On the basis of integrated studies of seismic data, cores, well logs and palaeontological stratigraphy of the East Fukang Slope, Junggar Basin, six stratigraphic sequences or two tectonic sequences are recognized from the Jurassic System of the study area.Difference of the spatial distribution of the sequences and sedimentary facies indicates that, from the period of Badaowan Formation to the period of Xishanyao Formation, the main sedimentary provenance was in the north of the basin. The lower tectonic sequence was characterised by uplifting of the north and relatively balanced subsidence of the south; but from Toutunhe Age to Kalazha Age, the south area was uplifted and became the main sedimentary provenance, and thus the lake basin area decreased abruptly.In the study area, there are two sedimentary systems. The main one is an alluvial fanbraided riverdeltalake system, and the minor one is a meandering riverdatlalake system, both of which are developed along the short axis of the basin.From the early Jurassic Epoch to the middle Jurassic Epoch, Junggar Basin was dominated by warm humid climate, with two short hot and dry episodes in the Sangonghe and Toutunhe Period. In the late Jurassic stage, the climate became semiarid or arid, which had a great contribution to the decrease of the lake area.
