Sulfate was a trace constituent of Archean seawater.
Science
; 346(6210): 735-9, 2014 Nov 07.
Article
in En
| MEDLINE
| ID: mdl-25378621
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.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Seawater
/
Sulfates
/
Biological Products
Type of study:
Prognostic_studies
Country/Region as subject:
Asia
Language:
En
Journal:
Science
Year:
2014
Document type:
Article
Affiliation country:
Denmark