The multiple sulfur isotope architecture of the Golden Mile and Mount Charlotte deposits, Western Australia

Marcelo Godefroy-Rodríguez, Steffen Hagemann, Crystal LaFlamme, Marco Fiorentini

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2 Citations (Scopus)

Abstract

The Golden Mile and Mount Charlotte deposits in the Kalgoorlie Terrane, Western Australia, display three main mineralization styles: Fimiston, comprised of interconnected shear zones associated with ankerite-pyrite ± hematite- ± magnetite-gold-telluride alteration; Oroya, made up of breccia bodies with V-muscovite-ankerite-pyrite ± pyrrhotite-gold-telluride alteration; and Mount Charlotte, which consists of vein arrays with symmetrical ankerite-sericite-albite-pyrite ± pyrrhotite ± gold alteration. Pyrite is in equilibrium with gold in all three mineralization styles and has been selected as a proxy to record the sulfur source of the mineralizing fluids as well as the nature of the hydrothermal processes. The δ34S, Δ33S, and Δ36S analyses on pyrite grains from the different mineralization styles, including oxidized and reduced sulfide-oxide assemblages, reveal (1) a large variation in δ34S (from − 12.6 to + 23.5‰), and (2) a previously unrecognized occurrence of anomalous Δ33S and Δ36S signatures (from − 1.0 to + 1.1‰ and from − 2.3 to + 0.9‰, respectively). It is argued that the mineralizing fluids that formed the Golden Mile and Mount Charlotte deposits record mixing among three components: mantle sulfur, oxidized seawater sulfur (e.g., SO4), and reduced elemental sulfur (e.g., S8). Petrographic evidence in conjunction with Δ33S and Δ36S data suggest that MIF-S was acquired during the deposition of shales and basalts present in the Kalgoorlie Terrane and later mixed with mantle-derived sulfur during the mineralization events. The negative δ34S values that predominate in Fimiston style mineralization are consistent with a prevalence of oxidized fluids during the ore-forming process, as reflected by the presence of hematite-pyrite-magnetite-gold assemblages. Conversely, the positive δ34S values that dominate in the Mt Charlotte and Oroya mineralization styles reflect a reducing environment, as reflected by the presence of pyrite-pyrrhotite-gold assemblages.

Original languageEnglish
JournalMineralium Deposita
DOIs
Publication statusE-pub ahead of print - 18 Sep 2018

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Sulfur Isotopes
sulfur isotopes
sulfur isotope
pyrites
pyrite
Gold
Deposits
deposits
Sulfur
gold
mineralization
sulfur
ankerite
pyrrhotite
Ferrosoferric Oxide
telluride
tellurides
hematite
magnetite
Fluids

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@article{5b6a8d1cad784adeae96545445b8f445,
title = "The multiple sulfur isotope architecture of the Golden Mile and Mount Charlotte deposits, Western Australia",
abstract = "The Golden Mile and Mount Charlotte deposits in the Kalgoorlie Terrane, Western Australia, display three main mineralization styles: Fimiston, comprised of interconnected shear zones associated with ankerite-pyrite ± hematite- ± magnetite-gold-telluride alteration; Oroya, made up of breccia bodies with V-muscovite-ankerite-pyrite ± pyrrhotite-gold-telluride alteration; and Mount Charlotte, which consists of vein arrays with symmetrical ankerite-sericite-albite-pyrite ± pyrrhotite ± gold alteration. Pyrite is in equilibrium with gold in all three mineralization styles and has been selected as a proxy to record the sulfur source of the mineralizing fluids as well as the nature of the hydrothermal processes. The δ34S, Δ33S, and Δ36S analyses on pyrite grains from the different mineralization styles, including oxidized and reduced sulfide-oxide assemblages, reveal (1) a large variation in δ34S (from − 12.6 to + 23.5‰), and (2) a previously unrecognized occurrence of anomalous Δ33S and Δ36S signatures (from − 1.0 to + 1.1‰ and from − 2.3 to + 0.9‰, respectively). It is argued that the mineralizing fluids that formed the Golden Mile and Mount Charlotte deposits record mixing among three components: mantle sulfur, oxidized seawater sulfur (e.g., SO4), and reduced elemental sulfur (e.g., S8). Petrographic evidence in conjunction with Δ33S and Δ36S data suggest that MIF-S was acquired during the deposition of shales and basalts present in the Kalgoorlie Terrane and later mixed with mantle-derived sulfur during the mineralization events. The negative δ34S values that predominate in Fimiston style mineralization are consistent with a prevalence of oxidized fluids during the ore-forming process, as reflected by the presence of hematite-pyrite-magnetite-gold assemblages. Conversely, the positive δ34S values that dominate in the Mt Charlotte and Oroya mineralization styles reflect a reducing environment, as reflected by the presence of pyrite-pyrrhotite-gold assemblages.",
keywords = "Archean, Gold, Mass independent fractionation, Orogenic, Sulfur isotopes",
author = "Marcelo Godefroy-Rodr{\'i}guez and Steffen Hagemann and Crystal LaFlamme and Marco Fiorentini",
year = "2018",
month = "9",
day = "18",
doi = "10.1007/s00126-018-0828-y",
language = "English",
journal = "Mineralium Deposita: international journal of geology, mineralogy, and geochemistry of mineral deposits",
issn = "0026-4598",
publisher = "Springer-Verlag London Ltd.",

