柴达木盆地周边断裂超微构造变形特征及其应力-应变环境

Deformed characteristics of super-microstructure and stress-strain environment of perimeter faults of Chaidamu Basin

通过断裂超微变形构造分析 ,对柴达木盆地周边断裂构造发育的应力 -应变环境进行了较为深入的探讨。研究结果表明 :新高泉断裂超微构造以密度较低的平直位错线为典型特征 ,反映了相对较低的应力 -应变环境 ;大头羊逆冲断裂位错密度高 ,位错形态复杂 ,呈弯曲状延伸 ,局部发育位错环 ,应力 -应变环境较高 ;绿梁山逆冲断裂的超微构造以亚颗粒的普遍发育为显著特征 ,表明应变环境已达恢复阶段 ;纳赤台逆冲断裂的超微构造较为复杂 ,位错线、位错壁和亚颗粒都有不同程度的发育 ,表明变形的复杂性。根据超微构造的特征 ,这对不同断裂的古构造应力和应变速率进行了计算。

Stress strain environment of perimeter faults of Chaidamu Basin was deeply researched through analysis of super microstructure of the faults.The research results showed as the following.Flat and straight dislocations of lower density of super microstructure are typical feature of Xingaoquan fault and reflected relatively lower environment of stress strain.The Datouyang fault is characterized by high dislocation,complex dislocation shape,which stretched meanderingly and developed circular shaped dislocation locally.All of these reflected that stress strain environment of Datouyang fault is higher.The remarkable character of Luliangshan thrust is sub grain developed universally,which indicates strain environment getting into recovery stage.The super microstructures of Nachitai thrust are more complicated.Development of different degree of dislocation,dislocation wall and sub grain showed complex of deformation.According to characteristics of super microstructures,the paleostructure stress and strain rates are also calculated.