According to the content of TiO₂, the authors divide the basalts from the Wushaoling ophiolites into low-Ti basalts (TiO₂=0.55%～0.76%) and high-Ti basalts (TiO₂=1.35%～1.99%). In the discrimination diagrams, the low-Ti basalts sit in the continental arc setting, and the high-Ti basalts fall into the mid-oceanic ridge setting. The high-Ti basalts are part of the Wushaoling ophiolite melanges, derived from depleted mantle, which occur together with the continental arc basalts due to the later tectonic movements. The Wushaoling ophiolite melanges probably formed in the Middle-Late Ordovician in the Laohushan-Maomaoshan back-arc basin of the hemas-microsoft-com:office:smarttags" />North Qilian orogene belt.hemas-microsoft-com:office:office" />