In Ganchaigou formation of the Neogene the active mantle source rock-magma resulted in widely depressed process, occurring the largest lacustrine overflow and deposit.

• 新近纪上干柴沟组沉积时期由干幔源岩浆的活动使盆地以沉降作用为主，达到全盆最大湖泛面，发育湖相为主的沉积；