小秦岭东桐峪金矿床稳定同位素地球化学及成矿物质来源  

Stable Isotope Geochemistry and Ore-forming Materialsof the Dongtongyu Gold Deposit in Xiaoqinling Area,China

作　　者：吴晓贵[1] 

机构地区：[1]新疆维吾尔自治区地质矿产勘查开发局第四地质大队,新疆阿勒泰836500

出　　处：《西北地质》2016年第4期91-98,共8页Northwestern Geology

基　　金：全国危机矿山接替资源找矿专项典型矿床及成矿规律总结研究项目(20109903);国家自然科学基金项目(40972066)资助

摘　　要：东桐峪金矿位于小秦岭金矿田中西部,矿体受韧性剪切构造带控制。为了确定矿床成矿流体和成矿金属来源,笔者系统研究了该矿床的3个成矿阶段S、C、H、O同位素组成特征。结果显示12件石英中包裹体水的δDH_2O变化范围为-78.1‰^-42.2‰;12件石英样品中第Ⅰ阶段δ^(18)OH_2O值为9.76‰~13.16‰;Ⅱ阶段δ^(18)OH_2O值为6.30‰~8.10‰;Ⅲ阶段δ^(18)OH_2O值为6.76‰~7.26‰。流体包裹体中CO_2的δ^(13)C值为-1.8‰^-2.5‰。16件硫化物δ^(34)S值为-3.7‰^+8.2‰。H、O、C同位素组成特点表明,水兼有变质水和岩浆水的特征,是太华群基底深熔作用蒸汽相的产物,其运动与长期的糜棱岩带活动有关。成矿流体中C主要来自地幔。S同位素组成特征表明矿石中S来自太华群或深部重熔的岩浆岩。The Dongtongyu gold deposit is located in the middle-west part of Xiaoqinling gold ore field. The ore bodies are controlled by the ductile shear zone. In this paper, the authors systematically studied C, H, O and S isotopic compositions of the three mineralization stages in order to define the source of ore-forming fluids and metals. The 3D values of 12 quartz samples from different stages range from - 78.1‰ to - 42.2‰. The δ18 OH2O values of 12 quartz samples fromthree different stages vary from 9.76‰ to 13.16‰, from 6.30‰to 8.10‰ and from 6.76‰ to 7.26‰, respectively. The δ13C values of CO2 in fluid inclusions change from -1.8‰ to 2.5‰. The ~34S values of 16 sulfides samples in this deposit vary from --3.7‰ to ＋8.2‰. The hydrogen and oxygen isotopic compositions indicate that these ore-forming fluids were mainly sourced from the magmatic water and metamorphic water. The carbon in ore-forming fluid was mainly sourced from mantle materials. Based on the sulfur features, the authors hold that the metals of the Dongtongyu Gold Deposit were derived from Taihua Group or magmatic rocks.

关 键 词：稳定同位素 成矿流体物质来源 东桐峪金矿 

分 类 号：P597[天文地球—地球化学]