A study of metallic sulfides, quartz REE composition characteristics and genesis of the Mengya’a lead-zinc deposit

Abstract：No research results of RRE geochemistry have so far been reported since the discovery of the Mengya’a Pb-Zn deposit. In this paper, the REE compositions of metallic sulfides and hydrothermal quartz from this ore deposit were determined by ICP-MS. Studies show that pyrrhotite, chalcopyrite, sphalerite and galena are somewhat different in REE amount, but they all have the distribution patterns of rightly-oblique LREE enrichment type. According to the Eu anomaly, these metallic sulfides can be divided into 3 groups, and the Eu anomalies are mainly caused by the transformation of physical and chemical environment in the ore-forming process and the mass crystallization of calcite. There also are differences of REE amount in 4 quartz samples due to their difference in crystallization time and temperature, and their distribution patterns are also of the rightly-oblique LREE enrichment type. Meanwhile, the quartzes formed at different stages have their strong positive or negative Eu anomalies separately, which is attributed to the addition of later meteoric water and the formation of lots of calcites.