安徽贵池地区二叠系孤峰组露头层序地层

CHARACTERISTICS OF OUTCROP SEQUENCE STRATIGRAPHY OF THE PERMIAN GUFENG FORMATION IN THE GUICHI AREA, ANHUI

依据实测地层剖面的详细研究,将二叠系孤峰组分为四个三级层序,每个三级层序跨时平均约1.25Ma,其高频变化表现为:海侵体系域的粒序变化主要表现为下粗上细的正粒序组构特征,总体表现为自下而上沉积水体由浅变深的退积型旋回;高位体系域的粒序变化主要表现为下粗上细的正粒序组构特征,总体表现为自下而上沉积水体由深变浅的进积型旋回。

The Permian Gufeng Formation strata in the Guichi area of Anhui Province may be divided into 4 third order sequence,and each may be about 1.75Ma,usually having TST,CS and HST,but same se- quence no CS,the high-frequency sequences in the study area are of two types:the normal grading succes- sion being coarse in grain size below and fine above in HST,and the retrograding sequence of being from shallow to deep in water depth; the inverse grading succession being coarse in grain below and fine above in TST,and the prograding sequence being from deep to shallow.