Stable sulfur isotope dynamics in an acid sulfate soil landscape following seawater inundation

C. A. Maher, L. A. Sullivan

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

In 2002 a tidally driven seawater exchange remediation strategy was successfully implemented on a severely acidified tropical coastal landscape dominated by acid sulfate soils (ASS) in northern Australia. This study examined changes in the stable sulfur isotope signatures in a range of sulfide and sulfate (SO4) fractions at three sites with different levels of exposure to the tidally driven seawater exchange remediation. δ34S in the acid soluble SO4 fraction (e.g. jarosite) was less depleted in 34S than the corresponding sulfide, indicating a degree of fractionation during sulfide oxidation and jarosite precipitation. The δ34S of jarositic-SO4 was similar at all three sites indicating the appreciable stability of jarositic-SO4 even after extended exposure to seawater. δ34S of the water soluble, exchangeable and schwertmannitic-SO4 reflect conditions post remediation and indicate the relative contributions from two potential SO4 sources – a lighter SO4 derived from the oxidation of pyrite, and a heavier SO4 derived from the seawater. The δ34S of the contemporary surficial sulfide accumulations also reflect a SO4 contribution from seawater used for remediation and were isotopically different from the relict sulfides found at depth at all sites. δ34S of water soluble sulfate allowed the progress of the remediation to be traced down the soil profile. This study demonstrates the utility of stable sulfur isotope signatures in various sulfide and SO4 fractions to trace the sulfur geochemical pathways occurring in soils, in this case as a result of the introduction of tidally driven sea water.

Original languageEnglish
Pages (from-to)205-212
Number of pages8
JournalChemical Geology
Volume439
DOIs
Publication statusPublished - 2016
Externally publishedYes

Fingerprint

Sulfur Isotopes
acid sulfate soil
sulfur isotope
Sulfides
Seawater
Sulfates
Remediation
stable isotope
sulfide
seawater
remediation
Soils
Acids
jarosite
Water
sulfate
oxidation
Oxidation
Fractionation
Sulfur

Cite this

@article{ac6e6cd21ef54c2bbd73ef8ffecc2c55,
title = "Stable sulfur isotope dynamics in an acid sulfate soil landscape following seawater inundation",
abstract = "In 2002 a tidally driven seawater exchange remediation strategy was successfully implemented on a severely acidified tropical coastal landscape dominated by acid sulfate soils (ASS) in northern Australia. This study examined changes in the stable sulfur isotope signatures in a range of sulfide and sulfate (SO4) fractions at three sites with different levels of exposure to the tidally driven seawater exchange remediation. δ34S in the acid soluble SO4 fraction (e.g. jarosite) was less depleted in 34S than the corresponding sulfide, indicating a degree of fractionation during sulfide oxidation and jarosite precipitation. The δ34S of jarositic-SO4 was similar at all three sites indicating the appreciable stability of jarositic-SO4 even after extended exposure to seawater. δ34S of the water soluble, exchangeable and schwertmannitic-SO4 reflect conditions post remediation and indicate the relative contributions from two potential SO4 sources – a lighter SO4 derived from the oxidation of pyrite, and a heavier SO4 derived from the seawater. The δ34S of the contemporary surficial sulfide accumulations also reflect a SO4 contribution from seawater used for remediation and were isotopically different from the relict sulfides found at depth at all sites. δ34S of water soluble sulfate allowed the progress of the remediation to be traced down the soil profile. This study demonstrates the utility of stable sulfur isotope signatures in various sulfide and SO4 fractions to trace the sulfur geochemical pathways occurring in soils, in this case as a result of the introduction of tidally driven sea water.",
keywords = "Isotope geochemistry, Jarosite, Pyrite oxidation, Tidal exchange",
author = "Maher, {C. A.} and Sullivan, {L. A.}",
year = "2016",
doi = "10.1016/j.chemgeo.2016.07.001",
language = "English",
volume = "439",
pages = "205--212",
journal = "Chemical Geology (Isotopic Geoscience) Section",
issn = "0009-2541",
publisher = "Elsevier",

}

Stable sulfur isotope dynamics in an acid sulfate soil landscape following seawater inundation. / Maher, C. A.; Sullivan, L. A.

