Abstract: The ophiolitic melange belt was identified in Chabaxia area, Menyuan County of Qinghai Province, along the North Qilian orogenic belt. Its physical composition is complex, and the tectonic blocks involved in the belt include metamorphic peridotite, mafic dyke, metamorphic basic lava, intermediate intrusive rock, metamorphic intermediate acid volcanic rock and exotic strata. The mafic dykes and metamorphic basic lava have the REE distribution patterns which are slightly right-inclined and slightly enriched in LREE. They also show enrichment of LILES such as Ba and U, whereas HFSE such as Nb, Ta, Zr and Ti do not show anomalies. These geochemical characteristics are similar to features of E-MORB. LA-ICP-MS zircon U-Pb dating of alteration gabbro yielded ²⁰⁶Pb/²³⁸U weighted average age of 522.6±9.7Ma. In combination with the previous research results, the authors infer that Chabaxia ophiolite was formed in the tectonic environment of of northern Qilian basin expansion in Early Cambrian. The identification of Chabaxia ophiolite melange suggests that south ophiolite belt of North Qilian orogenic belt expanded and extended southeastward, and thus early ocean basin of North Qilian orogenic belt expanded southeastward.