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| Titel |
Geodynamic modelling of terrane accretion, subduction, and collision |
| VerfasserIn |
Joya Tetreault, Susanne Buiter |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250041659
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| Zusammenfassung |
| Accretion, subduction, or collision of terranes can significantly
affect subduction zone evolution and lead to reversed subduction
polarity, trench jumping, or breaking off the slab. Terranes such as
oceanic plateaus, volcanic arcs, and continental fragments have
relatively thick crusts, and their size and buoyancy can therefore can
be expected to influence subduction dynamics. Geological observations
point out that accretion of terranes can lead to continental growth or
accretionary orogenesis as evident by the collage of allochthonous
terranes composing the western North American margin. Alternatively,
subduction of terranes, as in the Andean subduction zone, has been
posited to lead to flat slab subduction.
We examine basic models of subduction zones to define the controlling
parameters in accretion, subduction, or collision of such terranes with
the thermo-mechanical numerical code SULEC. SULEC is a 2-D, Arbitrary
Lagrangian-Eulerian, finite element code that incorporates a free
surface and a visco-elasto-plastic rheology. Our models test the
buoyancy of three end-member terranes; oceanic plateaus, volcanic arcs,
and continental fragments by varying terrane length, terrane crustal
thickness, and terrane rheology. We seek to evaluate whether terrane
buoyancy is enough to induce subduction zone rearrangement or if another
variable, such as terrane crustal detachment or a thick subduction
accretionary channel, are necessary. |
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