摘要
小秦岭金矿田位于华北克拉通南缘,目前探明金储量611 t。前人对该区金矿床做了大量科研工作,但区内金矿的成矿地质背景与成矿物质来源仍存在较大的争议。笔者以小秦岭金矿田南中矿带杨砦峪、樊岔金矿床S60矿脉中黄铁矿为研究对象,通过细致的野外观察与镜下鉴定,将黄铁矿从早到晚分为3个世代,并对不同世代的黄铁矿进行LA-ICP-MS微量元素分析,取得认识如下:不同世代黄铁矿中Au、Ag、Te、As、Co、Ni等微量元素的含量及其分布特征具有较显著的差异性,各个世代黄铁矿中As的含量均很低,暗示该区金矿床的形成与As无关;第2世代黄铁矿中Au与Te尤为富集且两者存在显著和稳定的线性正相关关系,指示该世代为金矿床形成重要阶段,并且Te元素在成矿过程中对Au的搬运、富集、沉淀等过程具有重要作用;S60矿脉中普遍发育Te-Au-Ag矿物,并且黄铁矿中呈现低As、高Te特征,暗示小秦岭金矿床的成矿流体、成矿物质可能来自深部岩浆的脱挥发分或地幔脱气作用,小秦岭地区成矿地质背景与早白垩世华北克拉通破坏有关。
Located in the southern margin of the North China Craton,the Xiaoqinling gold field has a proven gold reserve of over 611t.Although most gold deposits have been extensively studied,issues related to the metallogenic geological background and the source of the ore materials remain debated.This paper conduct further studies on the Yangzhaiyu-Fancha S60 vein of sothern-medium ore belt from Xiaoqinling gold field.Three generations of(PyⅠ,PyⅡ,PyⅢ)were identified according to detailed field investigation and microscopic identification.We presents a study of the distribution characteristics of trace elements in gold-bearing pyrite from different generation,The results show that the contents and trace element distribution characteristics of Au,Ag,Te,As,Co,Ni from different generation assum significant difference,the content of pyrite from different generation is lightly lower,and plays an insignificant role in gold mineralization;There is prominently positive correlation relationship between Au and Te in the second generation and the contents of Au,Te are relatively higher,it shows that the second generation is important for gold mineralization and the Te play an important role in transfer enrichment and precipitation of gold.An intimate Te-Au-Ag association has been widely noticed in widespread gold mineralization in Xiaoqinling gold district,and low-As,high-Te in pyrite,suggesting that the ore-forming materials and ore-forming fluids of the gold deposits may have come from the deep magma devolatilization or mantle degassing,the geogical background of the gold deposit mainly due to the destruction of the North China Craton.
作者
王立峰
薛志强
王振强
王鹏飞
张苏坤
孙保花
王社全
杨智超
张鹏
WANG Lifeng;XUE Zhiqiang;WANG Zhenqiang;WANG Pengfei;ZHANG Sukun;SUN Baohua;WANG Shequan;YANG Zhichao;ZHANG Peng(Henan First Geology and Mineral Survey Institute Co.,Ltd,Luoyang 471000,Henan,China;Key Laboratory of Gold and SilverPolymetallic Mineralization Series and Deep Prediction in Henan Provvince,Luoyang 471000,Henan,China;Shaanxi Mineral Resources and Geological Survey Center,Xi’an 710068,Shaanxi,China)
出处
《西北地质》
CAS
CSCD
北大核心
2024年第5期74-87,共14页
Northwestern Geology
基金
河南省自然资源科研项目“小秦岭金矿田南中矿带超深部流体蚀变特征与金成矿机理研究”(豫自然资函2022-7)
河南省财政项目“河南省灵宝市小秦岭金矿田南中矿带深部探测”(豫自然资发[2020]18号)
“小秦岭3500 m深钻岩心红外光谱特征及蚀变分带研究”(豫地矿青科创[2021]1号)联合资助。
