关键词: 东北地区, 二叠纪, 沉积特征, 原型盆地

Abstract:

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.

Key words: northeast China, Permian, depositional characteristic, proto-type basin