矿床地质2018，Vol.37Issue(3)：502-520,19.DOI:10.16111/j.0258-7106.2018.03.004
贵州泥堡卡林型金矿热液蚀变矿物学研究及其地质意义
Hydrothermal mineralogy of Nibao Carlin-type gold deposit, Guizhou Province and its geological significances
摘要
Abstract
The Nibao gold deposit is a large Carlin-type fault-controlled deposit located in southwestern Guizhou Province of China.The wall rock of the deposit is mainly calcareous-bearing pyroclastic breccias from upper Permian Emeishan Basaltic Formation.Therefore,this deposit is characterized with common low temperature mineral assemblages and Au-bearing minerals of Carlin-type deposits,and some unique hydrothermal minerals.The zoned arsenian pyrite and arsenopyrite are the dominant Au-bearing minerals,and progress from early sedimentary framboidal pyrite (Py 0) and hydrothermally altered dark-pitted sedimentary pyrite (Py Ⅰ) with low As content,which is overgrown by hydrothermal pyrite (Py Ⅱ).These pyrites are in turn overgrown by auriferous middle (Py Ⅲ) and outer (Py Ⅳ) zones of arsenian pyrite with relatively high As and low S and Fe contents.The last generation of pyrite (Py Ⅴ) is associated with stibnite and sphalerite.The elements Ti,P,Cu were derived from the volcanic host-rocks of the Emeishan Basalt Formation and precipitated into minerals such as anatase,apatite,chalcopyrite,tetrahedrite during hydrothermal alteration.Laser Raman spectroscopy studies show the TiO2-bearing mineral that formed in the low temperature condition is anatase rather than rutile.Thus,whether or not the obtained age of rutile by previous researcher could represent the ore-forming age of gold need further study.Contrarily,apatite and sericite are hydrothermal minerals that formed during the main metallogenic stage,and their in-situ dating data could represent the ore-forming age of the Nibao gold deposit.Sulfate minerals such as barite,and gypsum formed in the late stage of the ore-forming process are indicators of a more oxidised setting.Furthermore,isotopic fractionation has resulted in sulfides,such as stibnite,orpiment and realgar,which are co-existed with sulfate minerals,having lower sulfur isotopic compositions than the ore-stage pyrite and arsenopyrite.This study shows that hydrothermal mineralogical studies are important in understanding the mineralization processes related to Carlin-type gold deposits.关键词
地质学/特征热液蚀变矿物/环带状黄铁矿/磷灰石/泥堡金矿Key words
geology/characteristic hydrothermal mineral/zoned pyrite/apatite/Nibao gold deposit分类
天文与地球科学引用本文复制引用
陈懋弘,郭申祥,谢贤洋,马克忠..贵州泥堡卡林型金矿热液蚀变矿物学研究及其地质意义[J].矿床地质,2018,37(3):502-520,19.基金项目
本文受国家自然科学基金面上项目(编号:41572072)、国家重点基础研究发展计划“973”课题(编号:2014CB440902)和中国地质调查局地调项目(编号:DD20160124)联合资助 （编号:41572072）
