摘要
五台群是我国早前寒武纪典型地层之一 ,主要出露在山西省五台山地区。经过一百多年来中外学者的研究 ,对五台群的认识取得了重要进展 ,但对其层序的划分和地质年代的归属仍有不同意见。作者在野外地质工作基础上 ,根据高凡亚群、滹沱群底界和侵入五台群岩体 (特别是同构造早期的侵入岩 )等年龄资料 ,认为五台群的顶界年龄大致为 2 5亿年左右 ;根据金刚库组斜长角闪岩的Nd平均模式年龄、侵入金刚库组石佛岩体小马蹄沟处片麻状花岗闪长岩残余锆石的TIMS法年龄和片麻状花岗闪长岩的Nd模式年龄 ,提出五台群的底界年龄为 2 80 0Ma。因而五台群的地质年龄为 2 80 0～ 2 5 0 0Ma ,属新太古代。
Wutai Group distributing in Shanxi Province is one of the typical early Precambrian geological strata in our country. Studied by both Chinese and foreign scholars in the last one hundred years, the great progress was made in Wutai Group. But there are still the different opinions on the division of the succession of strata and geochronology. On basis of the field geological work and the age data of the Gaofan Subgroup, Huto Group bottom boundary and intrusive rock of Wutai Group(especially syntectonic early intrusives), the authors suggest that the top boundary age of Wutai Group is about 2 500 Ma. According to the average Nd model age of the amphibolite of Jingangku Formation, and the remaining zircons TIMS age of the Xiaomatigou gneissic granodiorite and the Nd model age of the gneissic granodiorite invading in the Jingangku Formation, the authors put a suggestion to the 2 800 Ma of the Wutai Group bottom boundary. Because of the geological age is 2 800 ～ 2 500 Ma, Wutai Group belongs to Neoarchean Era.
出处
《地质调查与研究》
2003年第2期72-79,共8页
Geological Survey and Research
基金
国家黄金攻关项目 (90 0 5 1- 0 1)
中国成矿体系与区域评价项目 (K1.4 )
华北地区前寒武纪重大地质矿产问题研究 (2 0 0 10 1)
关键词
五台群
地质年代
顶界年龄
底界年龄
新太古代
Wutai Group
geochronology
the top boundary age of Wutai Group
the bottom boundary age of Wutai Group
