摘要
庐山出露的变质核杂岩的构造层次具有典型的三层结构,即最上面的未变质沉积盖层、中间韧性流变层、核部的变质基底,其间分别以上剥离断层和拆离断层为分界线。上部沉积盖层以脆性变形为主,中间韧性流变层变形程度不一,但远离拆离带变质变形逐渐减弱,而核部的变质基底以强塑性变形为特征。对变质核杂岩南北两条地质剖面的分析,得到三个构造层次的岩石变质变形及岩性变化特征。区域动力学分析反映变质核杂岩东部原拆离带在五里正断层附近。拆离带中多硅白云母压力计得出的变质压力为0.6-1.1 GPa;锆石U-Pb年龄测试得到变质核杂岩的隆升时代为早白垩世。
The tectonic level of metamorphic core complex outcropping in Lushan Mountain has a typical threelayer structure. Namely unmetamorphosed sedimentary cover on the top,intermediate ductile rheological layer,the metamorphic basement of the core. And stripped fault and detachment fault are the dividing line of them. The upper sedimentary cover is given priority to brittle deformation,and the intermediate ductile rheological layer has varying degree of deformation,the metamorphism and deformation becomes weaker gradually when away from the detachment belt,while the metamorphic basement of the core is characterized by severe plastic deformation. Rock＇s metamorphism,deformation and lithologic variation characteristic of three tectonic level can be obtained through the analysis of south and north geological sections of Lushan metamorphic core complex. The former detachment belt in the east of metamorphic core complex is near the Wuli normal fault through the analysis of regional dynamics. The metamorphic pressure calculated by phengite manometer is 0. 6 - 1. 1 GPa; The uplift age of the complex tested by zircon U-Pb dating is Early Cretaceous.
出处
《地质论评》
CAS
CSCD
北大核心
2015年第4期752-766,共15页
Geological Review
基金
国家自然科学基金项目(编号41272222)
中国地质调查局科研项目(编号1212011121114)的成果
关键词
庐山变质核杂岩
伸展拆离
构造层次
变质变形
多硅白云母压力计
U-PB年代学
庐山
Lushan metamorphic core complex
extensional detachment
tectonic level
metamorphism and deformation
phengite manometer
U-Pb geochronology
Lushan Mountain
