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Updated: May 15, 2026
09:31
Preparation of Authigenic Pyrite from Methane-bearing Sediments for In Situ Sulfur Isotope Analysis Using SIMS
Published on: August 31, 2017
Microscale characterization of sulfur speciation in lake sediments
Teng Zeng1, William A Arnold, Brandy M Toner
1Department of Civil Engineering, University of Minnesota, 500 Pillsbury Drive Southeast, Minneapolis, Minnesota 55455, United States.
Environmental Science & Technology
|January 4, 2013
Summary
Prairie pothole lakes (PPLs) exhibit dynamic sulfur (S) speciation, with reduced organic S decreasing in spring/summer and increasing in summer/fall. These seasonal shifts in sedimentary sulfur pools influence element cycling in North American wetlands.
Area of Science:
- Environmental Science
- Geochemistry
- Wetland Ecology
Background:
- Prairie pothole lakes (PPLs) are sulfur-enriched wetlands in North America.
- Dynamic hydrogeochemistry and high sulfate levels create unique conditions for studying sedimentary sulfur (S).
Purpose of the Study:
- To define and quantify solid-phase S pools in PPL sediments.
- To track seasonal dynamics of S speciation within these unique wetland environments.
Main Methods:
- Developed a quantitative X-ray microprobe method using S 1s X-ray absorption near-edge structure (XANES) spectroscopy.
- Employed multienergy X-ray fluorescence mapping to analyze S speciation.
Main Results:
- Identified three main S pools: pyritic S, reduced organic S, and oxidized S.
- Observed significant seasonal variation in S speciation, with reduced organic S decreasing in spring/summer and increasing in summer/fall.
- Pyritic S remained relatively constant (approximately 22 mol %) throughout the year.
Conclusions:
- Sedimentary S speciation in PPLs exhibits a distinct seasonal cycle.
- These seasonal changes in sulfur pools have significant implications for the cycling of other elements, such as mercury, in prairie wetlands.
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