Petrogenesis and Geodynamic Significance of the Early Triassic Nanpo Adakitic Pluton of the Luang Prabang-Loei Tectonic Belt (Northwestern Laos) in the East Tethys Domain: Constraints from Zircon U-Pb-Hf Isotope Analyses and Whole-Rock Geochemistry

Researchers have uncovered significant insights into the magmatic and tectonic evolution of the Luang Prabang-Loei Tectonic Belt, part of the East Tethys domain. The study reveals that Early Triassic adakitic plutons, such as the Nanpo pluton in Laos, formed during a critical transition from subduction to continental collision. These adakites exhibit distinct geochemical signatures, including high Sr/Y and (La/Yb)N ratios, indicative of partial melting of thickened lower crust with contributions from mantle-derived magma. Zircon U-Pb-Hf isotope analyses further constrain the emplacement age (247.9–249.0 Ma) and crustal growth processes in the Paleo-Tethys orogenic belt. The findings highlight the importance of magma mixing between crustal and mantle sources during continental crust formation, providing new constraints on the geodynamic history of southeastern Asia.

Li, H., Gan, J., He, Z., Gan, Y., Wang, B., Li, Y., & Jiang, W. (2023). Petrogenesis and Geodynamic Significance of the Early Triassic Nanpo Adakitic Pluton of the Luang Prabang-Loei Tectonic Belt (Northwestern Laos) in the East Tethys Domain: Constraints from Zircon U-Pb-Hf Isotope Analyses and Whole-Rock Geochemistry. Minerals, 13(6), 821. https://doi.org/10.3390/min13060821