Abstract:

Fan,braided stream,fan delta and braided delta sysem constitute the primary Jurassic coarse clastic sedimentary system.The system is characterised mainly by short axial directional transportation deposition in the fault depression of the Southeast Tarim Basin.The asymmetrical bilateral fractures within the graben resulted in the drift of subsidence center and depocenter towards the main fracture.Fan fan delta system developed on the abrupt of the fault depression,and braided stream braided delta sysem developed on the gentle slope.Dark mudstone of semi deep lake facises is good hydrocarbon source rock.The major petroleum source in the Jurassic oil bearing sandstone should be attributed to shallow marine source rocks derived from underlying Paleozoic.The stream channel bar,the underwater distributary channel of fan delta front and braid delta front are major reservoir sandtone bodies.