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研究了中扬子区中二叠统层序界面和体系域特点,分析了层序样式的基本类型及其特征,建立了中扬子区层序地层格架,共划分出1个二级层序、6个三级层序(PSQ2—PSQ7),平均延时约1.7myr。海侵体系域为向岸退积的复合体,颜色普遍较深;高位体系域为向海进积的复合体,颜色相对较浅。总体上以H型样式为主,T型样式和TH型样式数量相当,反映中二叠世快速海侵缓慢海退的沉积特点,并且海侵海退幅度不大,水体中等。二级层序体系域和三级层序体系域南北向差异性不明显。
The characteristics of Middle Permian sequence boundary and system tract in the middle Yangtze region were studied. The basic types and characteristics of sequence patterns were analyzed. A sequence stratigraphic framework was set up in the middle Yangtze region, Six third-level sequence (PSQ2-PSQ7), the average delay of about 1.7myr. The transgressive system tract is an assemblage retreating to the coast, and the color is generally darker. The high-level system tract is a complex of sediments toward the sea, and its color is relatively shallow. In general, the H-shaped pattern is the mainstay. The T-shaped pattern and the TH-shaped pattern are quite similar in number, reflecting the sedimentary characteristics of the rapid transgression of the Middle Permian rapid seaward regression. The transgression of the transgression is not significant and the water body is medium. The difference of north-south direction of the second-level sequence system tract and the third-order sequence system tract is not obvious.