Abstract:

4 sequences and 10 sedimentary system tracts could be identified in the sedimentary strata of the Jurassic in Taibei Sag of the Turpan-Hami Basin. The lowstand system tract,transgressive system tract and highstand system tract developed under the control of ancient structure,paleotopagraphy, paleoclimate, sediment supply, and so on. In this paper,the sequence stratigraphy of the Jurassic in Taibei Sag is studied on the basis of geological,seismic, well logging and geochemical data. It is considered that sedimentary framework of the sag experienced great changes in Jurassic. From south to north,fluvial,swamp and lake deposits developed well in Early Middle Jurassic.Braid river deltaic and lake deposits developed in Middle Jurassic;and braid river,lake and fan deltaic deposits developed in Middle-Late Jurassic.Among them, coal bed of swamp and mudstone of deep-lake are good hydrocarbon soure rocks, braid river delta,fan delta and river channel sand bodies are good reservoirs, and lake mudstone is good cover rock. They constitute vertically favourable source reservoir-cap rock assemblages.