Geodynamical Models for Continental Delamination and Ocean Lithosphere Peel Away in an Orogenic Setting


Göğüş O. H., Pysklywec R. N., Faccenna C.

ACTIVE GLOBAL SEISMOLOGY: NEOTECTONICS AND EARTHQUAKE POTENTIAL OF THE EASTERN MEDITERRANEAN REGION, cilt.225, ss.121-139, 2017 (Hakemli Dergi) identifier

Özet

A synthesis of geological, geophysical, and petrological interpretations are used to infer that a portion of the lithosphere may have been removed from beneath the crust of several orogenic regions. Lithosphere delamination and ocean slab peel away under accretionary prisms are used to account for such interpretations, nevertheless the surface evolution of this process during orogenic deformation is not well understood. In this work, we quantify the response to delamination by using numerical and laboratory experiments. Numerical model predictions show that the lithospheric delamination is associated with broad surface uplift as a result of mantle upwelling, controlled by thermal and isostatic effects. The numerical results may satisfy geological and geophysical observations for the eastern Anatolia uplift that occurred in the last 13-15 m.y. Numerical experiments demonstrate that the downgoing slab may produce subsidence over the crust in response to the migration of the lithosphere. The surface uplift may increase with higher plate convergence, therefore shortening. Laboratory-based experiments show that slower plate convergence with retreating ocean lithosphere subduction can develop into delamination type slab loss, whereas, for the experiments with higher plate convergence, the crust above the consumed mantle lithosphere becomes accreted on the retroplate similar to flake tectonics.