Abstract: Quartz vein type gold deposit is one of the most important gold deposit types in the Dayaoshan area, Guangxi Province.
However, there has been no high precision age data to constrain its mineralization epoch. This paper firstly used muscovite
39Ar/40Ar dating to constrain the age of Shangmushui quartz vein type gold deposit in the southern Dayaoshan area from Cangwu
County, Guangxi Province. The study yielded a plateau age of 432.6 ± 3.2 Ma, an isochron age of 428.2 ± 7.2 Ma, and an inverseisochron
age of 425.3 ± 6.6 Ma, indicating its mineralization epoch is Caledonian. These new data further demonstrate that the
Caledonian is the main mineralogenetic epoch in the Gulong-Xiaying ore-forming area from the southern Dayaoshan area.
Except for the Caledonian granitoids related porphyry-skarn tungsten polymetallic mineralization, there are quartz vein type
gold deposits. Meanwhile, the timing of Liucen-Taohua-Gupao gold ore field along the regional Dali fault is not clear and the
oreforming age will need to be constrained by high precision clating data in the future.

Key words: muscovite 39Ar/40Ar dating, caledonian, quartz vein type gold deposit, Dayaoshan uplift, Shangmushui from Cangwu
County, Guangxi