Abstract:

Kuqa Depression is a "dustpan" shape depression with steep slope in the north side andgentle slope in the south side.Fan-deltas and braid river deltas are developed on its northmargin while shore deposit, shallow lake deposit and meandering river deltas are developedon the south margin. The fan-deltas are characterized by gravity flow deposit associated withtractive current deposit, Both of the deposits were resulted by sudden catastrophic event. Theformer is primarily massive conglomerate; the later is mainly lenticular channel sand bodiesdistributed within the gravity flow deposit, The normal tractive current deposit of the braidriver deltas is primarily bedded channel sand bodies in which lateral aggradation and crossbedding are well developed, The fan deltas and braid river deltas are independant but closelyconnected to each other,their evolution is controlled by the intensity and range of faulting activity in depression margins.