 |
| Titel |
The dynamics of laterally variable subductions: laboratory models applied to the Hellenides |
| VerfasserIn |
B. Guillaume, L. Husson, F. Funiciello, C. Faccenna |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1869-9510
|
| Digitales Dokument |
URL |
| Erschienen |
In: Solid Earth ; 4, no. 2 ; Nr. 4, no. 2 (2013-07-10), S.179-200 |
| Datensatznummer |
250017782
|
| Publikation (Nr.) |
 copernicus.org/se-4-179-2013.pdf |
|
|
|
|
|
| Zusammenfassung |
| We designed three-dimensional dynamically self-consistent laboratory
models of subduction to analyse the relationships between overriding plate deformation and subduction dynamics in the upper mantle.
We investigated the effects of the
subduction of a lithosphere of laterally variable buoyancy on the
temporal evolution of trench kinematics and shape, horizontal flow at
the top of the asthenosphere, dynamic topography and deformation of
the overriding plate.
Two subducting units, which correspond to a negatively buoyant oceanic plate and positively
buoyant continental one, are juxtaposed via a trench-perpendicular interface (analogue to a tear fault) that is either fully-coupled or shear-stress free.
Differential rates of trench retreat, in excess of 6 cm yr−1 between the
two units, trigger a more vigorous mantle flow above the oceanic slab
unit than above the continental slab unit. The resulting asymmetrical
sublithospheric flow shears the overriding plate in front of the tear
fault, and deformation gradually switches from extension to
transtension through time.
The consistency between our models results and geological observations
suggests that the Late Cenozoic deformation of the Aegean domain,
including the formation of the North Aegean Trough and Central
Hellenic Shear zone, results from the spatial variations in the
buoyancy of the subducting lithosphere.
In particular, the lateral changes of the subduction regime caused by
the Early Pliocene subduction of the old oceanic Ionian plate
redesigned mantle flow and excited an increasingly vigorous dextral
shear underneath the overriding plate. The models suggest that it is
the inception of the Kefalonia Fault that caused the transition
between an extension dominated tectonic regime to transtension, in the
North Aegean, Mainland Greece and Peloponnese. The subduction of the
tear fault may also have helped the propagation of the North Anatolian
Fault into the Aegean domain. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|