CHARACTERISTICS OF SEQUENCE STRATIGRAPHY AND THE ANALYSIS OF CONTROLLED FACTORS OF THE COAL ACCUMULATION ABOUT THE LOWER JURASSIC IN THE ZHONGGUAI ZONE OF JUNGGAR BASIN

Based on the previous study results of sequence stratigraphy in Junggar basin,according to the drilling,logging and seismic data,classify sequence of the lower Jurassic in the Zhongguai zone of northwestern margin of Junggar basin,it sum up the identification of the boundaries of sequence and system tract,and the lower Jurassic has been divided into four sequences and seven system tracts,at the same time the characteristics of the four sequences’ composition have been described.Through analysis on the characteristics of coal-bearing strata,it finds that the main coal layers develop in the transgressive systems tracts of JSQ1 and JSQ3,the author of this paper argues that the transgression is the favorable period of coal accumulation in the studyarea,and the coal accumulation is mainly controlled by tectonic movement.the supply of source、climate and sedimentary environment.