Sr and Nd isotope geochemistry of fluorites from the Maoniuping REE deposit, Sichuan Province, China: implications for the source of ore-forming fluids

摘要

Fluorites are one of the main vein minerals in the Maoniuping REE deposit, Sichuan Province, China. This paper anlayzes the Sr and Nd isotopic compositions of fluorites in the orefield. Their (~87Sr/~86Sr)_O and (~143Nd/~44Nd)_O (0.706031-0.706237) and 0.512370-0.512412, respectively) are similar to those of carbonatites (0.706074-0.706149 and 0.512383-0.512406. respectively) and syenites (0.705972-0.706302 and 0.512378-0.512405, respectively) in the orefield and all lie in the narrow range between EM I and EM II in teh diagram of (~87Sr/~86SDr)_i vs. (~1453Nd/~144Nd)_i. In combination with other geological and geochemical data, we suggested that the ore-forming fluids of the Maoniuping REE deposit mainly came from syenite-carbonatite magmas.