U-Pb ages of Kude and Sajia leucogranites in Sajia dome from North Himalaya and their geological implications

Abstract

U-Pb ages of zircon, monazite and xenotime from the Kude and the Sajia leucogranites in the Sajia dome of the North Himalayan tectonic unit are measured using TIMS method. The results show that the magma emplacement ages for the Kude and the Sajia leucogranite are 27.5 f 0.5 and 14.4±0.2 Ma, respectively. Combined with published U-Pb data from the North Himalayan leucogranites, the time-span for the formation of the North Himalayan leucogranites is updated from 27.5 to 10 Ma, instead of previous 15 to 10 Ma. According to the U-Pb ages, the petrogenesis for the North Himalayan leucogranites can be constrained. It is suggested that the North Himalayan leucogranites have variety in their petrogenesis.