Located in the junction part of the Jinshajiang suture zone and the Ganzi-Litang suture zone, the Yushu melange is a key area to reveal the Paleo-Tethyan tectonics of the northern central Tibetan Plateau. This study presents new geochemical data for the Xiewu basalts of the Yushu melange. These rocks have preserved a record of island arc magmatism on the northern margin of the North Qiangtang block. The basalts belong to calc-alkaline affinities. They are relatively enriched in large-ion lithophile elements and slightly depleted in high field strength elements. Their high MgO, Ni, and Cr values, relatively high La/Sm and low Sm/Yb ratios and positive bulk εNd(t) values suggest that they were derived from the partial melting of a depleted spinel-lherzolite mantle source metasomatized by hydrous fluids. The Xiewu basalts are geochemically similar to island arc basalts. Their eruption was related to initial subduction of the Ganzi-Litang Paleo-Tethyan oceanic plate beneath the North Qiangtang block. Combined with existing data, the authors hold that the Yushu melange converged with the Ganzi-Litang suture zone to the east, rather than with the Jinshajiang suture zone to the southeast. The magma source of the basalts in the Yushu melange was changed from garnet lherzolite to spinel lherzolite during Permian-Triassic period, corresponding to the rifting and spreading processes of the Ganzi-Litang Paleo-Tethyan ocean.