REE GEOCHEMISTRY OF ROCKS IN LAMASU COPPER DEPOSIT IN NORTHERN XINJING

Lamasu Cu deposit is a typical skarn type in northern Xinjiang. REE patterns of various rocks in the mine are established with the REE geochemical study and REE geochemical behavior of intermediate acidic shallow introssive rock, carbonate rock, skarn and basic dyke is discussed. The rocks are characterized by the similarity of strong negative Eu and weak Ce negative anomly, w (La) n/ w (Sm) n w (Gd) n/ w (Yb) n. The shallow intrussive is characterized by lower w (La) n/ w (Yb) n and wide range of δ(Eu) values, carbonate by higher w (La) n/ w (Yb) n and narrow range of δ(Eu) values, skarn by the values lying in between the former two rocks and the intermediate acidic intrussive by increasement of SiO 2 with decreasement of δ(Eu).