Abstract:

The study of sequence stratigraphy developed continuously from sequence stratigraphy framework and depositional system tract analysis of basin scale to high-resolution and microfacies scale.Refine outcrop and well logging analysis show that there can be divided into 3 3^rd order sequences, 6-8 4^thorder sequences and more than 20 parasequences in Shanxi Formation and Taiyuan Formation of Helanshan-Zhuozishan area.The 4^th order sequence generally are bounded by incised distributary channel, tide and fluvial mix channel, near mouth bar or scoured base of shoreface deposit, coal base developed on early transgression and delta front baselap surface developed in low stand system tract.These surfacies can be extensively traced in the study area, and their recognition and subdivision are critical factors of high-resolution sequence stratigraphy framework foundation.The sequence stratigraphy simulation applying SSMS system may reveal the control of sea level change and tectonic subsidence on sequence formation process.The simulation results show that symmetrical and non-symmetrical relative sea level change formed obvious different sequence compositions.The fast rise and slow drop process of sea level interpreted the 4^th order sequence composition character and coal accumulation regular pattern.The transformation of later high stand system tract and transgression is the most favorable period to form coal deposition widely.

Key words:  high-resolution sequence stratigraphy, dynamic simulation, coal accumulation, Carboniferous-Permian, Helanshan-Zhuozishan area