Southwestern Tarim basin is located in the superposition area of Pal-Asia structural domain and Thetys structural domain.Laterally

Jurassic is in zonal distribution on the southern edge of southwestern Tarim

where a faulted basin system occurred in Jurassic period and might connected with the faulted basin on the southern edge of Karakum landmass to the west.During Jurassic period

deep water sedimentary area was located in a place where the marginal major normal fault had the largest displacement

while fluvial and swamp depositional environments were located on the superposition area of adjacent faults or in a place where the major fault had relatively small displacement.The largest fault displacement usually occurred in the middle part of the fault

and gradually decreased toward both ends of the fault

thus the subsidence occurring on the hanging wall would also decrease

and correspondingly

there would be the sedimentary environments of fluvial or alluvial fan fa-(cies).In addition to the piedmont zone

the Jurassic strata in southwestern Tarim were also developed in a series of fault-controlled lake basins.The development of oil source rocks had been confined to the semi-deep lacustrine sediments.