论浙江中生代晚期地层划分

中生代晚期，浙江先后形成了寿昌型、永康型和金衢型三种不同构造类型的盆地，三者呈叠加关系，其堆积物属于３个地质时期。在理顺其层序的基础上，通过对３个不同时期古生物群和同位素年龄资料的综合分析，认为衢江群（天台群）属于早白垩世晚期一晚白垩世；永康群属于早白垩世中晚期；建德群（磨石山群）属于晚侏罗世－早白垩世早期。如果采用１３０Ｍａ作为侏罗－白垩系划界时标，其界线应划在横山组与寿昌组及相应的岩组之间。

Division of the Late Mesozoic strata in Zhejiang

During the Late Mesozoic, three kinds of basin in different structural directions,the Shouchang type, the Yongkang type and the Jinqu type, were formed one after another and in turn superimposed on each other. The accumulated matters may be assendingly divided into the Jiande Group (Moshishan Group), Yongkang Group and Qujiang Group (Tiantai Group).The fossils in these five groups have been studied by many specialists concered and were grouped in general into the Jiande, Yongkang and Qujiang Faunas of different ages.Based on multidisciplinary analysis of isotopic age data and stratigraphic sequences 105-110Ma was suitable used as the hasal boundary age value of the Qujiang Group(Tiantai Group). The hasal boundary age of the Yongkang Group was inferred to be 120-125Ma. The hasal boundary age of the Jiande Group (Moshishan Group) should be 150-155Ma. If 130Ma is used as the demarcation time marker between the Jurassic and Cretaceous Systems, the hasal boundary should be drawn the Hengshan and Shouchang or other corresponding Formations.