Options
Zn, Fe and S isotope fractionation in a large hydrothermal system
Date Issued
2012-07-01
Date Available
2012-10-16T13:44:12Z
Abstract
The genesis of hydrothermal ore deposits is of crucial economic importance. This study investigates the extent, causes and consequences of zinc and iron isotope fractionation in a large hydrothermal system at the world-class Navan Zn–Pb orebody, Ireland. Large variations in Zn, Fe and S isotope compositions have been measured in microdrilled sphalerite (ZnS) at the millimetre scale. d66Zn and d56Fe display a well-defined positive correlation and both also correlate with d34S. These relationships represent the combined effects of kinetic Zn and Fe isotope fractionation during sphalerite precipitation, and S isotope
variation through mixing of hot, metal-rich hydrothermal fluids and cool, bacteriogenic sulfide-bearing brines. Combined with S isotope data, d56Fe and d66Zn data on mine concentrates confirm that hydrothermal sulfide is a minor component of the overall deposit signature. Our data suggest that incoming pulses of metal-rich hydrothermal fluid triggered sulfide mineralisation, and that rapid precipitation of sphalerite from hydrothermal fluids will lead to strong kinetic fractionation of Zn and Fe isotopes at very short time and length scales, thereby limiting the use of Fe and Zn isotopes as exploration tools within deposits, but revealing the possibility of detecting new deposits from isotopically heavy Zn–Fe geochemical halos.
Sponsorship
Science Foundation Ireland
Type of Material
Journal Article
Publisher
Elsevier
Journal
Geochimica et Cosmochimica Acta
Volume
88
Start Page
183
End Page
198
Copyright (Published Version)
2012 Elsevier Ltd
Subject – LCSH
Zinc--Isotopes
Iron--Isotopes
Sulfur--Isotopes
Hydrothermal deposits--Ireland
Language
English
Status of Item
Peer reviewed
This item is made available under a Creative Commons License
Owning collection
Scopus© citations
116
Acquisition Date
Mar 28, 2024
Mar 28, 2024
Views
2405
Last Week
3
3
Last Month
4
4
Acquisition Date
Mar 28, 2024
Mar 28, 2024
Downloads
1364
Last Week
7
7
Last Month
24
24
Acquisition Date
Mar 28, 2024
Mar 28, 2024