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| Titel |
Dynamics of slab detachment |
| VerfasserIn |
T. Duretz, S. M. Schmalholz, T. V. Gerya |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250060455
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| Zusammenfassung |
| Our study investigates the dynamics of slab detachment and evaluates the amount of time
necessary for slabs to detach. We combine both the results of two-dimensional numerical
modeling with the prediction of a one-dimensional analytical solution for viscous necking
under gravity. This tidy suggest that the dominant deformation mechanisms leading to slab
detachment is viscous necking, independently of the depth of slab detachment. Localised
simple shear may also occur when the slab dip is moderate, especially in the colder parts of
the slab. Brittle fracturing, or breaking, plays a minor role during the slab detachment
process. 2D thermo-mechanical simulations indicate that the duration of slab detachment is
short (< 4 Ma) and can occur in less than 0.5 Ma. No simple correlation between the
slab detachment depth and duration was found. Our results suggest that deep slab
detachments (> 250 km) can also occur within a short time (< 1 Ma). On the other
hand, slab detachments taking place between 35 and 250 km depth may last less
than 2 Ma. This aspect has implications for geodynamic interpretations using slab
detachment as explanation for processes such as melting, exhumation or surface uplift. |
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