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| Titel |
Role of strain weakening on continental plate tectonics |
| VerfasserIn |
Frédéric Gueydan, Jacques Précigout, Laurent Montesi |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250093451
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| Publikation (Nr.) |
 EGU/EGU2014-8172.pdf |
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| Zusammenfassung |
| Much debate exists concerning the strength distribution of the continental lithosphere, how it
controls lithosphere-scale strain localization and hence enables plate tectonics. No
rheological model proposed to date is comprehensive enough to describe both the
weakness of plate boundary and rigid-like behaviour of plate interiors. Here we show
that the duality of strength of the lithosphere corresponds to different stages of
microstructural evolution. Geological constraints on lithospheric strength and large
strain numerical experiments reveal that the development of layers containing weak
minerals and the onset of grain boundary sliding upon grain size reduction in olivine
cause strain localisation and reduce strength in the crust and subcontinental mantle,
respectively. The positive feedback between weakening and strain localization leads to the
progressive development of weak plate boundaries while plate interiors remain strong. |
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