Abstract: Sabei tin deposits in the eastern Zunghar in Xinjiang occur in the quartz veins of biotite granites and also alkali amphibole-bearing quartz veins of alkali-enriched granites，whose distribution is generally controlled by the NNE- and NE- trending faults in the area.The quartz veins and their mineralization are closely related with the lithological variations in granites in Kalamaili ore deposits zone.The lithology evolves from calc-alkaline，via near-alkali granites，to alkali granites from (N)NW to (S)SE，along with the quartz veins varying from quartz-dominated，via cassiterite-bearing quartz-dominated，to cassiterite-bearing amphibole quartz-dominated.SHRIMP U-Pb zircon dating indicates that the age of the zircon in cassiterite-quartz is （329.2±1.5） Ma，close to the formation time of the Laoyaquan-Hongtujing-Sujiquan biotite granitic batholith; and the age of the zircon in alkaline-enriched granites is （313±2） Ma~（314±5） Ma，in conformity with the active period of post-collisional plutonic rocks (330~310 Ma) in the eastern Junggar.Therefore，the ages of diagenesis and mineralization of Sabei tin deposits correspond respectively to the first (340~330 Ma) and second (300~285 Ma) of the three peak phases of the post-collisional mineralization in the northern Xinjiang Province.This ore formation is of multi-phase type and is not only related to alkali granites but also to biotite granites.

Key words: SHRIMP Zircon U-Pb dating, Cassiterite-bearing quartz vein, Alkali-enriched granite, Sabei tin deposit, Eastern Zunghar