Sulfate was a trace constituent of Archean seawater
Abstract
In the low-oxygen Archean world (>2400 million years ago), seawater sulfate concentrations were much lower than today, yet open questions frustrate the translation of modern measurements of sulfur isotope fractionations into estimates of Archean seawater sulfate concentrations. In the water column of Lake Matano, Indonesia, a low-sulfate analog for the Archean ocean, we find large (>20 per mil) sulfur isotope fractionations between sulfate and sulfide, but the underlying sediment sulfides preserve a muted range of δ^(34)S values. Using models informed by sulfur cycling in Lake Matano, we infer Archean seawater sulfate concentrations of less than 2.5 micromolar. At these low concentrations, marine sulfate residence times were likely 10^3 to 10^4 years, and sulfate scarcity would have shaped early global biogeochemical cycles, possibly restricting biological productivity in Archean oceans.
Additional Information
© 2014 American Association for the Advancement of Science. Received for publication 21 July 2014. Accepted for publication 3 October 2014. We thank A. Sturm and C. Henny for help with fieldwork. S. Poulton provided sediment δ^(34)S data. A. Hefford helped compile Archean S-isotope data. Funding to S.A.C. was provided by an Agouron Institute Geobiology Fellowship and a Natural Sciences and Engineering Research Council of Canada Postdoctoral Fellowship. Additional funding was provided by the Danish National Research Foundation (grant no. DNRF53) and the European Research Council. All data are available in the supplementary materials.Attached Files
Supplemental Material - 1258966_Data_S1.xlsx
Supplemental Material - Crowe.SM.pdf
Files
| Name | Size | Download all |
|---|---|---|
|
md5:33bc552bda9a76bd14bf3b45b65c2f1c
|
53.0 kB | Download |
|
md5:ef134de19e5947ec0cf93540dfe829dc
|
576.3 kB | Preview Download |
Additional details
- Eprint ID
- 50324
- DOI
- 10.1126/science.1258966
- Resolver ID
- CaltechAUTHORS:20141009-162752745
- Agouron Institute
- Natural Sciences and Engineering Research Council of Canada (NSERC)
- DNRF53
- Danish National Research Foundation
- European Research Council (ERC)
- Created
-
2014-11-06Created from EPrint's datestamp field
- Updated
-
2021-11-10Created from EPrint's last_modified field
- Caltech groups
- Division of Geological and Planetary Sciences