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Partitioning of Bacterial Communities between Seawater and Healthy, Black Band Diseased, and Dead Coral Surfaces
- J. Frias-Lopez, A. Zerkle, G. Bonheyo, B. Fouke
- Biology, Environmental ScienceApplied and Environmental Microbiology
- 1 May 2002
ABSTRACT Distinct partitioning has been observed in the composition and diversity of bacterial communities inhabiting the surface and overlying seawater of three coral species infected with black…
Geological constraints on the origin of oxygenic photosynthesis
The geological evidence for early oxygen and hypotheses for the controls on oxygen level are the basis for the interpretation of photosynthetic oxygen production as examined in this review.
A bistable organic-rich atmosphere on the Neoarchaean Earth
- A. Zerkle, M. Claire, S. Domagal‐Goldman, J. Farquhar, S. Poulton
- Geology, Environmental Science
- 1 May 2012
It has been hypothesized that, before widespread oxygenation about 2.45 billion years ago, the Earth’s atmosphere contained an organic haze similar to that on Titan. However, these theoretical…
Sulfate was a trace constituent of Archean seawater
Low levels of sulfate allowed for the preservation of mass-independent isotope signatures in the Archean, yet open questions frustrate the translation of modern measurements of sulfur isotope fractionations into estimates of Archean seawater sulfate concentrations.
High isotope fractionations during sulfate reduction in a low-sulfate euxinic ocean analog
A detailed record of the early-Earth sulfur (S) cycle is chronicled by the S isotope values of sulfide and sulfate preserved in the rock record. Interpretation of this record rests on our…
Biogeochemical signatures through time as inferred from whole microbial genomes
Geochemi- cal signatures and phylogenetic relationships of prokaryotes from whole genome sequences are deduced and this link is used to infer geochemical aspects of the biosphere through time.
Onset of the aerobic nitrogen cycle during the Great Oxidation Event
The interpretation of the nitrogen isotope data in the context of iron speciation and carbon isotopeData suggests biogeochemical cycling across a dynamic redox boundary, with primary productivity fuelled by chemoautotrophic production and a nitrogen cycle dominated by nitrogen loss processes using newly available marine oxidants.
Pathways for Neoarchean pyrite formation constrained by mass-independent sulfur isotopes
- J. Farquhar, J. Cliff, B. Harms
- Geology, Environmental ScienceProceedings of the National Academy of Sciences
- 13 February 2013
It is suggested that Neoarchean ocean basins had two coexisting, significantly sized sulfur pools and that the pathways forming pyrite precursors played an important role in establishing how the isotopic characteristics of each of these pools was transferred to the sedimentary rock record.
Multiple oscillations in Neoarchaean atmospheric chemistry
Two-billion-year-old evaporites capture Earth’s great oxidation
These results show that substantial amounts of surface oxidant accumulated during this critical transition in Earth’s oxygenation, and provide a constraint on the magnitude and timing of early Earth's response to the Great Oxidation Event 2.3 billion years ago.