本文采用白垩系三分方案,试图遵循陆相地层要与海相地层对比结果,把陆相地层纳入由海相沉积建立起来的年代地层系统中的原则,通过海相莫斯科皱蛤层、陆相塔伦让植物群、早波倍克期叶肢介群等晚侏罗世晚期生物群与 O—R(Onychiopsis—Ruffordia)中期植物群和晚期热河动物群等早白垩世生物群对比结果,将侏罗——白垩系界线分别划在云山组和珠山组、石河北组和城子河组、九佛堂组(泥河子组)和沙海组之间。下白垩统顶界划 This paper uses the Cretaceous trichotomy scheme to try to follow the principle that continental terrane should be compared with marine strata to include terrestrial strata in the chronostratigraphy system established by marine sediments. The results of the Late Cretaceous biota such as the late Jurassic biota in the flora of Tarungan, the early late Bobcock and other Late-Jurassic biota compared with the Oyzopsis-Ruffordia metaphase flora and the late Jehol fauna, The Jurassic-Cretaceous boundary line is divided between Yunshan Formation and Zhuoshan Formation, Shihebei Formation and Chengzihe Formation, Jiufotang Formation (Hehezi Formation) and Shahai Formation respectively. Lower Cretaceous top draw