摘要
太行－五台山区存在一巨型的北东向韧性剪切系统，由三条大型的韧性剪切带束构成。每条带束又由互相平行或小角度交接的一系列小规模韧性剪切带组成。其主要构造岩类为变糜校岩、糜棱岩、Ｓ－Ｃ糜棱岩等。该韧性剪切系统发生于晚太古代至早元古代的五台运动期间，经历过两期次韧性剪切作用，早期的差异应力约为１２ＭＰａ，晚期的差异应力约为３０ＭＰａ。应变速率分别为１．３６×１０（－１４）／ｓ和７．３６×１０（－１４）／ｓ，并指出巨型韧性剪切系统的发生将造成大规模的地壳流动，以此可以解释本区中地壳的大型低速体成因。
A giant ductile shear system trending in northeast direction exists in Taihang-Wutaishan region of North China. Based on our field work and laboratory studies, this system consists of three megaductile shear belts and each belt is composed of a number of small-scale parallel or low--angle intersecting shear zones.The main type of tectonite are mylonite, meta-mylonite,S-C mylonite,etc.This giant ductile shear system was formed during Wutai Movement from late Archean to Early Proterozoic and experienced two periods of ductile shearing. The differential stress in early period of shearing is about 12 MPa and the late is about 30 MPa. The formation of this kind of giant ductile shear system could cause large-scale material flow of the crust. We consider that this process should be related to the genesis of low-conductivity layer or body in the middle crust.
出处
《岩石学报》
SCIE
EI
CAS
CSCD
北大核心
1995年第3期279-291,共13页
Acta Petrologica Sinica
基金
国家自然科学基金
关键词
构造岩学
韧性剪切系统
剪切带
糜棱岩
Ductile shear system
Mylonite
Differential stress
Taihangshan
Wutaishan
