Titre :

Pervasive shock melting at >65 GPa in a Martian basalt, the shergottite Northwest Africa 14672

Auteur(s) :

Hewins, R. H. [Auteur]
Institut de minéralogie, de physique des matériaux et de cosmochimie [IMPMC]
Leroux, Hugues [Auteur]
Unité Matériaux et Transformations - UMR 8207 [UMET]
Jacob, Damien [Auteur]
Unité Matériaux et Transformations - UMR 8207 [UMET]
Pont, S. [Auteur]
Institut de minéralogie, de physique des matériaux et de cosmochimie [IMPMC]
Beyssac, O. [Auteur]
Institut de minéralogie, de physique des matériaux et de cosmochimie [IMPMC]
Malarewicz, V. [Auteur]
Institut de minéralogie, de physique des matériaux et de cosmochimie [IMPMC]
Lorand, J.‐P. [Auteur]
Laboratoire de Planétologie et Géodynamique [UMR 6112] [LPG]
Zanetta, P.‐M. [Auteur]
University of Arizona
Zanda, B. [Auteur]
Institut de minéralogie et de physique des milieux condensés [IMPMC]

Titre de la revue :

Meteoritics & Planetary Science

Nom court de la revue :

Meteorit & Planetary Scien

Éditeur :

Wiley

Date de publication :

2023-07-06

ISSN :

1086-9379

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]

Shergottites have provided abundant information on the volcanic and impact history of Mars. Northwest Africa (NWA) 14672 contributes to both of these aspects. It is a vesicular ophitic depleted olivine–phyric shergottite, ...
Lire la suite >Shergottites have provided abundant information on the volcanic and impact history of Mars. Northwest Africa (NWA) 14672 contributes to both of these aspects. It is a vesicular ophitic depleted olivine–phyric shergottite, with average plagioclase An61Ab39Or0.2. It is highly ferroan, with pigeonite compositions En49-25Fs41-61Wo10-14 like those of basaltic shergottites, for example, NWA 12335. Olivine (Fo53-15) has discrete ferroan overgrowths, more ferroan when in contact with plagioclase than when enclosed by pyroxene. The pyroxene (a continuum of augite, subcalcic augite, and pigeonite) is patchy, with ragged “cores” enveloped or invaded by ferroan pyroxene. Magma mixing may be responsible for capture of olivine and formation of pyroxene mantles. The plagioclase is maskelynite-like in appearance, but the original laths were (congruently) melted and the melt partly crystallized as fine dendrites. Most of the 14% vesicles occur within plagioclase. Olivine, pyroxene, and ilmenite occur in part as fine aggregates crystallized after congruent melting with limited subsequent liquid mixing. There are two fine-grained melt components, barred plagioclase with interstitial Fe-bearing phases, and glass with olivine dendrites, derived by melting of mainly plagioclase and mainly pyroxene, respectively. Rare silica particles contain coesite and/or quartz, and silica glass. The rock has experienced >50% melting, compatible with peak pressure >~65 GPa. It is the most highly shocked shergottite so far, at shock stage S6/7. It may belong to the group of depleted shergottites ejected at ~1 Myr from Tooting Crater.Lire moins >

Langue :

Anglais

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 :

2023-10-27T12:22:22Z
2023-10-31T11:23:56Z