Archaean atmosphere
From ResearchID.org
The hypothetical composition of the atmosphere in the early earth is called the Archaean atmosphere. An anoxic atmosphere with without oxygen is critically important for the abiogenic formation of biomolecules, as their formation is not stable in oxic atmospheres with oxygen present. Evidence has been presented for both oxic and anoxic atmospheres.
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Oxic atmosphere
Iron formations
Law, Phillips and Myers of the CSIRO review evidence for aoxic vs oxic archaean atmospheres and provide evidence for an oxic archean atmosphere using iron Pisoliths in Australian geological formations.The Earth may have had an oxygen-rich atmosphere as long ago as three billion years and possibly even earlier . . . Pisoliths have been a vital tool in the discovery of $5 billion worth of new gold deposits in WA
- Primodial air may have been breathable
- Jonathan Law, G. Neil Phillips, Russell, E. Myers Relevance of the Archaean Atmosphere to the Genesis of Banded Iron Formations, AusIMM Bulletin Nov/Dec 2002, 28-35
- G.Neill Phillips, Jonathan D. M Law, & Russell E. Myers, Is the Redox State of the Archaean Atmosphere Constrained? Soc. of Economic Geologists Newsletter Oct. 2001, No. 47 pp9-17 SEG Newsletter
Sulfur isotopes
Ohmoto et al. provide evidence for oxic archaean atmospheres based on sulfur isotope ratios in archaean rocks similar to modern ratios.
- Ohmoto et al., “Sulphur isotope evidence for an oxic Archaean atmosphere,” Nature 442, 908-911(24 August 2006) | doi:10.1038/nature05044; Received 21 June 2005; Accepted 10 July 2006.
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Archaean biomarkers
Dutkiewicz et al. find early biomarkers revealing photosynthesis early in the archaean, probably before 2.2 Ga. [1], [2]
Anoxic atmosphere
The archaean or primordial earth is commonly hypothesized to have had an anoxic atmosphere because of the necessity of anoxic conditions for the formation of amino acids necessary for abiogenesis.
Schaefer et al.'s (2006) model of outgassing chondritic material predicts that Earth's early atmosphere contained CH4, H2, H2O, N2, and NH3.
- Laura Schaefer, Bruce Fegley, Jr Outgassing of Ordinary Chondritic Material and Some of its Implications for the Chemistry of Asteroids, Planets, and Satellites
astro-ph/0606671 (submitted to Icarus)
Aerosol Formation
Models by Margaret Tolbert (U. Colorado) Melissa Trainer and Alexander Pavlov (U. Arizona), indicate that atmospheres with methane, nitrogen & carbon dioxide form a photochemical organic haze. [3]
Miller Urey experiment
Miller & Urey demonstrated formation of organic molecules including amino acids, in an anoxic atmosphere of nitrogen and methane with electric discharges.
- Wikipedia: Miller-Urey Experiment
- Miller-Urey experiment & Miller interview
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- Kristof Plankensteiner, Hannes Reiner1 and Bernd M. Rode, Amino acids on the rampant primordial Earth: Electric discharges and the hot salty ocean, Moledular Diversity Volume 10, Number 1 / February, 2006
References & Bibliography
- ↑ INVITED: THE USE OF BIOMARKERS FROM OIL INCLUSIONS TO CONSTRAIN PALEOPROTEROZOIC ECOSYSTEMS AND ENVIRONMENTSGEORGE, Simon C.1, DUTKIEWICZ, Adriana2, VOLK, Herbert1, RIDLEY, John3, and BUICK, Roger, Earth System Processes 2 (8–11 August 2005) Paper 16-1
- ↑ "Biomarkers from Huronian oil-bearing fluid inclusions: An uncontaminated record of life before the Great Oxidation Event." Adriana Dutkiewicz, Herbert Volk, Simon C. George, John Ridley and Roger Buick Geology: 2006, Vol. 34, No. 6, pp. 437*440.
- ↑ [http://www.telegraph.co.uk/news/main.jhtml?xml=/news/2006/11/10/usaturn110.xml Smoggy skies 'created life on Earth']
Andrew Snelling, The First atmosphere—geological evidences and their implications, Creation 3(4):46–52, November 1980
