Abstract: To recognize the break zone exactly is critical to establish the distribution model, the sequence constitution pattern, and the sequence development boundary of lower system tracts in terrestrial rift basins. It is also the basis for the exact prediction of subtle lithologic traps and subtle oil and gas reservoirs. It is indicated by the research on Nanyang Depression that the break zone on the northern slope is developed as a result of the slip of normal faults of the southern depression on the negative plane. On the basis of the sequence stratigraphic framework of the break zone, the characteristics of the gentle slope-break zone of the depression and its controlling factors are summed up. Combining the theory of break zones and the exploration practice in Nanyang Depression, the model predicting favorable reservoir bodies distribution is built, which is of great significance to the oil and gas exploration henceforth.

Key words: Nanyang Depression, break zone, sequence stratigraphic framework, oil and gas exploration