| Abstract:The Tiegelongnan porphyry-epithermal Cu (Au) deposit is one of the most important deposits in the Bangongco-Nujiang metallogenic belt. Pyrite is widely developed in the Tiegelongnan. The trace element, rare earth element and S isotope analysis of pyrite were carried out in this research. According to the occurrence characteristics, three types of pyrite are revealed including pyrite-1, pyrite-2 related to epithermal mineralization, and pyrite-3 related to porphyry mineralization. Pyrite-1 has the lowest content of Au, Ag, Cu, Pb, Zn and Bi, while pyrite-2 has the highest content of Au, Ag, Cu, Pb, Zn and Bi. The correlation between Cu and Ni, Ag and Cu, Cu and Pb, Ag and Pb, Pb and Zn can be used to distinguish between pyrite-2 and pyrite-3. The value δ34S for pyrite-1 (1.9 ‰) is the highest in the three types of pyrite; The δ34S values for pyrite-2 and pyrite-3 are between -4.5 ‰ and 0.3 ‰. Pyrite is rich in LREE and depleted HREE, and has a "right tilt" pattern of rare earth distribution. The REE differentiation of pyrite in the shallow (200-450 m) is relatively large with positive Eu anomaly, while the REE differentiation of pyrite in the deep (700-1000 m) is small with negative Eu anomaly. The migration direction of sulfur-containing hydrothermal solution in Tiegelongnan deposit is horizontally from ZK1604 to the East, and vertically from 230-250 m of ZK1604 to the deep and lateral. The high content of Cu, Au, Ag in pyrite and the positive correlation between Ag and Cu, Pb and Zn, Cu and Pb, Ag and Pb are important indicators of epithermal mineralization, while the negative correlation between Cu and Ni in pyrite is an indicator of porphyry mineralization. |
