Conditions of subaerial weathering of basalts in the Neoarchean and Paleoproterozoic

Alfimova, N. A.; Matrenichev, V. A.; Filho, Carlos Roberto de Souza

doi:10.1016/j.precamres.2013.09.013

Cited by 12 publications

(5 citation statements)

References 78 publications

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“…4c ), and the cradle fluid was enriched in reduced carbon. The weakly acidic pH suggested by this analysis also implies that the atmosphere was not necessarily CH 4 -dominated 46 , but may instead have contained a hydrocarbon haze 47 that provided C and N-bearing compounds. Alternatively, the cradle environment could have been at a cooling periphery of a dry-land hydrothermal system 11 .…”

Section: Resultsmentioning

confidence: 79%

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Geochemical constraints on the Hadean environment from mineral fingerprints of prokaryotes

Silva

Schneider

Abrevaya

et al. 2017

Sci Rep

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The environmental conditions on the Earth before 4 billion years ago are highly uncertain, largely because of the lack of a substantial rock record from this period. During this time interval, known as the Hadean, the young planet transformed from an uninhabited world to the one capable of supporting, and inhabited by the first living cells. These cells formed in a fluid environment they could not at first control, with homeostatic mechanisms developing only later. It is therefore possible that present-day organisms retain some record of the primordial fluid in which the first cells formed. Here we present new data on the elemental compositions and mineral fingerprints of both Bacteria and Archaea, using these data to constrain the environment in which life formed. The cradle solution that produced this elemental signature was saturated in barite, sphene, chalcedony, apatite, and clay minerals. The presence of these minerals, as well as other chemical features, suggests that the cradle environment of life may have been a weathering fluid interacting with dry-land silicate rocks. The specific mineral assemblage provides evidence for a moderate Hadean climate with dry and wet seasons and a lower atmospheric abundance of CO2 than is present today.

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Section: Resultsmentioning

confidence: 79%

“…However, all other elements necessary for life besides C and N could be mobilized from host rocks. (The works described in references 44 , 46 , 47 approach Archean environments only. There is very little information about the Hadean.…”

Section: Resultsmentioning

confidence: 99%

Geochemical constraints on the Hadean environment from mineral fingerprints of prokaryotes

Silva

Schneider

Abrevaya

et al. 2017

Sci Rep

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“…The wavelength of UV light () was between 200 and 400 nm, representing the range compensating the shielding effect for <200 nm by the CO 2 -rich atmosphere. We assumed that the regolith was wet, and a dissolved ferrous iron concentration [Fe 2+ ] = 0.1 mM was used in accordance with previous Archean weathering studies (29)(30)(31). This Fe 2+ concentration is comparable to dissolved ferrous iron values measured in modern anoxic groundwater (57,58).…”

Section: Archean Photogeochemical Modelmentioning

confidence: 99%

Anoxic photochemical weathering of pyrite on Archean continents

et al. 2022

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Sulfur is an essential element of life that is assimilated by Earth’s biosphere through the chemical breakdown of pyrite. On the early Earth, pyrite weathering by atmospheric oxygen was severely limited, and low marine sulfate concentrations persisted for much of the Archean eon. Here, we show an anoxic photochemical mechanism of pyrite weathering that could have provided substantial amounts of sulfate to the oceans as continents formed in the late Archean. Pyrite grains suspended in anoxic ferrous iron solutions produced millimolar sulfate concentrations when irradiated with ultraviolet light. The Fe 2+ (aq) was photooxidized, which, in turn, led to the chemical oxidation of pyritic sulfur. Additional experiments conducted with 2.68 Ga shale demonstrated that photochemically derived ferric iron oxidizes and dissolves sedimentary pyrite during chemical weathering. The results suggest that before the rise of atmospheric oxygen, oxidative pyrite weathering on Archean continents was controlled by the exposure of land to sunlight.

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“…In addition, since 2004, he participated as a co-investigator in the project dedicated to the reconstruction of the primordial Earth environment in the context of the origin of life. Since 2011, he worked at the Institute of Geosciences of UNICAMP and in the years 2011-2014 concluded a project supported by FAPESP "The quantification of the environmental constraints of Terra Hadeana: the cradle for emergent life on the young planet" (Alfimova et al, 2014). He is a programmer of the code CRONO (http://www.ige.unicamp.br/crono/) for geochemical modeling (Novoselov & Souza Filho, 2013, etc.)".…”

Section: Robert (Robertomentioning

confidence: 99%

Geologists of Russian origin in Latin America

Tchoumatchenco

Riccardi

Delga³

et al. 2018

RMLP

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Se describe la vida y trayectoria de geólogos que más allá de su nacionalidad (rusa, ucraniana, tártara, alemana, etc.), nacieron en territorios que pertenecieron al Imperio Ruso, la Unión Soviética o la Federación Rusa, y de sus descendientes graduados en geología, todos los cuales vivieron y trabajaron en países de Latinoamérica (en los cuales las lenguas que prevalecen son el español y el portugués). También se incluyen geólogos de la URSS que trabajaron temporariamente en algunos países de Latinoamérica y que con sus publicaciones contribuyeron a la Geología.

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Conditions of subaerial weathering of basalts in the Neoarchean and Paleoproterozoic

Cited by 12 publications

References 78 publications

Geochemical constraints on the Hadean environment from mineral fingerprints of prokaryotes

Geochemical constraints on the Hadean environment from mineral fingerprints of prokaryotes

Anoxic photochemical weathering of pyrite on Archean continents

Geologists of Russian origin in Latin America

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