Zircon U-Pb ages, geochemistry and isotopic characteristics of the Chu Lai granitic pluton in the Kontum massif, central Vietnam
Nguyen Trung Minh, Nguyen Thi Dung, Doan Dinh Hung, Pham Minh, Yongjae Yu & Pham Trung Hieu
The Chu Lai granite is widespread throughout the northern Kontum massif and is an important key in understanding the evolution of the Kontum region and its vicinity. The study presents new data on geochemistry, zircon U-Pb ages, and Nd-Hf isotopes from the Chu Lai granite which allows to constrain the Paleozoic tectonic evolution of the Kontum massif. The Chu Lai granite contains alumina-rich minerals (garnet and muscovite), is depleted in Ba, Nb, Ta, Sr and Ti but enriched in Rb, Th, U and Pb. These geochemical characteristics indicate a S-type nature of the Chu Lai granite. The zircon ɛHf values vary between −16.7 to −1 and Hf model ages (TDM2) between 1.50 and 2.49 Ga as well as whole rock ɛNd values of −8.3 to −5.8 and Nd model ages (TDM2) between 1.67 and 1.89 Ga. The Hf-Nd isotope data indicate that the Chu Lai granite was derived from partial melting of Paleoproterozoic metasedimentary material. The LA-ICP-MS zircon U-Pb ages range from 445 Ma to 454 Ma, suggesting a crystallization of the Chu Lai granite during the Ordovician-Silurian period.