新资深大断裂变质带特征、成因及活动演化

Characteristics, Genesis and Evolution of the Xinzi Deep Faulted Metamorphic Belt

在前人研究成果和野外调查基础上,对新资深大断裂变质带特征进行系统总结,从宏观构造、显微构造与组构、岩石矿物学、年代学和地球化学等多学科角度综合研究,分析了新资断裂带各类岩石组构成因,并建立了其活动演化期次。新资深大断裂变质带构造岩主要包括定向组构系列岩石和块状系列岩石,主要是由早期的韧性变形变质作用阶段和晚期的脆性破碎作用阶段先后作用形成。越城岭岩体西侧规模巨大的花岗片麻岩带应属新资深大断裂变质带的一部分,属早期活动的产物,其原岩为越城岭岩体,为断裂变质和动力热流变质作用形成。韧性剪切系列岩石按变形变质强度可分为高温高压韧性剪切带和中温高压韧性剪切带,表明韧性剪切作用具有多期性。新资断裂带活动演化主要经历了四个阶段,始于加里东期,至喜山期均有活动,现在的新资断裂带是经过多个阶段不同类型变质作用由东向西不断迁移和相互叠加的结果。

Based on the previous research results and field investigation,characteristics of Xinzi deep faulted metamorphic belt was systematically studied in the macroscopic structures,micrographic structures and fabrics,petrology,mineralogy,geochronology and geochemistry. The genesis was analyzed and the evolution model was established for all kinds of rock fabric. The tectonite of Xinzi deep faulted metamorphic belt mainly include the directional fabric rocks and the massive structures rocks,which reflects the formation of the earlier ductile deformation-metamorphism and the later brittle fracture. The huge granitic gneiss belt in the west side of the Yuechengling pluton should be part of the Xinzi deep faulted metamorphic belt and be the product of earlier activities. The original rock of granitic gneiss is Yuechengling pluton. The granitic gneiss was formed by fault metamorphism and dynamo thermal flow metamorphism. The ductile shear series rocks can be classified into high-temperature high-pressure ductile shear zone and moderate-temperature high-pressure ductile shear zone according to their deformation and metamorphic strength. It showed that ductile shear has multiple stages. The evolution of Xinzi fault belt can be divided mainly into four stages,from Caledonian to Himalayan. The present Xinzi fault zone is the result of successive migration and superposition of various types of metamorphism from east to west.