TY  - JOUR
A1  - Gerya, Taras V.
A1  - Stern, Robert J.
A1  - Baes, Marzieh
A1  - Sobolev, Stephan Vladimir
A1  - Whattam, Scott A.
T1  - Plate tectonics on the Earth triggered by plume-induced subduction initiation
JF  - Nature : the international weekly journal of science
N2  - Scientific theories of how subduction and plate tectonics began on Earth-and what the tectonic structure of Earth was before this-remain enigmatic and contentious(1). Understanding viable scenarios for the onset of subduction and plate tectonics(2,3) is hampered by the fact that subduction initiation processes must have been markedly different before the onset of global plate tectonics because most present-day subduction initiation mechanisms require acting plate forces and existing zones of lithospheric weakness, which are both consequences of plate tectonics(4). However, plume-induced subduction initiation(5-9) could have started the first subduction zone without the help of plate tectonics. Here, we test this mechanism using high-resolution three-dimensional numerical thermomechanical modelling. We demonstrate that three key physical factors combine to trigger self-sustained subduction: (1) a strong, negatively buoyant oceanic lithosphere; (2) focused magmatic weakening and thinning of lithosphere above the plume; and (3) lubrication of the slab interface by hydrated crust. We also show that plume-induced subduction could only have been feasible in the hotter early Earth for old oceanic plates. In contrast, younger plates favoured episodic lithospheric drips rather than self-sustained subduction and global plate tectonics.
Y1  - 2015
U6  - https://doi.org/10.1038/nature15752
SN  - 0028-0836
SN  - 1476-4687
VL  - 527
IS  - 7577
SP  - 221
EP  - +
PB  - Nature Publ. Group
CY  - London
ER  -