Mineralization of the Tuwu Porphyry Cu Deposit in Eastern Tianshan, NW China: Insights From In Situ Trace Elements of Chlorite and Pyrite

The Tuwu porphyry copper deposit is located on the Dananhu-Haerlik island arc in eastern Tianshan, NW China. Based geology, petrology, and situ trace element studies of pyrite chlorite, we redefined characteristics hydrothermal fluids following three mineralization stages: premineralization stage (stage Ⅰ), metallogenic Ⅱ), superimposed transformation Ⅲ). Pyrite Ⅰ (Py-I) has highest Co/Ni ratios, precipitation crystallization chlorite (Chl-I 2 ) similar rare earth distribution patterns with those volcanic rocks Carboniferous Qieshan (CQ), indicating intense activity. ratios Py-II 1 Ⅱ) tend to decrease over time. Moreover, (REE) Chl-II have LREE enrichment, Eu anomalies , 3 range from positive negative. initial ore-forming fluid was mainly magmatic fluid, late-stage addition meteoric water continuous sulfide precipitation, composition changed, whole system became more oxidizing. Py-III Ⅲ) lowest REE pattern Chl-III characterized by enrichment. shows obvious shear deformation characteristics. results indicate that host experienced intensely reformation. By combining integrating our regional evolution processes propose undergone metamorphic processes. Volcanism Ⅰ) provided space conditions for emplacement body. With plagiogranite main occurred surrounding rocks. After Ⅲ), ductile shearing collisional compression led a reaction, its accumulation along faults formed an ore shoot.