摘要
通过对西藏冈底斯南带林周盆地中 3个岩组样品的40 Ar 3 9Ar定年 ,初步建立了该剖面林子宗群火山岩形成的同位素年代时序格架 :底部典中组的下限年龄为 6 3.32± 0 .89Ma;中部年波组为 5 4.16± 0 .49Ma;上部帕那组下限年龄为 38.7± 0 .40Ma .。指出至少在林周盆地剖面 ,林子宗群火山岩的形成时代为早第三纪 ,而非晚白垩纪。
The time frame of the volcanic rock of the Linzizhong Group, Tibet has been determined by 40Ar/ 39Ar dating of three samples from Linzhou Basin, the southern Gangdise. The dating results are: Dianzhong formation, which is the oldest, 63.32±0.89 Ma; Nianbo formation, 54.16±0.49 Ma; Pana formation, which is the youngest, 38.7±0.40 Ma. We conclude that the timing of formation of volcanism in this area is during the Eogene, not later Cretaceous.
出处
《矿物岩石地球化学通报》
CAS
CSCD
2001年第4期317-319,共3页
Bulletin of Mineralogy, Petrology and Geochemistry
基金
国家重点基础研究发展规划项目 (G19980 40 80 0 )
国家自然科学基金 ( 4 9772 0 10 7)资助项目
关键词
西藏冈底斯
林子宗火山岩
氩-氩年代学
Gandise in Tibet
Volcanic rock of the Linzizong Group
40Ar/ 39Ar dating
