内蒙古温都尔庙早古生代板块俯冲带内变形岩石的有限应变测量

THE ESTIMATION OF FINITE STRAINS ON THE DEFORMED ROCKS WITHIN THE WENDUERMIAO EARLY PALAEOZOIC PLATE SUBDUCTION ZONE IN INNER MONGOLIA

内蒙古温都尔庙早古生代板块俯冲带内变形基性熔岩中杏仁体的有限应变测量和电算数据处理取得了较好的一致性,结果表明:反映区域挤压应力场的应变椭球最大缩短(z)轴倾向南南西,中等倾角;呈东西向延展的8—10公里宽的俯冲带内,应变强度由北往南依次递增,x/z 应变轴比从3.015增大到7.233.论证了内蒙古海洋板块俯冲于华北陆台之下的地质事件.本文还论述了以明胶冻为试件进行的模拟试验,获得了应力—应变关系曲线,测算出变形标志体在 xz 面上应变轴比与压应力的理论数值。

The estimation answers to the calculation in finite Strains on amygdaloid in the deformed basic lava within the wenduermiao early palaeozoic plate subduction zone in Inner Mongolia.The result indicates that the biggest shortened axis(Z) of strain ellipsoid which reflects the regional compressive Stress field dips SSW,dip angle is moderate.In the subduetion zone which extends 8～10km along E-W direction,the strain strength gradually increases from north to south,the ratio X/Z of Strain axis increses from 3.015 to 7.233.This paper discussed the geological event in which the Inner Mongolia palaeo-ocean plate subducted down under North China continental platform. A simulated test was carried out with gelatine as a test sample.The stress/strain curve was obtained.The theoretical value of the ratio was calculated of the strain axis to the compressive stress of deformed markers on the XZ plane.