中国东部花岗岩的钾－铀－钍元素地球化学

Geochemistry of K_2O-U-Th Elements of Granites from Eastern China

以吉林、辽宁、河北、河南、山东、安徽、江西、福建、湖北和广东等地为代表的中国东部花岗质岩石的钾－钍－铀元素资料为基础，本文分析和总结了它们的基本变化规律，讨论了地球化学类型、区域分布特点和岩石成因学意义等方面的问题。中国东部花岗岩可被划分为正常、高铀和低铀三种类型，存在南方以正常和高铀型为主、华北以正常和低铀型为主的分布规律，前两类花岗岩的源岩分别为变火成岩和变沉积岩，低铀类型可能衍生于曾经历过表生风化作用的变火成岩、或低成分成熟度的变火成硬砂岩物质。

On the basis of about 350 analytical results of K_2O,Th,U of granites from Jilin,Liaoning,Hebei,Henan,Shandong, Anhui,Jiangxi,Fujian,Hubei and Guangdong province,Eastern China,a general rule of variation of these elements of the granites is summarized,and it is applied to discuss problems of geochemical type ’distributive char- acteristic and petrogenetic significance of the granites。These granites can be divided into three types,e.g.normal,high-U and low-U。A distributive pattern is pointed out that normal and low-U types of granites are dominant in Northern China while normal and high-Utypes are large scale in Southern China。Three metamorphic materials,which are derived from igneous rock,sedimantary rock and weathered igneous rock and/or igneous greywacke of low compositional maturity,are considered respectively as source rocks of the three granites。