Cicatricosisporites, Klukisporites, Densoisporites and Aequitriradites were obtained from the Huoshiling, Shahezi and Yingcheng formations. These sporopollen fossils are characteristic of Early Cretaceous strata in the world. The U-Pb zircon ages of volcanic rocks indicate that the upper Huoshiling Formation (124.9±2.5) Ma is of Barremian age, the Yingcheng Formation (zircon ages mainly 105～112 Ma) of late Aptian-early Albian age, the lower Qingshankou Formation (91.35±0.48 Ma) of Turonian age, and the lower part of the second member of the Nenjiang Formation (83.68±0.47 Ma) of Santonian age. Magnetostratigraphy shows a long term normal magnetozone from the Quantou Formation to the first member of the Nenjiang Formation, this magnetozone may be correlated to the upper part of C34n.From the second to fifth member of the Nenjiang Formation, the magnetic polarity was reversed, and this interval can be correlated to chron C33r in the GPTS.
