 |
| Titel |
Thermomechanical modelling of slab eduction |
| VerfasserIn |
T. Duretz, T. V. Gerya, B. J. P. Kaus, T. B. Andersen |
| Konferenz |
EGU General Assembly 2012
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250060443
|
|
|
|
|
|
| Zusammenfassung |
| Our study presents the plate eduction model. This geodynamic process is characterized by the
extensional reactivation of a subduction zone which might take place after slab
detachment. The detachment of a slab separates the dense oceanic plate from the buoyant
orogenic root leading to a rebound. Eduction may therefore be partly responsible
for exhumation of high pressure rocks, late orogenic extension, and topographic
uplift. We employ two-dimensional thermomechanical modelling to investigate the
main features of plate eduction. The results show that eduction can cause a near
adiabatic decompression of the subducted crust (- 2 GPa) in a timespan of 5 My, large
extensional strain in the subduction channel, flattening of the slab, and a surface uplift
associated to orogenic extension. In order to further investigate the forces involved in
the eduction process and derive specific scaling laws, we ran several parametric
studies using a simplified setup. This experiment showed that eduction is a plausible
mechanism if the viscosity of the asthenospheric mantle is lower than 1022 Pa.s while
subduction channel viscosity does not exceed 1021 Pa.s. We suggest that eduction
can be a viable mechanism and may play an important role in orogenic evolution. |
|
|
|
|
|
|