高校地质学报2018，Vol.24Issue(2)：200-209,10.DOI:10.16108/j.issn1006-7493.2017090
云南富乐铅锌矿床中铜矿物的矿物学特征及地质意义
Mineralogical Characteristics and Geological Significance of Copper Minerals in Fule Pb-Zn Deposit,Yunnan Province,China
摘要
Abstract
The mineral assemblage in the MVT Pb-Zn deposits is generally simple because the copper minerals of this type of deposit are very rare.As one of the largest MVT deposits in the Sichuan-Yunnan-Guizhou(SYG)Pb-Zn metallogenic domain,the Fule Pb-Zn deposit is hosted in the Permian Yangxin Formation dolostone,which is the youngest ore-bearing strata in the area,and the distance between Pb-Zn ore bodies and the Permian Emeishan basalts is less than 160 m. By means of microscopic, Scanning Electron Microscopy (SEM) and Energy Dispersive Spectrum (EDS) analysis, a great number of copper-bearing minerals were found in the deposit, including chalcopyrite, Zn-tennantite, tetrahedrite and malachite. These minerals occur as banded, vein and irregular, and replace sphalerite or pyrite.The research shows that the droplet chalcopyrite is distributed within sphalerite,implying that both of them were formed at the same mineralization stage. The Zn-tennantite and tetrahedrite, occurring as irregular veins, are cross-cutting the sphalerite grain,or distributed at the edge of the sphalerite,indicating that it was formed later than that of Pb-Zn mineralization.The copper minerals mentioned in this study commonly occur in middle-low temperature hydrothermal deposits,in which the Zn-tennantite is a rare sulfosalts.The appearance of Zn-tennantite and tetrahedrite indicates an oxidizing environment,and malachite is a secondary mineral formed at supergene weathering stage. The paragenetic sequence in the deposit is inferred as follows: pyrite→sphalerite (droplet chalcopyrite)→galena→chalcopyrite→Zn-tennantite→tetrahedrite→malachite. Combined with the geologic and geochemical characteristics of this deposit,it is suggested that there are two possible sources of copper.Early-stage copper was derived mainly from the basement of the Kunyang group and the late-stage copper was likely stemmed from the upper Emeishan basalts,which are different from those of Pb and Zn derived mainly from the Kunyang Group in the deposit.The research provids new geological and geochemical evidence for understanding the genetic relationship between the Emeishan basalts and Pb-Zn mineralization in the SYG district.关键词
富乐铅锌矿/黄铜矿/锌砷黝铜矿/黝铜矿/MVT型矿床Key words
Fule Pb-Zn deposit/chalcopyrite/Zn-tennantite/tetrahedrite/MVT deposits分类
天文与地球科学引用本文复制引用
李珍立,叶霖,黄智龙,周家喜,胡宇思,念红良..云南富乐铅锌矿床中铜矿物的矿物学特征及地质意义[J].高校地质学报,2018,24(2):200-209,10.基金项目
国家重点基金(41430315) （41430315）
973项目(2014CB440900) （2014CB440900）
国家重点研发计划(2017YFC0602502-1)联合资助 （2017YFC0602502-1）
