摘要
内蒙古查干通格地区中深构造相韧性剪切变形所涉及的地质体为新太古代变质表壳岩和变质深成岩体,构造形迹保存较好的为变质深成体,其岩石变形强弱不均一,片麻岩发生糜棱岩化,面理及矿物拉伸线理发育亦不均一。强变形域中糜棱片麻理均匀而密集、间隔多小于1cm,石英多呈拔丝状,矿物相对集中呈条纹状、条带状,定向分布,构成矿物拉伸线理非常发育,局部可见S-C组构、书斜构造等;弱变形域中眼球状构造非常发育,眼球大小不一,长轴定向,与两侧拖尾构成"σ"型碎斑系,片麻理不均匀,间隔多在2cm以上;石英呈压扁状、竹节状,集合体呈透镜状定向分布。宏、微观的"σ"系及S-C等组构均显示北东向的斜逆冲型韧性剪切变形,变质程度相当于高绿片岩相—低角闪岩相。
Ductile shear deformation of middle- deep structure facies occured in New Archean in metamorphic sedimentary rocks and metamorphic plutonic intrusive body, and formed the strong deformation field and weak deformation field. Mylonite foliation, striped structure, wiredraw structure of quartz, mineral stretching lineation, S- C fabric and 'book- inclined'structure were developed in the strong deformation field.Lenticular aggregate, gneissosity, flat form texture and 'bamboo- stanza'form texture of quartz and 'σ' type clastic phenocryst system, which was constituted with eyeball- form structure and the drag tail structure; were developed in the weak deformation field. Macroscopic and microscopic characteristics of 'σ' system and S- C fabric etc, show that the ductile shear deformation of middle- deep structure facies was belonged to north- east diagonal thrust type, and its metamorphism degree was between the high greenschist facies and low amphibolite facies.
出处
《西部资源》
2014年第2期184-187,共4页
Western Resources
基金
内蒙古自治区地质矿产调查综合研究项目(编号:KD68)
关键词
中深构造相
韧性剪切带
变形特征及意义
middle-deep structure facies
ductile shear deformation
deformation age
