Archean mantle contributes to the genesis of chromitite in the Palaeozoic Sartohay ophiolite, Asiatic Orogenic Belt, northwestern China

► SHRIMP U-Pb age and Re/Os data further support Sartohay ophiolite was formed in Palaeozoic time. ► Re-Os model ages for the chromitites indicate extraction from the primitive mantle as early as 3.5 Ga. ► The Archean mantle contributed to the genesis of the Paleozoic Sartohay chromitite.