中文摘要：

对雅鲁藏布江成矿带西段松托嘎花岗斑岩中黑云母样品进行^40Ar/^39Ar快中子活化法测年,其坪年龄为19.67 Ma±0.52 Ma和15.66 Ma±0.31 Ma,等时年龄为19.84 Ma±0.40 Ma和14.29 Ma±0.29 Ma。测试结果及区域研究表明,冈底斯—雅鲁藏布江成矿带存在晚喜马拉雅期的岩浆活动,并可能为这一地区的铜金矿化提供热源和物源。

英文摘要：

Biotite from the granite-porphyry of the Mayoumu area in the All region of weatern Tibet,were analysed by the ^10At/^39 Ar fast-neutron activation dating technique, which revealed a well-defined plateau age of 19.67 Ma±0.52 Ma and 15.66 Ma±0.31 Ma and an isochron age of 19.84 Ma±0.40 Ma and 14. 29 Ma±0. 29 Ma. Combined with the geological features,it is concluded that there existed amagmatic eruption process in the Gangdese -Yalu Tsangpo （Yaluzangbu） mineralization belt at the late Himalayan stage. During this stage,magmatic activity provided hot sources and some metallic element for mineralization of gold and copper in this area.