Chinese Acad Sci, Inst Geol & Geophys, Beijing 100029, Peoples R China
; Chinese Petr Explorat & Dev Acad, Beijing 100083, Peoples R China
; Chinese Acad Sci, Inst High Energy Phys, Beijing 100039, Peoples R China
There are a lot of granite from Xiahe to Lixian along the west Qinling which is of the adakite geochemical feature. The paper reports the SHRIMP dating of Yeliguan and Xiahe granite plutons. The SHRIMP ages are 245 +/- 6 Ma and 238 +/- 4 Ma respectively, belong to early Indosinian period. The adakite is rich of potassium, is classified by high potassium ealc-alkalic series. Geology and geochemical data show that the adakite in the western Qinling was formed in the active plate margin, and was associated with the melting of thicken lower crust in the active crust margin. The dating implicated that the convergent and consuming of palaeotethys was processing at early Indosinian.