辽东半岛四堡旋回地质作用及其构造意义——以辽东榆树砬子组为例

建立在岩石组合、变质、变形和同位素年代学基础上的研究成果表明,辽东半岛榆树砬子组是经历了绿片岩相浅变质的滨浅海相单陆屑碎屑岩含铁建造,其时代应归属中元古代.在下伏辽河群褶皱回返之后上覆永宁组堆积之前其经历了四堡旋回构造变形,并与四堡旋回末期快速堆积的永宁组共同构成中间构造层,使得辽东地区地壳具多元化的三层式结构.

GEOLOGIC PROCESS OF THE SIBAO CYCLE IN THE LIAODONG PENINSULA AND ITS TECTONIC SIGNIFICANCE:A case study of the Yushulazi Formation in eastern Liaoning Province

The study on the rock association, metamorphism, deformation and isotopic geochronology shows that the Yushulazi Formation in Eastern Liaoning is a single terrigenous clastie iron formation with metamorphism of greenschist facies, lts age belongs to Mesoproterozoic. The Yushulazi Formation underwent the tectonic deformation of Sibao Cycle during the period between the folding of the underlying Liaohe group and the sedimentation of overlying Yongning formation. The Yushulazi Formation, together with Yongning Formation, which quickly accumulated in the end of Sibao Cycle, formed the middle structural layer, making the three-layered structure of the crust in Eastern Liaoning region.