滇西云龙锡矿流体包裹体及稳定同位素研究

Fluid Inclusion and Stable Isotope Study on the Yunlong Tin Deposit,Western Yunnan, China

对云龙锡矿流体包裹体及氢、氧同位素的研究表明 ,该矿床至少存在两个矿化阶段 :早期的高温 (≥40 0℃ )及晚期的中—高温 (30 0～ 40 0℃ )矿化阶段。早期的矿化流体的δ1 8OH2 O(7.7‰～ 9.0‰ )和δDH2 O(- 5 8‰～ - 43‰ )值相对较高 ,主要是由岩浆水或 和变质水组成 ;晚期由于有大量演化了的大气降水的加入 ,使流体的δ1 8OH2 O值 ,特别是δDH2 O 值降低。在此期间 ,大气降水与岩浆水或 和变质水不同比例的混合 ,使流体的盐度产生不同程度的波动 ,并在石英中形成了不同类型的流体包裹体。

Based on fluid inclusion and stable isotope studies of the Yunlong tin deposit, a two-stage mineralization model is suggested, i.e., the earlier high temperature (≥400℃) and the later middle to high temperature (300～400℃) stages. The hydrothermal fluids of the earlier stage had higher δ 18O H 2O (7.7‰ to 9.0‰) and δD H 2O(-58‰ to -43‰) values, which was thought to be magmatic and/or metamorphic waters. Substantial evolved meteoric waters may have mixed with the ore-forming fluids during the later stage, which caused a dramatic decrease of δ 18O H 2O and δD H 2O values of the fluids. Due to various degrees of mixing between the evolved meteoric and magmatic and/or metamorphic waters, different types of fluid inclusions were formed in quartz during this stage.