Abstract:Lithium is an important strategic metal mineral, and spodumene granite pegmatite is an important source of lithium resources. Recently, the spodumene granite pegmatite group has been newly discovered in Chaka Mountain area of the northern margin of Qaidam. This paper determines the mineral formation, evolution and mineralization age of spodumene granite pegmatites through petrography, mineralogy and chronology. The spodumene granite pegmatite has two phases of mineral assemblages. In the early stage, there are coarse-grained spodumene, coarse-grained K-feldspar, coarse-grained muscovite, coarse-grained plagioclase, coarse-grained quartz and coltan, which belong to the product of the melt crystallization stage. The late stage is composed of cookeite, Li-rich mica, wormlike spodumene and fine allomorphic quartz, which is the product of post magmatic hydrothermal metasomatism. Therefore, it can be inferred that there are two stages of lithium mineralization, and the local alteration of early spodumene and the formation of later lithium minerals indicate that there is a process of lithium activation and reprecipitation in the system. The coltan associated with spodumene gives a U-Pb age of 241.0 ± 1.3 Ma, indicating that the melt crystallization age of the spodumene granite pegmatite is the early lithium mineralization age, and the ore body is the product of Indosinian period.