The distribution of Permian in northeast China is large, and its sedimentary facies types includes half deep sea facies, offshore facies, shore shallow lake facies and half-lake facies. The region in northeast China is in a continental-margin and epicontinental sedimentation environment during Lower Permian to Middle Permian, and the deposition center is in the Wendouermiao-Xilamulun river area. In the Later Permian, this region was a large-scale depression basin, and all suture lines already were closed, while the earth crust was lifting and the sea water was withdrawing, thus the most areas became continental depositing, and partial areas formed residual-marine depositing. As a whole, the rule of sedimentary facies of this region presents a gradual transformation from marine facies in the Early Permian to land facies in the Late Permian. The sedimentation of this region in Late Paleozoic was controlled by the suture line of Xilamulun river, and the suture line became to be closed gradually from west to east during Permian and closed completely until the Late Permian, and the closed time is earlier in west and later in east.%东北地区二叠系分布广泛,沉积相类型主要为半深海相、滨浅海相、滨浅湖相和半深湖相等.早二叠世—中二叠世东北地区主要处于大陆边缘浅海沉积环境,面积大,沉积中心位于南部温都尔庙—西拉木伦河东西向条带区.晚二叠世东北地区为大型坳陷型盆地,东北地区各缝合线均已闭合,随着地壳抬升,海水退出,大部分地区为陆相沉积,局部有残留海相沉积,总体上具有从早二叠世到晚二叠世由海相向陆相逐渐转变的规律.西拉木伦河缝合带对晚古生代沉积起控制作用,在二叠纪整个缝合带由西向东逐渐拼合,直至晚二叠世,两板块拼合完成,闭合时间具有西早东晚的特点.
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