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The character of the Moho and lower crust within Archean cratons and the tectonic implications [PDF]
Tectonophysics, 2013 Undisturbed mid Archean crust (stabilized by 3.0–2.9 Ga) has several characteristics that distinguish it from post Archean crust. Undisturbed mid-Archean crust has a low proportion of internal seismic boundaries (as evidenced by converted phases in ...
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Photosynthesis in the Archean Era
Photosynthesis Research, 2006The earliest reductant for photosynthesis may have been H2. The carbon isotope composition measured in graphite from the 3.8-Ga Isua Supercrustal Belt in Greenland is attributed to H2-driven photosynthesis, rather than to oxygenic photosynthesis as there would have been no evolutionary pressure for oxygenic photosynthesis in the presence of H2 ...
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Was There Really an Archean Phosphate Crisis?
Science, 2007During the Archean, massive amounts of iron were deposited in the form of banded iron formations. It has been suggested that sedimenting particles of ferric oxyhydroxide may have stripped dissolved phosphate from the oceans, causing a reduction in phytoplankton productivity.
Kurt O, Konhauser +3 more
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Rheological heterogeneity of Archean continental lithosphere: implications for Archean tectonics
7th SAGA Biennial Technical Meeting and Exhibition, 2001In this contribution we discuss the rheology of the Archean continental lithosphere. Decoupling of the upper crust and mantle lithosphere may be a common situation in any tectonically active region and was probably the rule rather than the exception during the Archean. This has major implications for the style of Archean tectonism.
H.A. Jelsma, P.H.G.M. Dirks, M.J. de Wit
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Revisiting an Archean Impact Layer
Science, 2002G. R. Byerly et al. 's report, “An archean impact layer from the Pilbara and Kaapvaal cratons” (23 Aug., p. [1325][1]), is an important addition to the growing literature on early Precambrian impact ejecta. Their zircon data provide compelling evidence that spherule layers in Australia and South Africa were formed simultaneously by a single impact ...
Bruce M, Simonson, Scott W, Hassler
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Chemical discontinuities in Archean metavolcanic terrains and the development of Archean crust
Precambrian Research, 1980Abstract Most large Archean greenstone belts ( ⋍ 2.7 Ga ), comprise thick (12–15 km) mafic to felsic metavolcanics sequences which exhibit consistent but discontinuous geochemical patterns resulting from mantle-crust processes. In a typical Archean metavolcanic sequence, thick (5–8 km) uniform tholeiitic basalt is followed by geochemically ...
A.M. Goodwin, I.E.M. Smith
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Archean ferropicrites and Early Archean deep mantle heterogeneity
Acta Petrologica Sinica, 2021WANG Chao, SONG ShuGuang
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Geochemistry of Precambrian carbonates: II. Archean greenstone belts and Archean sea water
Geochimica et Cosmochimica Acta, 1989Carbonate rocks with geological attributes of marine sediments are a minor component of the Archean greenstone belts. Despite their relative scarcity, these rocks are important because they record chemical and isotopic properties of coeval oceans.
J, Veizer +3 more
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Was There a Late Archean Biospheric Explosion?
Astrobiology, 2008There is a growing body of evidence which suggests that the evolution of the planet drives the evolution of the biosphere. There have been 2 significant stages in Earth history when atmospheric oxygen levels rose rapidly, and both appear to be associated with supercontinent cycles.
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The Problematic Rise of Archean Oxygen
Science, 2002In their intricate study, Catling et al . ([1][1]) attempted to explain the rise of atmospheric oxygen on the early Earth. The model they presented relies on a unique anaerobic ecosystem in which necessarily complex microbial fermentations interact closely with methanogens to decompose ...
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