Extraterrestrial organic matter preserved ...
Type de document :
Article dans une revue scientifique: Article original
URL permanente :
Titre :
Extraterrestrial organic matter preserved in 3.33 Ga sediments from Barberton, South Africa
Auteur(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]
Titre de la revue :
Geochimica et Cosmochimica Acta
Nom court de la revue :
Geochimica et Cosmochimica Acta
Numéro :
285
Pagination :
207-225
Éditeur :
Elsevier BV
Date de publication :
2019-08
ISSN :
0016-7037
Mot(s)-clé(s) en anglais :
Extraterrestrial organic matter
Spinels
Electron paramagnetic resonance
Early Archean
Josefsdal chert formation
Spinels
Electron paramagnetic resonance
Early Archean
Josefsdal chert formation
Discipline(s) HAL :
Chimie/Chimie théorique et/ou physique
Résumé en anglais : [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 ...
Lire la suite >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.Lire moins >
Lire la suite >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.Lire moins >
Langue :
Anglais
Audience :
Internationale
Vulgarisation :
Non
Établissement(s) :
Université de Lille
CNRS
CNRS
Collections :
Équipe(s) de recherche :
Propriétés magnéto structurales des matériaux (PMSM)
Date de dépôt :
2021-06-17T12:20:54Z
2021-06-28T11:55:42Z
2021-06-28T11:55:42Z