The Wanbaogou Group is located on the southern margin of the Qaidam block and along the middle segment of the East Kunlun orogenic belt. It consists of effusive basaltic lavas, terrigenous and volcaniclastic rocks, and limestones. The Wanbaogou basalts can be divided into two groups:high-Ti (HT) alkaline and low-Ti (LT) tholeiitic basalts. The former shows high Ti/Y ratios (502~660), Nb/Y ratios (0.8~1.6) and TiO₂ values (2.76%~4.97%), similar to features of OIB. The latter has relatively low Ti/Y ratios (383~439), Nb/Y ratios (0.3~0.4) and TiO₂ values (1.80%~2.49%), which resembles E-MORB. Zircon SIMS analyses indicate that the Wanbaogou basalts were formed in the Neoproterozoic (762±2 Ma). The field occurrence and geochemical characteristics suggest that the Wanbaogou basalts were formed in a continental rift or an initial oceanic basin environment, and represented the peak stage of the Rodinia breakup.