Journal articles
Age of metamorphism and deformation in the Montagne Noire dome (French Massif Central): Tapping into the memory of fine-grained gneisses using monazite U-Th-Pb geochronology
Abstract : Recent work has revealed that the Montagne Noire dome, located in the foreland of the Variscan belt (French Massif Central), contains a record of nearly coeval, late Variscan eclogitization and migmatization. Given these new results, it is important to understand the chronology of events that produced high-grade metamorphism and exhumation. Using U-Th-Pb dating of monazite, this study confirms ages of ~315–300 Ma for high-T metamorphism in the augen gneiss that makes up a large fraction of the Montagne Noire dome, and documents for the first time ~295 Ma monazite ages in compositionally varied fine-grained gneisses that form folded continuous layers within the core of the dome. The fine-grained gneiss layers are intensely sheared and are interpreted to have localized late, high-T deformation in the core of the dome. These sheared fine-grained gneisses form a network of shear zones that were kinematically linked to the extensional and strike-slip deformation zones that exhumed the Montagne Noire dome in a pull-apart (s.l.) domain. Continued deformation-recrystallization and fluid flow within these shear zones likely drove rejuvenation of monazite for ~5 million years after much of the melt had crystallized in the Montagne Noire dome.
Cited literature [105 references]
https://hal.archives-ouvertes.fr/hal-02948541
Contributor : Françoise Roger <>
Submitted on : Thursday, October 29, 2020 - 5:31:12 PM
Last modification on : Tuesday, April 20, 2021 - 12:12:17 PM
Long-term archiving on: : Saturday, January 30, 2021 - 6:34:11 PM
Contributor : Françoise Roger <>
Submitted on : Thursday, October 29, 2020 - 5:31:12 PM
Last modification on : Tuesday, April 20, 2021 - 12:12:17 PM
Long-term archiving on: : Saturday, January 30, 2021 - 6:34:11 PM
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