From Chang 3 to Chang 2 stage, sedimentary distribution on surface and sedimentary association on cross section showed a characteristic durative propagation and stepwise overlap toward delta plain.

• 长3到长2期，远源砂质辫状河沉积在平面展布和剖面组合上均表现出向三角洲相区持续推进和逐步超覆的特点。