吉林省金城洞绿岩带构造变形序列

STRUCTURAL DEFORMATION SEQUENCE OF THE JINCHENGDONG GREENSTONE BELT

金城洞绿岩带自晚太古代以来经历了多期变形：Ｄ＿１变形幕，形成片理、片麻理及无根褶曲，是深部构造层次的产物；Ｄ＿２变形幕，形成轴面片理及一系列轴向ＮＷ或ＮＷＷ向的紧闭同斜或平卧褶皱，并伴有英云闪长岩—奥长花岗岩侵入，是中深部构造层次的产物；Ｄ＿３变形幕，形成大型开阔褶皱，晚期形成韧性剪切带，是中浅部构造层次的产物。这三幕变形奠定了本区的基本构造格架。Ｄ＿４变形幕在中浅构造部位形成ＮＥ向开活褶皱。古生代以来，本区主要发生脆性变形。

Since the late Archean era,the Jinchengdong greenstone belt had suffered polystagestructure deformations.The deformation episode(D_1) formed schistosity , gneissic schistosityand the unrooted folds. They were products of the deep tectonic levels; D_2 deformationepisode formed axial plane schistosity, aseries of NW or NWW axial close congruous foldsand recumbent folds, associated with intrusion of quartz-biotite diorite and trondjemite. They were products of the middle-deep tectonic levels;D_3 deformation epidode formed openfolds and ductile shear belts, and they were products of the middle-shallow tectonic levels. These three deformations established the tectonic framwork of the Jinchengdong area. D_4 de-formation episode mainly formed open folds of NE strike in the middle-shallom level.SincePalaeozoic era,greenstone belt mainly occurred as brittle deformation.