Sm-Nd isotope study and dating on Honguleleng ophiolite in Xinjiang, China

A study of the Sm-Nd isotope composition of Honguleleng ophiolite in Xinjia ng, China, isochron age ((626 +/- 25) Ma),epsilon(Nd)(t) = 8.40, and its mo del age ( T-DM(Nd)) in the range of 1 180-1 208 Ma, indicates that the ophi olite was formed in the late stage of the Upper Sinian. In combination with its facies association, petrochemistry, REE patterns, trace elements and a ssociated chromites orebodies, it is believed that the Honguleleng ophiolit ic magma derived from the LREE-enriched, self-depleted mantle source and fo rmed at paleo-ocean ridge. This ophiolite is a relic of an oceanic crust wi thin the collision zone.