西藏普兰县马攸木金矿床石英的^(40)Ar/^(39)Ar年龄及其地质意义

^(40)Ar-^(39)Ar dating of quartz from gold-bearing quartz veins in the Mayum gold deposit, Burang, Tibet, and its geological significance

对西藏阿里地区马攸木金矿床含金石英脉样品进行40Ar/39Ar快中子活化法测年,其坪年龄为44.08Ma±0.39Ma,等时年龄为44.10Ma±0.20Ma,坪年龄代表石英的形成年龄。测试结果表明,西藏阿里地区可能存在喜马拉雅期金的成矿作用,且喜马拉雅期可能是西藏冈底斯-雅鲁藏布江成矿带形成金矿的主要时期。

Quartz from gold-bearing quartz veins of the Mayum gold deposit in the Ngari area, Tibet, was dated by using the 40Ar/39A fast-neutron activation technique, which gave a plateau age of 44.08±0.39 Ma and an isochron age of 44.10±0.20 Ma.The plateau age represents the age of quartz formation. The analysis suggests that there might occur Himalayan gold mineralization in Ngari, Tibet,and that the Himalayan stage may be the main metallogenic epoch for gold deposits in the western part of the Gangdise-Yarlung Zangbo metallogenic belt.