Sulfate was a trace constituent of Archean seawater.
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.
Department of Microbiology and Immunology and Department of Earth, Ocean, and Atmospheric Sciences, University of British Columbia, Vancouver, British Columbia, Canada. NordCEE and Department of Biology, University of Southern Denmark, Odense, Denmark. sacrowe1@gmail.com.
Sean A
SA
Crowe
Department of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA.
Guillaume
G
Paris
Large Lakes Observatory and Department of Physics, University of Minnesota, Minneapolis, MN 55812, USA.
Sergei
S
Katsev
Department of Microbiology and Immunology and Department of Earth, Ocean, and Atmospheric Sciences, University of British Columbia, Vancouver, British Columbia, Canada. NordCEE and Department of Biology, University of Southern Denmark, Odense, Denmark.
CarriAyne
C
Jones
School of Geography and Earth Sciences, McMaster University, Hamilton, Ontario, Canada.
Sang-Tae
ST
Kim
Department of Earth and Environmental Sciences, University of St. Andrews, St. Andrews, UK.
Aubrey L
AL
Zerkle
Research Center for Limnology, Indonesian Institute of Sciences, Cibinong, West Java, Indonesia.
Sulung
S
Nomosatryo
Department of Geology, University of Kansas, Lawrence, KS 66045, USA.
David A
DA
Fowle
Department of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA.
Jess F
JF
Adkins
Department of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA.
Alex L
AL
Sessions
Department of Geology, University of Maryland, College Park, MD 20742, USA.
James
J
Farquhar
NordCEE and Department of Biology, University of Southern Denmark, Odense, Denmark.
Donald E
DE
Canfield
D001688:Biological Products / Q000138:chemical synthesis / Q000737:chemistry / Q000266:history*; D049690:History, Ancient; D007214:Indonesia; D012623:Seawater / Q000737:chemistry*; D013431:Sulfates / Q000032:analysis / Q000266:history*; D013460:Sulfur Isotopes / Q000032:analysis / Q000266:history
D001688:Biological Products; D013431:Sulfates; D013460:Sulfur Isotopes