陕西洛南石门中寒武统变形鲕粒的有限应变分析

陕西省洛南石门中寒武世鲕状灰岩的有限应变分析表明,该点发生了压扁型应变;除由变形鲕粒最大扁平面构成的面理构造外,还发育一组拉伸线理。晚奥陶世,泰岭古岛弧与华北陆壳基底碰撞向北逆掩,导致华北南缘中元古代—早古生代盖层岩系由北向南逆冲推覆。鲕粒的变形史证实了这一地质事件所造成的地壳缩短作用的后继运动所造成的左行剪切作用。

FINITE STRAIN ANALYSIS OF MIDDLE CAMBRIAN DEFORMED OOLITES AT SHIMAN,LUONAN COUNTY, SHANXI PROVINCE,CHINA

Finite strain analysis of Middle Cambrian oolitic limestone at Shiman, Luonan County, Shanxi Province suggests that a flattening type deformation was formed in this region. In addition to planar fabric which is made from maximum flat planes of oolites, a stretch lineation structure showing remnant oceanic crust slices collided with the conineatal crust basement of North China plate and overthrust northward, that led to that the Middle Proterozoic—lower Paleozic covers of the southern margin of the North China plate were thrust from north to south. Deformation history of the oolites indicates that the crustal shortening is produced by this tectonic event and the sinistral shearing is produced by the consequent movement.