摘要
为厘定浙江省天台县天台盆地含恐龙骨骼及蛋化石地层的时代,在赋存恐龙骨骼及蛋化石的赖家组和赤城山组陆相红层中选取了晶屑凝灰岩夹层,分别进行了精确的锆石SHRIMP和LA-ICP-MS U-Pb定年。结果显示,赖家组中上部和赤城山组中部晶屑凝灰岩(夹层)的成岩时代分别为100±1 Ma和92±1 Ma,表明赖家组沉积于早白垩世晚期—晚白垩世早期,而赤城山组形成于晚白垩世,二者连续沉积构成了天台盆地含恐龙骨骼和蛋化石的地层;据此推断,与赖家组呈整合接触的下伏塘上组地层的形成时代早于早白垩世晚期(>100 Ma),而天台盆地恐龙的灭绝时代晚于晚白垩世早期(<92 Ma)。上述研究结果亦可为开展天台盆地与浙东其他盆地之间进行地层划分对比可靠的年代学依据。
In order to determine the precise age of dinosaur-bearing strata in the Tiantai Basin in Zhejiang Province, tuff interlayers in the Laijia and Chichengshan formations which contain thousands of fossil dino- saurs＇ bones and eggs were selected for zircon age dating. The results show their zircon U-Pb ages are 100±1 Ma （by SHRIMP） and 92±1 Ma （by LA-ICP-MS）, respectively. Thus, the Laijia Formation was de- posited in the late Early Cretaceous to the early Late Cretaceous and the Chichengshan Formation in the Late Cretaceous. Continuous deposits from the late Early Cretaceous to the Late Cretaceous constitute the dinosaur-bearing strata in the Tiantai Basin. It follows that the underlying Tangshang Formation is Early Cretaceous in age, and formed before the late Early Cretaceous （〉100 Ma） while the dinosaur extinction in Tiantai Basin was later than 92 Ma. The results also provide new data to improve the stratigraphic cor- relation between the Tiantai Basin and other sedimentary basins in eastern Zhejiang Province.
出处
《地层学杂志》
CSCD
北大核心
2016年第3期272-277,共6页
Journal of Stratigraphy
基金
国家自然科学基金(No.40672041)
国家自然科学基金青年基金(No.41002024)
中国地质调查局项目(DD20160037)联合资助
关键词
年代学
赖家组
赤城山组
白垩纪
天台盆地
浙江
zircon U-Pb age, Laijia Formation, Chiehengshan Formation, Cretaceous, Tiantai Basin, Zhejiang
