The sequences in Junggar basin were influenced by the major fault on the northwestern margin.The Jurassic is relatively thick in the footwall of the major fault

but is relatively thin or even absent in the hanging wall.However

based on available drilling

log

and seismic data in the study area

this paper recognized 2 structural sequences(JTS1

JTS2)

7 sequences(Ⅰ-Ⅶ)

and 10 system tracts in the Jurassic by employing classical sequence stratigraphy theory and approaches.It suggests that the occurrence of coal layers bears important significance in sequence demarcation and that the controlling factors for the Jurassic sequence stratigraphy on the northwestern margin of Junggar basin include tectonic movement

sediment supply

lake level rise and fall

and climate.Among them

the tectonic movement and lake level rise and fall are considered the most important.