Subduction-modified mantle-derived Triassic high-Mg andesites in the Sanjiang Tethys, eastern Tibet

Andesites in the Yangla district of the Sanjiang Tethys, eastern Tibet, are characterized by relatively high MgO and with rich large-ion lithophile elements (LILEs), indicating similarities to typical high-Mg andesites formed in continental collisional zones. Zircon U-Pb age of 232 ± 1 Ma for these andesites shows that they occurred synchronously with the regionally widespread late Middle Triassic granitoids and bimodal volcanic rocks. Primitive...