皖西前寒武纪变质岩系地质年代学研究 |
| |
引用本文: | 营俊龙,王扬德,赵溥云,林秀兰,桑宝梁,邢凤鸣,陈跃志.皖西前寒武纪变质岩系地质年代学研究[J].地球化学,1984(2):145-152. |
| |
作者姓名: | 营俊龙 王扬德 赵溥云 林秀兰 桑宝梁 邢凤鸣 陈跃志 |
| |
作者单位: | [1]安徽省地质研究所 [2]北京铀矿地质研究所 |
| |
摘 要: | Isotopic ages of Precambrian metamorphic rocks from western Anhui have beeu determined, giving, a whole-rock Rb-Sr isochron age of 2.7 b.y. and two groups of mineral Rb-Sr isochron ages ranging from 2.3 to 2.2 and 1.8 to 1.4 b.y. respectively. These ages represent the time of cooling of the rocks affected by thermal events. U-Th-Pb ages indicate that the U-Pb isotopic system was disturbed during metamorphism. But Th-Pb, Pb-Pb and whole-rock Rb-Sr ages are relatively concordant while K-At and Rb-Sr ages are all the same. Initial ^87Sr/^86Sr ratios in the metamorphic rocks are within the range of 0.704---0.707.This shows that these rocks contain significant amounts of sialic materials.
|
关 键 词: | 前寒武纪 变质岩 地质年代学 地质特征 |
本文献已被 CNKI 维普 等数据库收录! |
|