Title :

Detection of incipient aqueous alteration in carbonaceous chondrites

Author(s) :

Krämer Ruggiu, L. [Auteur]
Centre Européen de Recherche et d'Enseignement des Géosciences de l'Environnement [CEREGE]
Devouard, B. [Auteur]
Centre Européen de Recherche et d'Enseignement des Géosciences de l'Environnement [CEREGE]
Gattacceca, J. [Auteur]
Centre Européen de Recherche et d'Enseignement des Géosciences de l'Environnement [CEREGE]
Bonal, L. [Auteur]
Institut de Planétologie et d'Astrophysique de Grenoble [IPAG]
Leroux, Hugues [Auteur]
Unité Matériaux et Transformations - UMR 8207 [UMET]
Eschrig, J. [Auteur]
Institut de Planétologie et d'Astrophysique de Grenoble [IPAG]
Borschneck, D. [Auteur]
Centre Européen de Recherche et d'Enseignement des Géosciences de l'Environnement [CEREGE]
King, A.J. [Auteur]
The Natural History Museum [London] [NHM]
Beck, P. [Auteur]
Institut de Planétologie et d'Astrophysique de Grenoble [IPAG]
Marrocchi, Y. [Auteur]
Centre de Recherches Pétrographiques et Géochimiques [CRPG]
Debaille, V. [Auteur]
Laboratoire Géochimie, Traçage Isotopique, Minéral et élémentaire - G-Time (Bruxelles, Belgium)
Hanna, R.D. [Auteur]
University of Texas at Austin [Austin]
Grauby, O. [Auteur]
Centre Interdisciplinaire de Nanoscience de Marseille [CINaM]

Journal title :

Geochimica et Cosmochimica Acta

Abbreviated title :

Geochimica et Cosmochimica Acta

Volume number :

336

Pages :

308-331

Publisher :

Elsevier BV

Publication date :

2022-11

ISSN :

0016-7037

English keyword(s) :

Carbonaceous chondrites
Ungrouped chondrites
Aqueous alteration

HAL domain(s) :

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

English abstract : [en]

We discuss if the detection of aqueous alteration depends on the techniques that are used. We apply different methods to estimate the extent of aqueous alteration on four ungrouped carbonaceous chondrites showing limited ...
Show more >We discuss if the detection of aqueous alteration depends on the techniques that are used. We apply different methods to estimate the extent of aqueous alteration on four ungrouped carbonaceous chondrites showing limited aqueous alteration and thermal metamorphism: Chwichiya 002, El Médano (EM) 200, Northwest Africa (NWA) 12957 and NWA 11750, classified as C3 or C3.00-ung. The aim is to propose a reliable methodology to identify the most primitive chondrites. Chwichiya 002, NWA 11750 and NWA 12957 display very primitive matrices and could be amongst the most primitive chondrites currently known, similar to the least altered lithologies of the CM chondrites Paris (CM2.9) and Asuka (A) 12085 (CM2.8), A 12236 (CM2.9) and A 12169 (CM3.0). The structure of organic matter and Cr2O3 in ferroan olivines show that the four meteorites have been less heated than the least metamorphosed standard/reference type 3 chondrite, Semarkona (LL3.00), with Chwichiya 002, NWA 12957 and NWA 11750 similar to the CO3.0 s, Acfer 094 (C2-ung) and Paris meteorites. Chwichiya 002 and NWA 12957 show similar alteration phases and degree of alteration, with high abundances of amorphous material with embedded metal and sulfide, resembling Glass with Embedded Metal and Sulfide (GEMS)-like materials, and tochilinite-cronstedtite intergrowths (TCIs) as the major alteration phases. The matrix in NWA 11750 contains aggregates of nanoscale olivine crystals and abundant carbonates, observed as micrometer-sized carbonate veins surrounding chondrules, and as nanoscale carbonates mixed with the fine-grained materials. It also contains abundant grains of metal and a low abundance of phyllosilicates. El Medano 200 shows a high abundance of magnetite (∼10 vol%), nanoscale phyllosilicates, troilite, and organic matter. The variability of the secondary alteration phases in the meteorites suggests different alteration mechanisms, likely depending on both the starting composition of the meteorites and the composition of the fluids of alteration.Show less >

Language :

Anglais

Audience :

Internationale

Popular science :

Non

Administrative institution(s) :

Université de Lille
CNRS
INRAE
ENSCL

Collections :

• Unité Matériaux et Transformations (UMET) - UMR 8207

Research team(s) :

Matériaux Terrestres et Planétaires

Submission date :

2023-06-21T15:43:58Z
2023-06-23T06:10:32Z