新疆西准噶尔提依尔金矿床氢、氧、硫同位素地球化学研究

Hydrogen,oxygen and sulfur isotope geochemical characteristics of the Tiyier gold deposit in West Junggar,Xinjiang

提依尔金矿位于西准噶尔造山带达拉布特深大断裂北部,金矿化主要呈细脉浸染状、网脉状赋存于安山玢岩中,具有全岩矿化特征。依据矿脉的穿插关系和矿物组合特征,成矿过程经历了石英—钾长石阶段、石英—黄铁矿阶段、自然金—石英—硫化物阶段和石英—碳酸盐阶段。矿脉中石英δ^(18)O_(SMOW)介于16.5‰~18.2‰,δ^(18)O值为7.06‰~10.08‰,δD值为-88.9‰^-76.0‰,其中两件矿化晚阶段石英δ^(18)O分别为-0.69‰和-0.3‰。黄铁矿和毒砂的硫同位素组成δ^(34)S为-1.2‰^+1.7‰。研究结果表明:提依尔金矿床主成矿期成矿流体以岩浆热水为主体,晚期有大气降水的加入,成矿流体中的硫来源于深部岩浆或地幔。

Tiyier gold deposit is located at the north of Dalabute deep fault in western Junggar Orogen,.Gold mineralization, which mainly occurs as veinlet-disseminated and massive, is widely distributed within andesitic porphyrite rocks. Based on cross-cutting relationship and mineral assemblages of ore veins, it show that the ore-forming process underwent four stages as follows：quartz-potassium feldspar stage（Ⅰ）, quartz-pyrite stage（Ⅱ）, gold-quartz-sulfide stage（Ⅲ）, and quartz-carbonatite stage（Ⅳ）. The results show that quartz inclusions δ18OSMOW of early and major ore-forming stage vary from 16.5‰~18.2‰,δ18O of quartz-balance water range from7.06‰~10.08‰, δD range from -88.9‰^-76.0‰; δ18O of two late mineralization stage samples are -0.69‰ and 0.3‰ respectively. δ34S of pyrite and arsenopyrite from gold bearing ore vary from -1.2‰~＋1.7‰. The results indicate that the Ore-forming fluid of Ⅰ-Ⅲ stage is mainly derived from magma, with part of meteoric water, and the last stage was mixed with atmospheric water., which indicate the sulfur in the fluids was derived from deep-seated magma or mantle.