Alunite ⁴⁰Ar/³⁹Ar Dating of Gaoshan Deposite, Fujian Province and Its Limitation of the Mineralization Age of Shoushan Stone

Shoushan stone is one of four traditional seal stones in China, which is an epithermal nonmetallic deposit, but the age of its mineralization is unclear. In this paper, the alunite ⁴⁰Ar/³⁹Ar age of Gaoshan Shoushan stone deposite is determined by using the micro area laser heating technology. The plateau age of alunite is 122.56 ± 0.95 Ma, and the corresponding ⁴⁰Ar/³⁶Ar-³⁹Ar/³⁶Ar isochron age is 122.55 ± 0.95 Ma. The recorded time of alunite in Gaoshan mining area represents the ore-forming age of high-quality filling-type dickie of shoushan stone, and it represents that the latest metallogenic age of Shoushan stone is about 122 Ma. In combination with the age (132-135 Ma) of the volcanic rock, from Xiaoxi formation, which is the parent rock of Shoushan stone, it indicates that the metallogenic age of Shoushan stone should be 132-122 Ma.