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dc.contributor.authorMansard, Nicolas
dc.contributor.authorStunitz, Holger
dc.contributor.authorRaimbourg, Hugues
dc.contributor.authorPrécigout, Jacques
dc.date.accessioned2020-05-08T12:49:07Z
dc.date.available2020-05-08T12:49:07Z
dc.date.embargoEndDate2022-02-09
dc.date.issued2020-02-09
dc.description.abstractIn order to study the mutual effect of deformation and mineral reactions, we have conducted shear experiments on fine-grained plagioclase-pyroxene assemblages in a Griggs-type solid-medium deformation apparatus. Experiments were performed at a constant shear strain rate of 10<sup>−5</sup> s<sup>−1</sup>, a confining pressure of 1 GPa and temperatures of 800, 850 and 900 °C. While the peak stress of plagioclase + orthopyroxene assemblages reaches values between those of the end-member phases, the strength of polymineralic materials strongly decreases after peak stress and reaches flow stresses that stabilize far below those of the weaker phase (plagioclase). This weakening correlates with the coeval development of high-strain shear zones where new phases are preferentially produced, including new pyroxene, plagioclase and amphibole. The reaction products mostly occur as intimately mixed phases within fine-grained and interconnected shear bands, together with different compositions with respect to the starting material. This indicates that deformation significantly enhances the kinetics of mineral reactions, which in turn strongly weaken the deforming sample, here attributed to a switch to grain-size-sensitive diffusion creep through phase nucleation and grain size reduction. Such an interplay between deformation and mineral reactions may have strong implications for the initiation, development, and durability of shear zones in the lower crust.en_US
dc.descriptionAccepted manuscript version, licensed <a href=http://creativecommons.org/licenses/by-nc-nd/4.0/> CC BY-NC-ND 4.0. </a>en_US
dc.identifier.citationMansard, Stunitz H, Raimbourg H, Précigout J. The role of deformation-reaction interactions to localize strain in polymineralic rocks: Insights from experimentally deformed plagioclase-pyroxene assemblages. Journal of Structural Geology. 2020;134:104008:1-18en_US
dc.identifier.cristinIDFRIDAID 1809224
dc.identifier.doi10.1016/j.jsg.2020.104008
dc.identifier.issn0191-8141
dc.identifier.issn1873-1201
dc.identifier.urihttps://hdl.handle.net/10037/18251
dc.language.isoengen_US
dc.publisherElsevieren_US
dc.relation.journalJournal of Structural Geology
dc.relation.projectIDEC/FP7: 290864en_US
dc.relation.projectIDAndre: Labex VOLTAIRE, ANR-10-LABX-100-01en_US
dc.relation.projectIDinfo:eu-repo/grantAgreement/EC/FP7-IDEAS-ERC/290864/EU/Rheology of the continental lithosphere, a geological, experimental and numerical approach/RHEOLITH/en_US
dc.rights.accessRightsembargoedAccessen_US
dc.rights.holder© 2020 Elsevier Ltd. All rights reserved.en_US
dc.subjectVDP::Mathematics and natural science: 400::Geosciences: 450en_US
dc.subjectVDP::Matematikk og Naturvitenskap: 400::Geofag: 450en_US
dc.titleThe role of deformation-reaction interactions to localize strain in polymineralic rocks: Insights from experimentally deformed plagioclase-pyroxene assemblagesen_US
dc.type.versionacceptedVersionen_US
dc.typeJournal articleen_US
dc.typeTidsskriftartikkelen_US
dc.typePeer revieweden_US


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