3. 4-billion-year-old biogenic pyrites from Barberton, South Africa: Sulfur isotope evidence

Journal Article · Fri Oct 22 00:00:00 EDT 1993 · Science (Washington, D.C.); (United States)

DOI:https://doi.org/10.1126/science.11539502· OSTI ID:5242101

Ohmoto, H; Kakegawa, T ^[1]; Lowe, D R ^[2]

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1. Pennyslvania State Univ., University Park, PA (United States)
2. Stanford Univ., CA (United States)

Laser ablation mass spectroscopy analysis of sulfur isotopic compositions of microscopic-sized grains of pyrite that formed about 3.4 billion years ago in the Barberton Greenstone Belt, South Africa, show that the pyrite formed by bacterial reduction of seawater sulfate. These data imply that by about 3.4 billion years ago sulfate-reducing bacteria had become active, the oceans were rich in sulfate, and the atmosphere contained appreciable amounts (> > 10[sup [minus]13] of the present atmospheric level) of free oxygen.

• OSTI ID: 5242101
• Journal Information: Science (Washington, D.C.); (United States), Vol. 262:5133; ISSN 0036-8075
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
BIOSPHERE
SULFUR CYCLE
GEOLOGIC HISTORY
SULFUR ISOTOPES
ISOTOPE RATIO
ISOTOPES
540310* - Environment
Aquatic- Basic Studies- (1990-)
540110