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Delamination vs. break‐off: the fate of continental collision
Author(s) -
Magni Valentina,
Faccenna Claudio,
Hunen Jeroen,
Funiciello Francesca
Publication year - 2013
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/grl.50090
Subject(s) - subduction , geology , lithosphere , mantle (geology) , delamination (geology) , crust , continental crust , collision zone , slab , geophysics , convergent boundary , continental collision , eclogitization , continental margin , petrology , oceanic crust , seismology , tectonics
The fate of a convergent continental margin is investigated. We perform a set of 2D numerical models to study how and why continental collision can evolve in different scenarios. Since the rheology of continental lithosphere has a major control on the dynamics of subduction, we explore a range of different lithosphere and lower crust viscosity values to understand their sensitivity on the possible scenarios. We find that with a rheologically layered crust both delamination and break‐off are feasible. We identify three modes: (1) slab detachment, in which the lithospheric mantle and the crust are strongly coupled, subduction slows down and the slab eventually breaks; (2) delamination of the lithospheric mantle that separates from the crust and continue to subduct and (3) an intermediate mode where the lithospheric mantle and the crust remain partially coupled, resulting in an initial stage of delamination followed by the slow down and cessation of subduction.