THE EARLY HISTORY OF ATMOSPHERIC OXYGEN: Homage to Robert M. Garrels
2005; Annual Reviews; Volume: 33; Issue: 1 Linguagem: Inglês
10.1146/annurev.earth.33.092203.122711
ISSN1545-4495
Autores Tópico(s)Geochemistry and Elemental Analysis
Resumo▪ Abstract This paper reviews the Precambrian history of atmospheric oxygen, beginning with a brief discussion of the possible nature and magnitude of life before the evolution of oxygenic photosynthesis. This is followed by a summary of the various lines of evidence constraining oxygen levels through time, resulting in a suggested history of atmospheric oxygen concentrations. Also reviewed are the various processes regulating oxygen concentrations, and several models of Precambrian oxygen evolution are presented. A sparse geologic record, combined with uncertainties as to its interpretation, yields only a fragmentary and imprecise reading of atmospheric oxygen evolution. Nevertheless, oxygen levels have increased through time, but not monotonically, with major and fascinating swings to both lower and higher levels.
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