摘要
武功山花岗质穹隆伸展构造平面形态呈近椭圆形,长轴呈近东西向展布。花岗质穹隆伸展构造轴部主要出露中生代花岗岩类,其南北两侧为厚度较大、强烈韧性剪切的花岗质片麻岩,韧性变形时代为晚印支—燕山期;近东西向展布的晚古生代—中生代萍乡、安福盆地分别位于其北、南两侧的山前低地。武功山花岗质穹隆伸展构造具三层结构,由脆性变形带、低绿片岩相变质流变层-角闪岩相糜棱岩带和中生代似斑状花岗岩构成。中生代花岗岩群的东西向分布规律表明其侵入活动受东西向基底断裂的控制。深成花岗岩浆隆升作用是发生强烈动力变质作用的基本热源并影响动力变形作用的主要因素之一。武功山是一个从岩体核部朝南北两侧山外倾斜滑移的伸展构造。
In plan e the Wugongshan(shan means mountain in Chinese)granitic domal extensional tecton-ics is nearly elliptical in shape,with its long axis oriented in a nearly E-W direction.In the axial zone of the granitic domal extensional tectonics there is mainly outcrop of Mesozoic granitoids,and on its northern and southern sides occurs thick granitic gneiss that has undergone strong ductile shear.The age of ductile deformation is late Indosinian-Yanshanian.The Late Paleozoic-Mesozoic Pingxiang and Anfu basins which are distributed in a nearly E-W direction are located in piedmont lowlands on its northern and southern sides respectively.The Wugongshan granitic domal extensional tectonics has a three-layer structure,com-posed of a brittle deformation zone,a low greenschist-facies rheological layer-amphibolite-facies mylonite zone and Mesozoic porphyritic granite.The E-W-trending distribution pattern of the Mesozoic granite body swarm suggests that the granite intrusion was controlled by E-W-trending basement faults.The rise of plutonic granitic magma was the basic heat source generating strong dynamometamorphism and one of the main factors that influenced dynamic deformation.Wugongshan is an extensional tectonics formed by down-dipping slip from the core of the rock body toward the northern and southern sides beyond the mountains.
出处
《地质通报》
CAS
CSCD
北大核心
2002年第4期264-269,共6页
Geological Bulletin of China
基金
国家自然基金项目(No.40172067)
重点项目(No.40132010)和中国地质调查局综合研究项目(200113000053)资助。
