 The fact that the YZSZ separates two continental terrane suggests that it could have been an intraoceanic island arc in the past, locating in between the Asian continental margin (Lhasa terrane) and the Indian continental margin (Indian superterrane) before collision occurred.Vocanic rocks in the Zedong terrane, which belongs to the YZSZ, has high K2O content and are classified as shoshonites.Shoshonites are potassium-rich basaltic andesite which are commonly found in modern intraoceanic arc settings.