Titre :

Tardi-magmatic iddingsite in the Martian Nakhlite NWA 817

Auteur(s) :

Megevand, V. [Auteur]
Muséum National d'Histoire Naturelle [Concarneau]
Viennet, J.-C. [Auteur]
Muséum national d'Histoire naturelle [MNHN]
Le Guillou, Corentin [Auteur]
1002334|||Unité Matériaux et Transformations - UMR 8207 [UMET] (VALID)
Guyot, F. [Auteur]
Muséum national d'Histoire naturelle [MNHN]
Bernard, S. [Auteur]
Muséum national d'Histoire naturelle [MNHN]

Titre de la revue :

Geochimica et Cosmochimica Acta

Nom court de la revue :

Geochimica et Cosmochimica Acta

Numéro :

393

Pagination :

318-333

Éditeur :

Elsevier BV

Date de publication :

2025-03

ISSN :

0016-7037

Mot(s)-clé(s) en anglais :

ddingsite
Fe/Mg-smectites
Deuteric alteration
Nakhlite
NWA 817
Mars

Discipline(s) HAL :

Chimie/Matériaux
Physique [physics]/Matière Condensée [cond-mat]/Science des matériaux [cond-mat.mtrl-sci]
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

Résumé en anglais : [en]

The mineral assemblage referred to as “iddingsite” has been described in Martian meteorites. In Nakhlites, this assemblage is mainly composed of Fe/Mg-rich phyllosilicates (such as serpentine and smectites) associated ...
Lire la suite >The mineral assemblage referred to as “iddingsite” has been described in Martian meteorites. In Nakhlites, this assemblage is mainly composed of Fe/Mg-rich phyllosilicates (such as serpentine and smectites) associated in some cases with Fe-oxides (such as ferrihydrite, goethite or (titano)magnetite) and carbonates, and occurs either as patches and veinlets in the mesostasis or as veins infiltrating olivines and clinopyroxenes. So far, iddingsite has usually been interpreted as a product of low-temperature (<150 ◦C) alteration of pre-existing silicates by (sub) surface water. Here, we report results of the petrographic study of a section of NWA 817 revealing that the olivine-hosted iddingsite veins are symmetrically structured with an internal part exhibiting a mica-celadonite composition and an external part displaying a nontronite-saponite composition. These features are consistent with a progressive differentiation of a residual magmatic fluid having infiltrated decompression-induced cracks of olivines at the end of the cooling sequence. We propose that this residual liquid directly produced the ferric mica-celadonite phyllosilicates while triggering the deuteric alteration of the hosting olivine (i.e. oxidative alteration during magma cooling), thereby producing an alteration front made of Fe-nontronite-saponite at the contact with olivine. Altogether, without excluding the possibility that other Nakhlites (such as Lafayette) may have experienced secondary alteration by (sub)surface Martian water, the observations reported in the present study rather point to the tardi-magmatic production of iddingsite in NWA 817.Lire moins >

Langue :

Anglais

Comité de lecture :

Oui

Audience :

Internationale

Vulgarisation :

Non

Établissement(s) :

Université de Lille
CNRS
INRAE
ENSCL

Collections :

• Unité Matériaux et Transformations (UMET) - UMR 8207

Équipe(s) de recherche :

Matériaux Terrestres et Planétaires

Date de dépôt :

2025-03-25T09:54:39Z
2025-03-26T08:41:08Z