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Trace and minor elements in sulfides from the Lengshuikeng Ag–Pb–Zn deposit, South China: A LA–ICP–MS study.

Authors :
Qi, Youqiang
Hu, Ruizhong
Gao, Jianfeng
Leng, Chengbiao
Gao, Wei
Gong, Haotian
Source :
Ore Geology Reviews. Feb2022, Vol. 141, pN.PAG-N.PAG. 1p.
Publication Year :
2022

Abstract

[Display omitted] • The differences in mineral composition were related to temperature, alteration and hydrothermal fluid. • Ag ranges n*103 ∼ n*104 ppm in galena, n*10 ~ n*103 ppm in sphalerite and pyrite. Sphalerite has higher Au and Ag. • Silver occurs as a solid solution in samples with massive textures and as micro-inclusions in alteration samples. • The minor and trace elements are typical characteristics of massive sulfide deposits in the LSKD. Sphalerite, pyrite and galena are common sulfide minerals in Zn–Pb–(Ag) deposits, containing minor and trace elements that can be used to constrain the ore-forming processes. The Lengshuikeng Ag–Pb–Zn deposit (LSKD) is one of the largest silver deposits in China. The mode of silver occurrence in sulfides remains unclear except for individual silver minerals. In this study, we analyzed the minor and trace element contents of sulfide minerals from massive, vein, and veinlet-disseminated ores by in-situ laser ablation–inductively coupled plasma–mass spectrometry (LA–ICP–MS). The elemental compositions of sulfide minerals are variable. Combining petrographic observations and previous studies, we suggest that the sulfide minerals from two types of mineralization (porphyry and strata-bound types) were formed in a same hydrothermal system, and their content of minor and trace elements mainly is influenced by temperature, alteration of wall rocks and composition change of hydrothermal fluid. The Ag content in galena ranges n*103 ∼ n*104 ppm, whereas that in both sphalerite and pyrite ranges from n*10 ∼ n*103 ppm. Except for galena, a higher content of gold (mean = 0.76 ppm) and silver (mean = 151 ppm) occurs in sphalerite compared with the content of gold (mean = 0.26 ppm) and silver (mean = 69.9 ppm) in pyrite. Generally, altered samples display higher Ag and Au contents in pyrite and sphalerite. Silver occurs in the form of a solid solution in sulfides from samples with massive textures, and as micro-inclusions in sulfides from altered samples. The contents of minor and trace elements (e.g. Cd and In) and their ratios (Ga/In, Zn/Cd and Cd/Fe) are not always sensitive to the temperature and processes of deposit formation. We suggest that sulfides from samples with massive texture and limited alteration are suitable for determining the genetic type of the deposit. Our results show that the hydrothermal fluid is a magmatic fluid related to porphyry granite in the LSKD. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
01691368
Volume :
141
Database :
Academic Search Index
Journal :
Ore Geology Reviews
Publication Type :
Academic Journal
Accession number :
155057629
Full Text :
https://doi.org/10.1016/j.oregeorev.2021.104663