内蒙古苏尼特左旗二叠系的重新厘定及大地构造演化分析

探讨了苏尼特左旗地区二叠系地层单元的划分与时代归属，认为该区二叠系地层应包含大石寨组，哲斯组与林西组底部，重新厘定了该区二叠系剖面序列。通过对大石寨组火山岩岩石化学、稀土元素的分析，认为大石寨组所处的大地构造环境为活动大陆边缘，中朝板块与西伯利亚板块的最终汇聚时期应为早二叠世中期。

REVISION OF THE STRATIGRAPHIC DIVISION OF THE PERMIAN AND TECTONIC EVOLUTION IN THE SONID LEFT BANNER, INNER MONGOLIA

In the paper the authors discuss the stratigraphic division of the Permian and age assignment of the Permian stratigraphic units in the Sonid Left Banner area. It is considered that the Permian in the area should comprise the Dashizhai Formation, the Zhesi Formation and the base of the Linxi Formation. The authors revise the sequence of the Permian section of the area. On the basis of an analysis of the chemical composition and REE abundances of the volcanic rocks in the Dashizhai Formation, it is considered that this formation was tectonically located on the active continental margins and that the time for the final convergence between the Sino Korean plate and Siberian plate should be middle Early Permian.