Abstract:
The Manite area is located in the Animaqing metallogenic belt of East Kunlun. In order to determine the formation time, magma source and tectonic setting of the quartz diorite in this area, the zircon LA-ICP-MS U-Pb dating, isotopic composition and geochemistry have been studied in this paper. The results show that the pluton emplacement time is (206.8±1.7)Ma(MSWK=0.50),belonging to the Late Triassic. The quartz diorite have SiO
2 of 57.17%~68.55%,Na
2O of 3.31%~5.39%, K
2O of 1.52%~3.37%,ALK of 5.19%~7.24% and A/CNK of 0.93~1.25, they are Aluminiums and belong to calc-alkaline rock series. The REE distribution modes show the LREE accumulation and weak negative Eu anomalies. The quartz diorite is characterized by the enrichment of LILEs (Rb,Ba and K) and incompatible elements(U and Th), as well as the depletion of HFSEs (Nb,Ta,Ti and P). Above features show that this rock belongs to high-K calc-alkaline I-type granite. Combined with the geochronological data, geochemical characteristics and the regional tectonic evolution, it's included that this rock has the characteristics of post-collisional magmatism, and the quartz diorite was the product of crustal partial melting after the collision of the East Kunlun block and Bayan Har block.