TY - JOUR

T1 - Plume-Induced Subduction Initiation: Single-Slab or Multi-Slab Subduction?

AU - Baes, M.

AU - Sobolev, S.

AU - Gerya, T.

AU - Brune, S.

N1 - Funding Information: This work has been funded by the German Science Foundation (DFG) (Project BR 5815/1-1). The computational resources were provided by the North German Supercomputing Alliance (HLRN). The data regarding experiments in this study have been provided in GFZ data services (https://webmail.gfz-potsdam.de/Redirect/5292A2DA/doi.org/10.5880/GFZ.2.5.2019.002).

PY - 2020/2/12

Y1 - 2020/2/12

N2 - Initiation of subduction following the impingement of a hot buoyant mantle plume is one of the few scenarios that allow breaking the lithosphere and recycling a stagnant lid without requiring any preexisting weak zones. Here, we investigate factors controlling the number and shape of retreating subducting slabs formed by plume-lithosphere interaction. Using 3-D thermomechanical models we show that the deformation regime, which defines formation of single-slab or multi-slab subduction, depends on several parameters such as age of oceanic lithosphere, thickness of the crust and large-scale lithospheric extension rate. Our model results indicate that on present-day Earth multi-slab plume-induced subduction is initiated only if the oceanic lithosphere is relatively young (<30–40 Myr, but >10 Myr), and the crust has a typical thickness of 8 km. In turn, development of single-slab subduction is facilitated by older lithosphere and pre-imposed extensional stresses. In early Earth, plume-lithosphere interaction could have led to formation of either episodic short-lived circular subduction when the oceanic lithosphere was young or to multi-slab subduction when the lithosphere was old.

AB - Initiation of subduction following the impingement of a hot buoyant mantle plume is one of the few scenarios that allow breaking the lithosphere and recycling a stagnant lid without requiring any preexisting weak zones. Here, we investigate factors controlling the number and shape of retreating subducting slabs formed by plume-lithosphere interaction. Using 3-D thermomechanical models we show that the deformation regime, which defines formation of single-slab or multi-slab subduction, depends on several parameters such as age of oceanic lithosphere, thickness of the crust and large-scale lithospheric extension rate. Our model results indicate that on present-day Earth multi-slab plume-induced subduction is initiated only if the oceanic lithosphere is relatively young (<30–40 Myr, but >10 Myr), and the crust has a typical thickness of 8 km. In turn, development of single-slab subduction is facilitated by older lithosphere and pre-imposed extensional stresses. In early Earth, plume-lithosphere interaction could have led to formation of either episodic short-lived circular subduction when the oceanic lithosphere was young or to multi-slab subduction when the lithosphere was old.

KW - multi-slab

KW - numerical model

KW - plume

KW - singleslab

KW - subduction zone

UR - http://www.scopus.com/inward/record.url?scp=85080044924&partnerID=8YFLogxK

U2 - 10.1029/2019GC008663

DO - 10.1029/2019GC008663

M3 - Article

VL - 21

JO - Geochemistry, Geophysics, Geosystems

JF - Geochemistry, Geophysics, Geosystems

SN - 1525-2027

IS - 2

M1 - e2019GC008663

ER -