Abstract:

The key to the question about fault gouge dating by TL technique is whether the temperature and pressure effect caused by faulting can lead the origional TL to“zoro”for some minerals.For this purpose,we have made the simulated experiments under different temperature,pressureand strain rate which can lead TL intensity of quartz in fault zone to decrease.The results showthat the frictional heating by dislocation of fault walls during faulting is a main factor leading thequartz TL to decrease on the fault plane and that increment of temperature is closely related withthe value of shear stress,gouge thickness and displacements,and it is confirmed by the measurements of fault gouge on the plane.According to above reseach,the time of activity has been dated along F₇ fault at Xiaowan,Yunnan province.

Key words: TL annealing, Frctional heating, Thickness of fault gouge, Displacement, Shear stress

摘要：

断层物质TL测年的关键,是断裂运动产生的温压效应能否使断裂带内某些矿物原贮存的TL能量完全释放而“归零”。为此,进行了不同条件的高温、高压和位移速率变化等的模拟断裂运动的实验。结果表明,断裂运动产生的摩擦增温是使断层面上矿物TL强度减弱的主要因素。讨论了摩擦增温值与断裂运动时剪应力大小、断层泥厚度和断层位移间的关系,并得到了野外断层面上实际测试的证实。据此研究成果,还对小湾坝区F₇断裂的活动时代进行了测定。

关键词: TL退火, 摩擦增温, 断层泥厚度, 位移距离, 剪应力