Title :

Influence of phyllosilicates on the hydrothermal alteration of organic matter in asteroids: experimental perspectives

Author(s) :

Vinogradoff, V. [Auteur]
Le Guillou, Corentin [Auteur]
Unité Matériaux et Transformations - UMR 8207 [UMET]
Bernard, Sylvain [Auteur]
Viennet, J.C. [Auteur]
Jaber, M. [Auteur]
Remusat, Laurent [Auteur]

Journal title :

Geochimica et Cosmochimica Acta

Abbreviated title :

Geochimica et Cosmochimica Acta

Publisher :

Elsevier BV

Publication date :

2019-10

ISSN :

0016-7037

HAL domain(s) :

Physique [physics]/Matière Condensée [cond-mat]/Science des matériaux [cond-mat.mtrl-sci]
Chimie/Matériaux
Physique [physics]/Physique [physics]/Géophysique [physics.geo-ph]
Physique [physics]/Astrophysique [astro-ph]
Planète et Univers [physics]/Astrophysique [astro-ph]
Planète et Univers [physics]/Sciences de la Terre

English abstract : [en]

The origin of the diverse organic compounds present in carbonaceous chondrites (CC) remains uncertain. We aim at investigating the role that hydrothermal alteration may have had on the molecular evolution of organic matter ...
Show more >The origin of the diverse organic compounds present in carbonaceous chondrites (CC) remains uncertain. We aim at investigating the role that hydrothermal alteration may have had on the molecular evolution of organic matter (OM). In particular, within CC matrices, OM is intimately embedded within phyllosilicates down to the nanometer scale, which raises the question of the influence of phyllosilicates on OM transformation during hydrothermal alteration on parent bodies. We conducted hydrothermal experiments at 150°C and alkaline pH, using a well-known molecule present in processed interstellar ice analogues, the hexamethylenetetramine (HMT), in the presence of Al- and Fe-rich smectites. Experimental products were characterized by gas chromatography mass spectrometry, infrared spectroscopy, X-ray diffraction and synchrotron-based X-ray absorption near edge structure spectroscopy. Within 31 days, the HMT+smectites+H2O system leads to (1) the formation of a diverse suite of soluble organic compounds, yet less abundant and less complex than in the absence of smectite, (2) carbon-rich smectite residues (3.8 wt.% and 2.6 wt.% of carbon for the Al- and Fe-rich smectite residues, respectively). In addition, the abundance and molecular composition of the final organic compounds depend on the nature of the phyllosilicate (Al vs. Fe-smectite). Various and complex interaction mechanisms could occur between OM and smectite. Physisorption, chemisorption and intercalation processes have likely entrapped a significant portion of the organic compounds, thereby altering their chemical evolution. The present work demonstrates that the presence and the nature of phyllosilicates influences the reaction pathways of organic compounds during hydrothermal alteration and that the presence of organic compounds may impact the mineral assemblage. This could have had significant importance for the co-evolution of OM and mineral phases in primitive bodies during hydrothermal alteration.Show less >

Language :

Anglais

Peer reviewed article :

Oui

Audience :

Non spécifiée

Administrative institution(s) :

Université de Lille
CNRS
INRA
ENSCL

Collections :

• Unité Matériaux et Transformations (UMET) - UMR 8207

Research team(s) :

Matériaux Terrestres et Planétaires

Submission date :

2019-11-04T13:24:43Z
2019-11-12T12:23:23Z