中华鸟龙与孔子鸟类的时代——辽西义县组火山凝灰岩激光^(40)Ar/^(39)Ar年龄测定  

Age of Sinosauropteryx and Confuciusornis——^(40)Ar/^(39)Ar laser single grain and K Ar datingof the Yixian Formation, NE China

作　　者：罗清华[1] 陈丕基[2] 邹东羽 孙贤鉥 李寄鉥 

机构地区：[1]台湾大学地质系 [2]中国科学院南京地质与古生物研究所,南京210008 [3]16GiffenClose

出　　处：《地球化学》1999年第4期405-409,共5页Geochimica

基　　金：国家自然科学基金!(编号:49812020);中国科学院重大研究基金!(编号:KZ951- B1- 410)

摘　　要：利用ＮｄＹＡＧ 激光ＡｒＡｒ 测年法，对产自辽西北票四合屯尖山沟地区义县组底部孔子鸟和中华鸟龙湖相层中火山凝灰岩中的黑云母单晶做了５０ 多次分析， 得出的同位素年龄值为（１４７ ±１．８） Ｍａ ， 用ＫＡｒ 法测得孔子鸟化石外面的火山包裹层的结果为（１４７．３ ±３ ．３）Ｍａ ，两者年龄时代相当吻合，同为晚侏罗世晚期（ 晚提唐期） ，比德国始祖鸟层的时代略晚，也与孔子鸟特征和美颌龙类———中华鸟龙指示的地质时代吻合。Recent discoveries of Mesozoic feathered theropod and bird fossils (Liaoningornis, Confuciusornis, Caudipteryx, Protarchaeopteryx and Sinosauropteryx) from the Yixian Formation, Liaoning, NE China have provided an excellent opportunity to examine the long running debate on the hypothesis that birds evolved from dinosaurs, and to reveal the early evolution of feathers. K Ar dating of volcanic ash from the coverage of Confuciusornis Sanctus Hou et al.yields (147.3±3.3)Ma for the age of the fossil.40Ar/39Ar laser single grain dating on individual biotite grains collected from a volcanic bed, about 20 m above the stratigraphic position of the fossil bed, in the lower part of the Yixian Formation yields ages in the range of 136.2～155.4 Ma[mean age of (145.3±4.4) Ma] with an intercept age of (147.1±1.8) Ma. These two ages are in excellent agreement and thus, resolve a controversy regarding age of these fossils. It is now firmly established that the feathered theropods and early birds in NE China lived in the late Jurassic, about the same time period as Archaeopteryx found in Bavaria.

关 键 词：孔子鸟 晚侏罗世 中华鸟龙 氩40-氩39测年 

分 类 号：Q915.652[天文地球—古生物学与地层学] Q915.864[生物学—古生物学]