摘要
由早期绿岩、变质ＴＴＧ杂岩及闪长岩为主构成的辽南古陆壳，在新太古宙末期—古元古代初期遭受了四期构造变形，以主期变形（第三期）最为显著。该期变形重塑了古陆壳上的太古宙岩石，形成密集而普遍的区域透入性主期片麻理（Ｓ３），矿物线理（Ｌ３）及“顺片”掩卧褶皱（ｆ３），并伴随高温低压条件下的角闪岩相区域变质作用，变形机制属中构造环境下由南至北的韧性水平剪切滑脱，其动力学成因可能为诱发古元古代辽东裂谷的地幔软流圈热羽的早期活动，导致辽南古陆块上部硅铝壳相对于壳下岩石圈作反向滑脱的壳下拆离作用。
Archean Palaeocontinental crust in South Liaoning,mainly composed of early stage greenstone,metamorphosed TTG complex and diorite,had experienced 4 stages of structural deformation from Late Neoarchean to Late Palaeoproterozoic eras, in which the third stage was the most obviously deformed as the main stage.In the third stage,the structural deformation remolded Archean rocks on the palaeocontinental crust with densely and widely spreading regional penetrative main stage gneissosity(S 3),mineral lineation(L 3) and bedding'recumbent folds (f 3),accompanying amphibolite facies regional metamorphism and S N ductile horizontal shearing deformation.The dynamic origin probably is the early stage plume activities of the mantal rheosphere,which resulted in the formation of Palaeoproterozoic Liaodong rift and Si Al crust in the upper part of Paleocontinental block occuring subcrustal detachment in opposite directions wit subcrustal lithosphere.
关键词
辽南
古陆壳
片麻理
褶皱
构造变形
构造演化
south Liaoning
paleo continental crust
gneisosity
fold
plume
subcrustal detachment
