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乌拉山群的变质 -变形问题一直有不同的认识[1～ 3] 。该文以固阳地区 3幅 1∶5万区调资料为基础 ,结合 90年代以来周边地区 1∶ 5万区调成果 ,提出晚太古宙乌拉山群经历了两期主要的构造变形。第一期为伸展体制下近水平分层剪切形成的固态流变褶皱和高温顺层韧性剪切带 ,属高角闪岩相 -麻粒岩相 ,变形时间为太古代末 ;第二期构造变形为地壳抬升之后的挤压体制下 ,中、浅层次的紧闭同斜相似褶皱——主期褶皱和低温韧性剪切带 ,形成时代为早元古代。
Wulashan group metamorphism - deformation problems have been different understanding [1 ~ 3]. Based on the data of 1 area of 1: 50000 in Guyang area and the results of 1: 50000 area adjustment in the surrounding area since the 1990s, it is suggested that the Late Archean Wulashan Group experienced two major tectonic deformations. The first phase is a solid rheological fold and high temperature bedding ductile shear zone formed by near-horizontal stratified shear in the extensional system, belonging to the amphibolite facies-granulite facies with a deformation time of the end of the Archean. The second structural deformation Under the crustal uplifting crustal system, the shallow and middle tight synclinal similar folds - the main fold and the low temperature ductile shear zone formed during the Early Proterozoic.