LA-ICP-MS U-Pb isotope dating of volcanic single zircons from the Early Cretaceous Jiande Group in the Zhoucun-Yanxia cross section, Shouchang basin, western Zhejiang, SE China, at State Key Laboratory of Mineral Deposit Research, Nanjing University shows that the Jiande Group was formed during 134 ~ 115 Ma, the middle-late time of the Early Cretaceous. Subdividedly, the Laocun Formation ( Fm. ) , Huangjian Fm. , Shouchang Fm. And Hengshan Fm. Were dated as 134 ~ 125 Ma, 125 -118 Ma, 125 ~ 121 Ma and 121 ~115 Ma, corresponding to the Hauterivian-Barremian, early-middle Aptian, early Aptian and middle Aptian in age, respectively. However, the Jiande Group could range down to the lowest Upper Jurassic if the 4th bed (150~133 Ma) of the cross section is considered as a part of the group. It is proposed that the Huangjian Fm. Is the coeval volcanic sediment to the Shouchang Fm. And the Hengshan Fm. In space, but does not succeed beneath or above in sequence as former worker' s thought. It is suggested that the Shouchang Fm. Deposited in both the Shouchang basin and the Lishui basin was almost simultaneous, and the Hengshan Fm. Is roughly correlative with the Guantou Fm. In temporal.%利用LA-ICP-MS测试技术对浙西地区中生代晚期寿昌盆地典型剖面建德群9件凝灰岩和安山岩样品的锆石进行了同位素测年分析.结果显示:建德群锆石206pb/238U年龄加权平均值范围在134～115 Ma之间,属于早白垩世中—晚期；其所属的劳村组、黄尖组、寿昌组和横山组的锆石年龄分别是134 ～ 125 Ma、125～ 118 Ma、125 ～121 Ma和121～115 Ma,各自对应于欧特里夫期—巴雷姆期、阿普特期早—中期、阿普特期早期、阿普特期中期.由此认为,黄尖组的时代与寿昌组+横山组大致相当,前者与后两者横向可能为同时异相,并非上下关系；在寿昌和丽水两个盆地的寿昌组近乎同时,其上为时代大致相当的横山组与馆头组.
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