摘要
在1:5万羊曲幅区域地质调查中,通过采取非史密斯地层理论及构造岩片为核心的多重划分方法,确定羊曲地区分布的元古宙地层的形成时代为古元古代,变质程度属低角闪岩相,为红柱石一矽线石型低中压变质相系。经区域地层对比,该套地层为扬子地块裂解块体的一部分,其与二叠纪火山弧岩片及弧前复理石岩片共同构成昆秦接合部构造混杂带的北东端。
In the 1.50000 regional geological survey in Yangqu area,through the multi- division method,which taking the Non-Simith strata theory and tectonic slice as its core parts,the forming age of Proterozoic strata distributed in Yangqu area is determinated as Pa- leo-Proterozoic era (with an U-Pb isotopic age of 2330+50 Ma).The strata are a low to middle metamorphic series of andalusite-sillimanite type and belonged to low amphibolite fa- cies .It may be a part of the splitting massives of Yangzi massif and constituted the north- eastern end of tectonic melange belt in junction part of Qinling and Kunlun with the Permian volcanic arc and the foreare flysch slice.
基金
1:5万羊曲幅区域地质调查项目成果
