SCREENED TRAPS DEVELOPED ON THE FOOTWALL OF OVERTHRUST IN THE TARIM BASIN

There are a lot of overthrusts and screened traps developed on footwall of the overthrusts in the Tarim basin as a result of its long existence of compressional stress in the area.Two regimes of overthrust systems were formed during the Hercynian movement in the end of Early Permian and the Himalayan movement in the end of Oligocene respectively.Main hydrocarbon accumulation was happened during the two tectonic movements.The screened traps developed on footwall of overthrust were formed by secondary stress that was formed during the syn-thrusting or post-thrusting.Two walls of an overthrust showed different deformation with the hanging wall belong to allochthonous block and the footwall relatively unmoved and more or less is in situ.Therefore,traps on the foot wall of thrust are more favourable for hydrocarbon preservation.