Tazhong 4 Oilfield is originally formed at later Hercynian, and then petroleum is entrapped at Yanshanian.Finally, it is reconstructed and reallocated in Himalayan.

• 塔中4油田最初形成于晚海西期，燕山期又经历了一次重要的成藏过程，喜山期还有一次改造再分配的过程。