In: Chemical Geology, Vol. 439, 2016, p. 205-212.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Stable sulfur isotope dynamics in an acid sulfate soil landscape following seawater inundation

AU - Maher, C. A.

AU - Sullivan, L. A.

PY - 2016

Y1 - 2016

N2 - In 2002 a tidally driven seawater exchange remediation strategy was successfully implemented on a severely acidified tropical coastal landscape dominated by acid sulfate soils (ASS) in northern Australia. This study examined changes in the stable sulfur isotope signatures in a range of sulfide and sulfate (SO4) fractions at three sites with different levels of exposure to the tidally driven seawater exchange remediation. δ34S in the acid soluble SO4 fraction (e.g. jarosite) was less depleted in 34S than the corresponding sulfide, indicating a degree of fractionation during sulfide oxidation and jarosite precipitation. The δ34S of jarositic-SO4 was similar at all three sites indicating the appreciable stability of jarositic-SO4 even after extended exposure to seawater. δ34S of the water soluble, exchangeable and schwertmannitic-SO4 reflect conditions post remediation and indicate the relative contributions from two potential SO4 sources – a lighter SO4 derived from the oxidation of pyrite, and a heavier SO4 derived from the seawater. The δ34S of the contemporary surficial sulfide accumulations also reflect a SO4 contribution from seawater used for remediation and were isotopically different from the relict sulfides found at depth at all sites. δ34S of water soluble sulfate allowed the progress of the remediation to be traced down the soil profile. This study demonstrates the utility of stable sulfur isotope signatures in various sulfide and SO4 fractions to trace the sulfur geochemical pathways occurring in soils, in this case as a result of the introduction of tidally driven sea water.

AB - In 2002 a tidally driven seawater exchange remediation strategy was successfully implemented on a severely acidified tropical coastal landscape dominated by acid sulfate soils (ASS) in northern Australia. This study examined changes in the stable sulfur isotope signatures in a range of sulfide and sulfate (SO4) fractions at three sites with different levels of exposure to the tidally driven seawater exchange remediation. δ34S in the acid soluble SO4 fraction (e.g. jarosite) was less depleted in 34S than the corresponding sulfide, indicating a degree of fractionation during sulfide oxidation and jarosite precipitation. The δ34S of jarositic-SO4 was similar at all three sites indicating the appreciable stability of jarositic-SO4 even after extended exposure to seawater. δ34S of the water soluble, exchangeable and schwertmannitic-SO4 reflect conditions post remediation and indicate the relative contributions from two potential SO4 sources – a lighter SO4 derived from the oxidation of pyrite, and a heavier SO4 derived from the seawater. The δ34S of the contemporary surficial sulfide accumulations also reflect a SO4 contribution from seawater used for remediation and were isotopically different from the relict sulfides found at depth at all sites. δ34S of water soluble sulfate allowed the progress of the remediation to be traced down the soil profile. This study demonstrates the utility of stable sulfur isotope signatures in various sulfide and SO4 fractions to trace the sulfur geochemical pathways occurring in soils, in this case as a result of the introduction of tidally driven sea water.

KW - Isotope geochemistry

KW - Jarosite

KW - Pyrite oxidation

KW - Tidal exchange

UR - http://www.scopus.com/inward/record.url?scp=84979019745&partnerID=8YFLogxK

UR - http://www.mendeley.com/research/stable-sulfur-isotope-dynamics-acid-sulfate-soil-landscape-following-seawater-inundation

U2 - 10.1016/j.chemgeo.2016.07.001

DO - 10.1016/j.chemgeo.2016.07.001

M3 - Article

VL - 439

SP - 205

EP - 212

JO - Chemical Geology (Isotopic Geoscience) Section

JF - Chemical Geology (Isotopic Geoscience) Section

SN - 0009-2541

ER -