Abstract:In order to provide constraints for the Miocene tectonic evolution and deep dynamic process in the SE Pamir area, the age of the intrusive rocks in the Reskam area is redetermined and the petrogenesis and magmatic processes are discussed.Methods: Combined with field work and microscope observation, analysis of the LA- MC- ICP- MS zircon U- Pb isotopic dating, XRF major elements, ICP- MS trace elements, MC- ICP- MS Sr—Nd isotopes, LA- MC- ICPMS zircon Lu—Hf isotopes are carried out.Results: Zircon LA- MC- ICP- MS U- Pb dating results show that these magmatic rocks were emplaced at Miocene (12. 0 ± 0. 3 Ma). Geochemically, they have high SiO2 (72. 14% ~ 74. 35%) and high K2O (3. 78% ~ 5. 25%) contents, with low MgO (0. 13% ~ 0. 50%) and Mg# value (18 ~ 35). They exhibit high Sr (363×10-6~754 ×10-6), low Y (3. 41×10-6 ~ 16. 4 ×10-6) and Yb (0. 327×10-6 ~ 0. 903 ×10-6), thus high Sr/Y (27 ~ 188) and (La/Yb)N (18. 95 ~ 210) ratios, in keeping with the typical adakites. In terms of isotopes, they have significantly enriched in situ zircon εHf(t) (-10. 1 ~ -5. 4) and whole-rock εNd(t)( -8. 33 ~ -6. 39 ) values.Conclusions: The Reskam monzogranite was formed in the Miocene (~ 12 Ma) and has the characteristics of Adakite. The continuous subduction of the Indian plate significantly thickened the crust in the Pamir area. At around 12 Ma, due to the tectonic transformation of the Karakoram fault, the local detachment of the thickened lithospheric mantle in the Pamir area resulted in tectonic extension, triggering the upwelling of the asthenosphere and partial melting of the thickened ancient lower crust.