The Altay orogenic belt (AOB) is an important metallogenic belts in China，situated in the middle part of the Central Asian Orogenic Belt (CAOB). Many economic deposits located in the southern margin of the AOB, e.g. Kaktal Pb-Zn deposit, Mengku iron deposit, Abagong iron deposit, Tiemuerte Pb-Zn deposit, Keyinbulak Cu-Zn deposit, etc., are hosted in the Kangbutiebao Formation stratum comprising low grade metamorphosed volcanic rocks. SHRIMP zircon U-Pb method yields a 412.6±3.5Ma（MSWD=1.4）age, representing the eruption age of the matarhyolites in the Abagong iron deposit. It indicates that the volcanic rocks in the Kangbutiebao Formation crystallized in early Devonian, suggesting an active continental margin setting during this time.