///In order to identify the predominant cycle of 0.405 million annuals and the absolute age of three datum horizons, a spectrum analysis has been conducted on well logging data from 11 wells that penetrated strata from the Dacangfang Formation to the Fenghuangzheng Formation. The results are as follow: 1) the age of top Dacangfang red bed, also known as the bottom Eh34 formation, can be calibrated by a 42.671 Ma age from the top lower Es4 red bed in the Dongying Depression near the Bohai Bay Basin; 2) the boundary between the bottom El and the top Eh1 can be calibrated by the bottom Dengying Formation’s age of 32 Ma from the Dongying Depression. The age of the bottom Eh1 is estimated as 34.468 Ma, there is a denudation plane of 0.4 million annuals between Eh2 and Eh1, and the average age of top El is 26.811 Ma; and 3) the age of the Pingyuan Formation is calibrated as 2.588 Ma according to the international stratigraphy chart, and the average age of the Fenghuangzheng Formation is  4.155 Ma.