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| Titel |
Multiscale mantle convection along the Tethyan collisional margin |
| VerfasserIn |
Claudio Faccenna, Thorsten Becker |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250074549
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| Zusammenfassung |
| We perform global mantle circulation to reconstruct the style and geometry of mantle
convection beneath the Tethyan region, from the Mediterranean to the Hiamalayan belt. To
quantify the contribution of mantle heterogeneity and subduction zones to mantle circulation
and plate motions, we compute the instantaneous mantle flow that can be inferred from
seismic tomography when velocity anomalies are converted into temperature. Model
results are compared with geodesy, residual topography, and shear wave splitting
observations. We evaluate different boundary conditions to test the role of slab pull and
mantle convection as driving forces for the kinematics of the Tethyan system. Our
results show that mantle drag exerted on the base of the lithosphere by a large-scale,
convective “conveyor belt” with an active upwelling component is likely the main
cause for the ongoing indentation of the Indian and Arabian plates into Eurasia.
This large scale convection cell superimposed to small scale convection that could
be resolved in region such as the Mediterranean, where high resolution seismic
tomography is available. More in general, our model emphasizes that large scale mantle
convection dragging continental block against Eurasia produce the necessary kinematic
conditions to sustaine thick collisional orogen, whereas small scale convection
confined in the upper mantle produces ephemeral, slab-pull dominated, orogenic belt. |
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