Cyclic sedimentary record of "red-greyish green" beds in the first Member of Eocene Kongdian Formation(Ek1), Dongying Sag: An example from the Well Wang 46 in Wangjiagang area oleh Tao Nian, Zaixing Jiang, Huimin Liu, Yiming Huang, Yougen Deng, Jiayi Meng, Yang Li