胶东焦家断裂带韧性变形特征

DUCTILE DEFORMATION CHARACTERS IN THE JIAOJIA FAULT ZONE IN THE JIAODONG AREA,SHANDONG PROVINCE

焦家断裂带晚期表现为强烈的脆性变形,但其早期则表现以糜棱岩组合、对称组构等为特征的韧性变形。应变测量和差应力估算表明:从焦家主断裂到望儿山支断裂的糜棱岩变形标志体有主轴比变小、K值增大、古应力值逐渐变小的趋势,韧性变形阶段差应力方向为NWW SEE。焦家断裂带早期是在中温(300℃～500℃)、中等围压(0 27GPa～0 49GPa)条件下形成的以压扁作用为主的左行韧性变形带。

The Jiaojia fault zone is characterized by ductile deformation in the early stage and brittle fracturing in late stage.The early ductile deformation have typical mylonite associations,symmetry fabrics.Finite strain measurements and estimate of differential stress value show:from Jiaojia major fault to Wang ershan secondary fault,major axis ratio of deformation keybody dropped a little、Kvalue increased a little,the direction of differential stress is NWWSEE trending. It is sinistral ductile deformation zone dominated by flatting at medium temperature of 300℃～500℃ and middle confining pressure of 027～049GPa in the early.