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T1 - The multiple sulfur isotope architecture of the Golden Mile and Mount Charlotte deposits, Western Australia

AU - Godefroy-Rodríguez, Marcelo

AU - Hagemann, Steffen

AU - LaFlamme, Crystal

AU - Fiorentini, Marco

PY - 2018/9/18

Y1 - 2018/9/18

N2 - The Golden Mile and Mount Charlotte deposits in the Kalgoorlie Terrane, Western Australia, display three main mineralization styles: Fimiston, comprised of interconnected shear zones associated with ankerite-pyrite ± hematite- ± magnetite-gold-telluride alteration; Oroya, made up of breccia bodies with V-muscovite-ankerite-pyrite ± pyrrhotite-gold-telluride alteration; and Mount Charlotte, which consists of vein arrays with symmetrical ankerite-sericite-albite-pyrite ± pyrrhotite ± gold alteration. Pyrite is in equilibrium with gold in all three mineralization styles and has been selected as a proxy to record the sulfur source of the mineralizing fluids as well as the nature of the hydrothermal processes. The δ34S, Δ33S, and Δ36S analyses on pyrite grains from the different mineralization styles, including oxidized and reduced sulfide-oxide assemblages, reveal (1) a large variation in δ34S (from − 12.6 to + 23.5‰), and (2) a previously unrecognized occurrence of anomalous Δ33S and Δ36S signatures (from − 1.0 to + 1.1‰ and from − 2.3 to + 0.9‰, respectively). It is argued that the mineralizing fluids that formed the Golden Mile and Mount Charlotte deposits record mixing among three components: mantle sulfur, oxidized seawater sulfur (e.g., SO4), and reduced elemental sulfur (e.g., S8). Petrographic evidence in conjunction with Δ33S and Δ36S data suggest that MIF-S was acquired during the deposition of shales and basalts present in the Kalgoorlie Terrane and later mixed with mantle-derived sulfur during the mineralization events. The negative δ34S values that predominate in Fimiston style mineralization are consistent with a prevalence of oxidized fluids during the ore-forming process, as reflected by the presence of hematite-pyrite-magnetite-gold assemblages. Conversely, the positive δ34S values that dominate in the Mt Charlotte and Oroya mineralization styles reflect a reducing environment, as reflected by the presence of pyrite-pyrrhotite-gold assemblages.

AB - The Golden Mile and Mount Charlotte deposits in the Kalgoorlie Terrane, Western Australia, display three main mineralization styles: Fimiston, comprised of interconnected shear zones associated with ankerite-pyrite ± hematite- ± magnetite-gold-telluride alteration; Oroya, made up of breccia bodies with V-muscovite-ankerite-pyrite ± pyrrhotite-gold-telluride alteration; and Mount Charlotte, which consists of vein arrays with symmetrical ankerite-sericite-albite-pyrite ± pyrrhotite ± gold alteration. Pyrite is in equilibrium with gold in all three mineralization styles and has been selected as a proxy to record the sulfur source of the mineralizing fluids as well as the nature of the hydrothermal processes. The δ34S, Δ33S, and Δ36S analyses on pyrite grains from the different mineralization styles, including oxidized and reduced sulfide-oxide assemblages, reveal (1) a large variation in δ34S (from − 12.6 to + 23.5‰), and (2) a previously unrecognized occurrence of anomalous Δ33S and Δ36S signatures (from − 1.0 to + 1.1‰ and from − 2.3 to + 0.9‰, respectively). It is argued that the mineralizing fluids that formed the Golden Mile and Mount Charlotte deposits record mixing among three components: mantle sulfur, oxidized seawater sulfur (e.g., SO4), and reduced elemental sulfur (e.g., S8). Petrographic evidence in conjunction with Δ33S and Δ36S data suggest that MIF-S was acquired during the deposition of shales and basalts present in the Kalgoorlie Terrane and later mixed with mantle-derived sulfur during the mineralization events. The negative δ34S values that predominate in Fimiston style mineralization are consistent with a prevalence of oxidized fluids during the ore-forming process, as reflected by the presence of hematite-pyrite-magnetite-gold assemblages. Conversely, the positive δ34S values that dominate in the Mt Charlotte and Oroya mineralization styles reflect a reducing environment, as reflected by the presence of pyrite-pyrrhotite-gold assemblages.

KW - Archean

KW - Gold

KW - Mass independent fractionation

KW - Orogenic

KW - Sulfur isotopes

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U2 - 10.1007/s00126-018-0828-y

DO - 10.1007/s00126-018-0828-y

M3 - Article

JO - Mineralium Deposita: international journal of geology, mineralogy, and geochemistry of mineral deposits

JF - Mineralium Deposita: international journal of geology, mineralogy, and geochemistry of mineral deposits

SN - 0026-4598

ER -