论文部分内容阅读
通过对北祁连西段野牛滩花岗质岩体中花岗闪长岩和黑云母花岗岩的锆石U-Pb测年,获得~(206)Pb/~(238)U表面年龄统计权重平均值为459.6±2.5 Ma,表明其形成于板块俯冲晚期。与之有关的塔儿沟和小柳沟是世界上形成于板块俯冲环境为数不多的大型钨矿床。黑云母花岗岩的锆石U-Pb不一致曲线的下交点年龄为183.1±3.8 Ma可能示意北祁连山地区叠加有燕山期地质事件。
By U-Pb dating of granodiorite and biotite granite in the Ye Niudan granitic rock mass in the western part of North Qilian, the statistical weighted mean age of ~ (206) Pb / ~ (238) U surface ages The value of 459.6 ± 2.5 Ma, indicating that the formation of plate subduction late. The related Targou and Xiaoliuogou are the largest tungsten deposits in the world which are formed in subducted plate tectonics. The dating point of the U-Pb U-Pb curve of the biotite granite is 183.1 ± 3.8 Ma, which may indicate the superimposition of Yanshanian geological events in the North Qilian Mountains.