在内蒙古赤峰北部双井及其附近地区进行１／５万区调过程中，于西拉木伦河北岸发现了一些重要的地质资料：双井古陆及其物质组成；早二叠世早期复理石建造；石炭纪一早二叠世早期的蛇绿岩及其构造侵位；侵位于双井古陆的早二叠世同碰撞Ⅰ型、Ｓ型二长花岗岩；早二叠世晚期的磨拉石建造；早二叠世末西拉木伦河断裂带的韧性右行走滑及小苇塘岩片的构造侵位等。这些资料为加深对西拉木伦河断裂带的认识提供了可靠的依据。从而认为西拉木伦河断裂带为古蒙古洋板块与中朝板块最终碰撞缝合的位置，缝合时间为早二叠世早期末 Some important geological data were found on the north bank of the Xilamulun River in the area of ​​Shuangjing and its vicinity in the northern part of Chifeng, Inner Mongolia: the ancient Shuangjing and its material composition; the early Early Permian complex Marble construction; Early Carboniferous-Early Permian ophiolite and its structural emplacement; Early Permian collisional type I, S-type monzonitic granite in Shuangjing old land; Late Early Permian Lala stone construction; the ductile right-lateral strike slip of the Xilu Mulanhe fault zone in the Early Permian and the structural emplacement of the small reed ponds. These data provide a reliable basis for deepening the understanding of the Xilamulunhe fault zone. Therefore, it is concluded that the Xilamulunhe fault zone is the location of the final collision between the ancient Mongolian plate and the Sino-Korea plate. The suture time is the early Early Permian