摘要
粤西云开前寒武纪基底的麻粒岩、紫苏花岗闪长岩和紫苏闪长岩的放射性元素分布具有明显的规律，Ｋ／Ｒｂ比值分别为１１７～２０２，９４～１２９，７８～８９，Ｔｈ／Ｕ比值分别为１５～３０，１１～２０，２５～７８，Ｕ的含量范围分别为０．５×１０－６～０．９９×１０－６，１．２５×１０－６～１．６９×１０－６，１．６５×１０－６～５．３７×１０－６．这种分布规律反映了在低ＸＨ２Ｏ、高ＣＯ２流体参与下麻粒岩的熔融、紫苏花岗质岩浆形成。
The radioactive element distribution in the granulites and charnockites of the Precambrian basement of Yunkai,Western Guangdong,has been determined.The K/Rb ratios,showing a large spread with majority of the values falling within the normal field (K/Rb<300),are respectively 117～202,94～129,25～78.All of the Th/U ratios are greater than those of conventional normal crustal (Th/U=3.8).Uranium content ranges of these rocks are respectively 0.5×10 -6 ～0.99×10 -6 ,1.25×10 -6 ～1.69×10 -6 ,1.65×10 -6 ～5.37×10 -6 .The distribution of the radioactive element in the rocks reflects the process in which granulites melt under low X H 2O accompanying CO 2 condition to form charnockitic magma,and the concentration of relict phases and accessory minerals,such as apatite and zircon.
出处
《地球科学（中国地质大学学报）》
CSCD
北大核心
1996年第5期529-535,共7页
Earth Science-Journal of China University of Geosciences
基金
地质矿产部八五攻关项目
地质矿产部壳幔体系组成
物质交换及动力学开放研究实验室基金
关键词
放射性元素
麻粒岩
紫苏花岗岩
前寒武纪
radioactive element
granulite
charnockite
Precambrian
Yunkai
Western Guangdong.
