or zero fault thickness. This conclusion will remind scientists to pay attention to the result precise of TL and ESR dating.

关 键 词：粘滞滑动 热释光法 ESR测龄 摩擦增温 断层 

分 类 号：P542.3[天文地球—构造地质学] P597.3[天文地球—地质学]