Results 141 to 150 of about 330,203 (416)
Slabs in the lower mantle and their modulation of plume formation [PDF]
, 2002 Numerical mantle convection models indicate that subducting slabs can reach the core-mantle boundary (CMB) for a wide range of assumed material properties and plate tectonic histories.
Gurnis, Michael, Han, Lijie, Tan, Eh
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'Genesis': A takeover from field-responsive matter? [PDF]
arXiv, 2010 Cairns-Smith (2008) has argued for a pre-Darwinian era, with a simpler basis for life's functioning via primitive "crystal genes" (information transfer, kinetic control on metabolic reactions). At the other extreme, guided by the structural similarity of clusters in early-evolved enzymes to iron-sulphide minerals like greigite, the hydrothermal mound ...
arxiv
Geochemistry of uranium in apatite and phosphorite [PDF]
, 1958 Z.S. Altschulter +2 more
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Publications of the exobiology program for 1982. A special bibliography [PDF]
Chemical evolution, organic geochemistry, origin and evalution of life, planetary environments, life in the universe, search for extraterrestrial intelligence, and planetary protection are ...
Devincenzi, D. L., Pleasant, L. G.
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Nitrogen Oxide Concentrations in Natural Waters on Early Earth
, 2019 A key challenge in origins-of-life studies is estimating the abundances of species relevant to the chemical pathways proposed to have contributed to the emergence of life on early Earth.
Babbin, Andrew R. +4 more
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The Depositional Record, EarlyView.A limestone cave in the NW Dinarides exhibits an anomalous presence of montmorillonite clay, not commonly found in surrounding caves, posing questions about its origin and age. Analysis reveals a composition similar to weathered tephra from the Smrekovec Volcanic Complex, suggesting transport by north‐east winds.
Nadja Zupan Hajna +12 more
wiley +1 more source
A ~60 Myr periodicity is common to marine-87Sr/86Sr, fossil biodiversity, and large-scale sedimentation: what does the periodicity reflect? [PDF]
Journal of Geology, 120, 217-226 (2012), 2012 We find that the marine 87Sr/86Sr record shows a significant periodicity of 59.3 \pm 3 Myr. The 87Sr/86Sr record is 171{\deg} \pm 12{\deg}out of phase with a 62 (\pm 3) Myr periodicity previously reported in the record of marine-animal diversity. These periodicities are close to 58 (\pm 4) Myr cycles found for the number of gap-bounded sedimentary ...
arxiv
Mineralogy and geochemistry of a uraniferous coal from the Red Desert Area, Sweetwater County, Wyoming [PDF]
, 1953 Irving A. Breger +3 more
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Geology and geochemistry of sulfide and sulfate deposition [PDF]
Factors contributing to the geology and geochemistry of sulfide and sulfate deposition are discussed.
Holser, W. T.
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