CORRELATION BETWEEN YIXIAN FORMATION IN WESTERN LIAONING AND DADIANZI AND XIGUAYUAN FORMATIONS IN NORTHERN HEBEI

The comprehensive correlation between the Yixian Formation in western Liaoning and the Dadianzi, Xiguayuan Formation in northern Hebei has long been a controversial problem. Based on the biostratigraphy and isotopic ages, the Laogonggou (Lujiatun),Yenangou (Xiatulaigou),Jianshanggou (Zhuangchengzi) beds of Yixian Formation may be correlated with the lower part (1st and 2nd Members and the lower part of 3rd and 4th Members) of the Dadianzi Formation, suggesting that the Dakangpu beds of the Yixian Formation correlate with the upper part (the upper part of 3rd and 4th Members) of the Dadianzi Formation;the Xiguayuan Formation is largely equivalent to the Jingangshan bed of the Yixian Formation