Extraterrestrial organic matter preserved ...
Document type :
Article dans une revue scientifique: Article original
Permalink :
Title :
Extraterrestrial organic matter preserved in 3.33 Ga sediments from Barberton, South Africa
Author(s) :
Gourier, Didier [Auteur]
Binet, Laurent [Auteur]
Calligaro, Thomas [Auteur]
Cappelli, Serena [Auteur]
Vezin, Hervé [Auteur]
Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement - UMR 8516 [LASIRE]
Bréhéret, Jean [Auteur]
Hickman-Lewis, Keyron [Auteur]
Gautret, Pascale [Auteur]
Foucher, Frédéric [Auteur]
Campbell, Kathy [Auteur]
Westall, Frances [Auteur]
Binet, Laurent [Auteur]
Calligaro, Thomas [Auteur]
Cappelli, Serena [Auteur]
Vezin, Hervé [Auteur]
Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement - UMR 8516 [LASIRE]
Bréhéret, Jean [Auteur]
Hickman-Lewis, Keyron [Auteur]
Gautret, Pascale [Auteur]
Foucher, Frédéric [Auteur]
Campbell, Kathy [Auteur]
Westall, Frances [Auteur]
Journal title :
Geochimica et Cosmochimica Acta
Abbreviated title :
Geochimica et Cosmochimica Acta
Volume number :
285
Pages :
207-225
Publisher :
Elsevier BV
Publication date :
2019-08
ISSN :
0016-7037
English keyword(s) :
Extraterrestrial organic matter
Spinels
Electron paramagnetic resonance
Early Archean
Josefsdal chert formation
Spinels
Electron paramagnetic resonance
Early Archean
Josefsdal chert formation
HAL domain(s) :
Chimie/Chimie théorique et/ou physique
English abstract : [en]
Electron paramagnetic resonance (EPR) analysis of carbonaceous, volcanic, tidal sediments from the 3.33 Ga-old Josefsdal Chert (Kromberg Formation, Barberton Greenstone Belt), documents the presence of two types of insoluble ...
Show more >Electron paramagnetic resonance (EPR) analysis of carbonaceous, volcanic, tidal sediments from the 3.33 Ga-old Josefsdal Chert (Kromberg Formation, Barberton Greenstone Belt), documents the presence of two types of insoluble organic matter (IOM): (1) IOM similar to that previously found in Archean cherts from numerous other sedimentary rocks in the world and of purported biogenic origin; (2) anomalous IOM localized in a 2 mm-thick sedimentary horizon. Detailed analysis by continuous-wave-EPR and pulse-EPR reveals that IOM in this layer is similar to the insoluble component of the hydrogenated organic matter in carbonaceous chondrites, suggesting that this narrow sedimentary horizon has preserved organic matter of extraterrestrial origin. This conclusion is supported by the presence in this thin layer of another anomalous EPR signal at g = 3 attributed to Ni-Cr-Al ferrite spinel nanoparticles, which are known to form during atmospheric entry of cosmic objects. From this EPR analysis, it was deduced that the anomalous sedimentary layer originates from deposition, in a nearshore environment, of a cloud of tiny dust particles originating from a flux of micrometeorites falling through the oxygen-poor Archean atmosphere.Show less >
Show more >Electron paramagnetic resonance (EPR) analysis of carbonaceous, volcanic, tidal sediments from the 3.33 Ga-old Josefsdal Chert (Kromberg Formation, Barberton Greenstone Belt), documents the presence of two types of insoluble organic matter (IOM): (1) IOM similar to that previously found in Archean cherts from numerous other sedimentary rocks in the world and of purported biogenic origin; (2) anomalous IOM localized in a 2 mm-thick sedimentary horizon. Detailed analysis by continuous-wave-EPR and pulse-EPR reveals that IOM in this layer is similar to the insoluble component of the hydrogenated organic matter in carbonaceous chondrites, suggesting that this narrow sedimentary horizon has preserved organic matter of extraterrestrial origin. This conclusion is supported by the presence in this thin layer of another anomalous EPR signal at g = 3 attributed to Ni-Cr-Al ferrite spinel nanoparticles, which are known to form during atmospheric entry of cosmic objects. From this EPR analysis, it was deduced that the anomalous sedimentary layer originates from deposition, in a nearshore environment, of a cloud of tiny dust particles originating from a flux of micrometeorites falling through the oxygen-poor Archean atmosphere.Show less >
Language :
Anglais
Audience :
Internationale
Popular science :
Non
Administrative institution(s) :
Université de Lille
CNRS
CNRS
Collections :
Research team(s) :
Propriétés magnéto structurales des matériaux (PMSM)
Submission date :
2021-06-17T12:20:54Z
2021-06-28T11:55:42Z
2021-06-28T11:55:42Z