越城岭花岗岩体定向构造的成因研究

Oriented structures in Yuechengling granite pluton

越城岭花岗岩体定向构造的成因类型有 5类 ,即 :断裂变质与剪切深熔构造、韧性剪切构造、残留区域变质构造、拟态交代与生长构造、碎裂流动构造。其中断裂变质与剪切深熔构造是成岩的基础构造 ,韧性剪切构造是最重要的叠加构造。韧性剪切指向为正 -左旋剪切 ,Δσ =5 5～ 135MPa ,ε′=9 6× 10 -12 ～ 3 5× 10 -10 /s,变形变质相为绿片岩相。岩体西部片麻状岩带的形成与新资断裂长期活动有关。

The oriented structures in the Yuechengling granite pluton include fault metamorphic and shear anatectic,ductile shear,relic regional metamorphic,mimetic replacement and growth and cataclastic flow structures,among which the fault metamorphic and shear anatectic structures are basic rock forming structures,and the ductile shear structures are the most important superimposed ones. The shear sense of ductile shear zones is normal sinistral with the paleo stress difference ranging from 55 to 135 MPa and paleo strain rate from 9.6×10 -12 to 3.5×10 -10 per second,resulting in forming of greenschist facies distortional metamorphism. The gneissic structures in the west part of the Yuechengling granite pluton might be associated with the long term activatity of the Xinning Ziyuan fault.