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土城子组是冀北-辽西地区中生界的关键层位,对土城子组年龄的确定直接关系到冀北-辽西地区以及中国东部侏罗纪与白垩系界限的确定,同时关系到中国东部相关的重大地质问题的研究.但是,由于土城子组以粗碎屑岩为主,其中化石的属、种较少,而且化石的穿时性强,所以古生物学家对土城子组的时代一直处在争论之中;同时,由于土城子组中的火山岩较少而使得同位素年代学的研究难度很大.因此,土城子组的年代一直未能定论.以冀北-辽西地区土城子组中的凝灰岩夹层等为测年对象,对冀北-辽西地区土城子组分布最广的承德盆地和金岭寺-羊山盆地进行了采样和测年,结合已有的测年数据,表明了冀北-辽西地区土城子组的年龄范围在147~136Ma之间,暗示了土城子组主体是早白垩世的产物.
Tuchengzi Formation is the key layer of the Mesozoic in North Hebei-Liaoxi area. The determination of the age of Tuchengzi Formation is directly related to the determination of the limit of Jurassic and Cretaceous in northern Hebei-western Liaoning and eastern China, and also relates to the eastern part of China However, since the Tuchengzi Formation is dominated by coarse clastic rocks, of which the genera and species of the fossils are few and their freshening time is strong, paleontologists have always been in the age of the Tuchengzi Formation At the same time, the study of isotopic chronology is very difficult because of the volcanic rocks in Tuchengzi group.Therefore, the age of Tuchengzi group has been inconclusive .In the northern part of Hebei-Liaocheng area, Of the tuff interlayer as the dating object, the sampling and dating of the Chengde basin and the Jinlingji-Yangshan basin which are the most widely distributed in the Tuchengzi Formation in the northwestern Liaoning-Liaoxi area were carried out. According to the existing dating data, The age range of the Tuchengzi Formation in the north-western Liaoning area ranges from 147 to 136 Ma, suggesting that the main body of the Tuchengzi Formation is the product of the Early Cretaceous.