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Crustal‐scale mass transfer, geotherm and topography at convergent plate boundaries
Author(s) -
Vanderhaeghe Olivier,
Duchêne Stéphanie
Publication year - 2010
Publication title -
terra nova
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.353
H-Index - 89
eISSN - 1365-3121
pISSN - 0954-4879
DOI - 10.1111/j.1365-3121.2010.00952.x
Subject(s) - geology , mantle (geology) , subduction , slab , lithosphere , crust , slab window , geothermal gradient , geophysics , continental crust , mantle convection , plate tectonics , petrology , oceanic crust , seismology , tectonics
Terra Nova, 22, 315–323, 2010 Abstract End‐member cases for the fate of the crust at convergent lithospheric plate boundaries accommodated by subduction are considered combining (i) plate kinematics (slab retreat vs. slab advance) and (ii) mechanical coupling/decoupling within the subducting slab. Slab advance is accommodated by thickening of the overriding lithospheric mantle, whereas slab retreat is associated with thinning. Crust–mantle mechanical coupling results in continental subduction, whereas decoupling leads to continental accretion. The thermal and topographic evolutions of the associated orogenic belts are functions of the crust–mantle thickness ratio resulting from the combined effects of crust–mantle coupling/decoupling and slab advance/retreat. Crustal accretion associated with slab advance results in crustal thickening and contributes to an increase in radioactive heat production and buoyancy, which is impeded by concomitant thickening of the conductive and dense lithospheric mantle. In contrast, crustal accretion combined with slab retreat results in thickening simultaneous with thinning of the lithospheric mantle. This peculiar situation is the most favourable for generating a high‐temperature and buoyant orogenic belt.