Titre :

Mechanical twinning of monazite expels radiogenic lead

Auteur(s) :

Fougerouse, D. [Auteur]
Curtin University
Reddy, S.M. [Auteur]
Curtin University
Seydoux-Guillaume, A.-M. [Auteur]
Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement [LGL-TPE]
Kirkland, C.L. [Auteur]
Curtin University
Erickson, T.M. [Auteur]
NASA Johnson Space Center [JSC]
Curtin University
Saxey, D.W. [Auteur]
Curtin University
Rickard, W.D.A. [Auteur]
Curtin University
Jacob, Damien [Auteur]
Unité Matériaux et Transformations - UMR 8207 [UMET]
Leroux, Hugues [Auteur]
Unité Matériaux et Transformations - UMR 8207 [UMET]
Clark, C. [Auteur]
Curtin University

Titre de la revue :

Geology

Éditeur :

Geological Society of America

Date de publication :

2020-11-25

Discipline(s) HAL :

Planète et Univers [physics]/Sciences de la Terre/Géophysique [physics.geo-ph]

Résumé en anglais : [en]

Mechanical twins form by the simple shear of the crystal lattice during deformation. In order to test the potential of narrow twins in monazite to record the timing of their formation, we investigated a ca. 1700 Ma monazite ...
Lire la suite >Mechanical twins form by the simple shear of the crystal lattice during deformation. In order to test the potential of narrow twins in monazite to record the timing of their formation, we investigated a ca. 1700 Ma monazite grain (from the Sandmata Complex, Rajasthan, India) deformed at ca. 980 Ma, by electron backscattered diffraction (EBSD), transmission electron microscopy (TEM), and atom probe tomography (APT). APT 208Pb/232Th ages indicate that the twin was entirely reset by radiogenic Pb loss during its formation at conditions far below the monazite closure temperature. The results are consistent with a model where Pb is liberated during rupture of rare earth element–oxygen (REE-O) bonds in the large [REE]O9 polyhedra during twinning. Liberated Pb likely migrated along fast diffusion pathways such as crystal defects. The combination of a quantitative microstructural investigation and nano-geochronology provides a new approach for understanding the history of accessory phases.Lire moins >

Langue :

Anglais

Comité de lecture :

Oui

Audience :

Non spécifiée

Établissement(s) :

Université de Lille
CNRS
INRA
ENSCL

Collections :

• Unité Matériaux et Transformations (UMET) - UMR 8207

Équipe(s) de recherche :

Matériaux Terrestres et Planétaires

Date de dépôt :

2021-03-11T16:45:23Z
2021-03-12T10:54:51Z