Origin of fluids in the Hetaoping Pb-Zn deposit, Baoshan-Narong-Dongzhi block metallogenic belt, Yunnan Province, SW China

摘要: Abstract The Hetaoping skarn type Pb–Zn deposit is located in the Baoshan–Narong–Dongzhi block metallogenic belt (BND belt), a between Tengchong terrane and Lanping basin. hosted by marble of upper Cambrian Formation there are no outcrops plutonic rocks present. This one two large deposits recently discovered BND belt. high Mn skarn. Four types fluid inclusions were recognized quartz from deposit: vapor-rich (Type I), liquid-rich II), pure vapor III), IV). coexistence Type I III Stage (pre-ore stage) II (main ore shows evidence boiling. Quartz-hosted (Stage II) display homogenization temperatures salinities (134–315 °C; 3.7–18.6 wt% NaCl equivalent) but calcite-hosted (post-ore record lower (85–214 °C; 0.5–5.4 wt% equivalent). These data suggest possible mixing primary magmatic water meteoric water. Based on chromatography data, contain abundant CO2 O2 subordinate CO, CH4 C2H2 + C2H4, suggesting an oxidizing environment. their Na/K Cl/SO4 ratios, fluids contained similar to volcanic spring waters. low ratios (0.40–1.34) ore-forming may have resulted interaction with deep alkaline intermediate-acid intrusion. Hydrogen oxygen isotope determinations different stages show δ18O δD values relative VSMOW (−4.3‰ 2.3‰; −109‰ −91‰), indicating that diluted external sources as system cooled. Overall, geological geochemical interpretations distal manganese related concealed intrusions.