TY - JOUR A1 - Baes, Marzieh A1 - Sobolev, Stephan A1 - Gerya, Taras V. A1 - Brune, Sascha T1 - Plume-induced subduction initiation BT - single-slab or multi-slab subduction? JF - Geochemistry, geophysics, geosystems 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. KW - subduction zone KW - plume KW - numerical model KW - singleslab KW - multi-slab Y1 - 2020 U6 - https://doi.org/10.1029/2019GC008663 SN - 1525-2027 VL - 21 IS - 2 PB - American Geophysical Union CY - Washington ER - TY - JOUR A1 - Baes, Marzieh A1 - Sobolev, Stephan V. A1 - Gerya, Taras V. A1 - Brune, Sascha T1 - Subduction initiation by Plume-Plateau interaction BT - insights from numerical models JF - Geochemistry, geophysics, geosystems N2 - It has recently been demonstrated that the interaction of a mantle plume with sufficiently old oceanic lithosphere can initiate subduction. However, the existence of large lithospheric heterogeneities, such as a buoyant plateau, in proximity to a rising plume head may potentially hinder the formation of a new subduction zone. Here, we investigate this scenario by means of 3-D numerical thermomechanical modeling. We explore how plume-lithosphere interaction is affected by lithospheric age, relative location of plume head and plateau border, and the strength of the oceanic crust. Our numerical experiments suggest four different geodynamic regimes: (a) oceanic trench formation, (b) circular oceanic-plateau trench formation, (c) plateau trench formation, and (d) no trench formation. We show that regardless of the age and crustal strength of the oceanic lithosphere, subduction can initiate when the plume head is either below the plateau border or at a distance less than the plume radius from the plateau edge. Crustal heterogeneity facilitates subduction initiation of old oceanic lithosphere. High crustal strength hampers the formation of a new subduction zone when the plume head is located below a young lithosphere containing a thick and strong plateau. We suggest that plume-plateau interaction in the western margin of the Caribbean could have resulted in subduction initiation when the plume head impinged onto the oceanic lithosphere close to the border between plateau and oceanic crust. KW - subduction zone KW - plume KW - plateau KW - numerical modeling KW - plume-induced KW - subduction initiation (PISI) Y1 - 2020 U6 - https://doi.org/10.1029/2020GC009119 SN - 1525-2027 VL - 21 IS - 8 PB - American Geophysical Union CY - Washington ER - TY - GEN A1 - Baes, Marzieh A1 - Sobolev, Stephan Vladimir A1 - Gerya, Taras V. A1 - Brune, Sascha T1 - Plume-induced subduction initiation BT - Single-slab or multi-slab subduction? T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe 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. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1167 KW - subduction zone KW - plume KW - numerical model KW - singleslab KW - multi-slab Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-522742 SN - 1866-8372 IS - 2 ER - TY - JOUR A1 - Baes, Marzieh A1 - Gerya, Taras V. A1 - Sobolev, Stephan Vladimir T1 - 3-D thermo-mechanical modeling of plume-induced subduction initiation JF - Earth & planetary science letters N2 - Here, we study the 3-D subduction initiation process induced by the interaction between a hot thermochemical mantle plume and oceanic lithosphere using thermo-mechanical viscoplastic finite difference marker-in-cell models. Our numerical modeling results show that self-sustaining subduction is induced by plume-lithosphere interaction when the plume is sufficiently buoyant, the oceanic lithosphere is sufficiently old and the plate is weak enough to allow the buoyant plume to. pass through it. Subduction initiation occurs following penetration of the lithosphere by the hot plume and the downward displacement of broken, nearly circular segments of lithosphere (proto-slabs) as a result of partially molten plume rocks overriding the proto-slabs. Our experiments show four different deformation regimes in response to plume-lithosphere interaction: a) self-sustaining subduction initiation, in which subduction becomes self-sustaining; b) frozen subduction initiation, in which subduction stops at shallow depths; c) slab break-off, in which the subducting circular slab breaks off soon after formation; and d) plume underplating, in which the plume does not pass through the lithosphere and instead spreads beneath it (i.e., failed subduction initiation). These regimes depend on several parameters, such as the size, composition, and temperature of the plume, the brittle/plastic strength and age of the oceanic lithosphere, and the presence/absence of lithospheric heterogeneities. The results show that subduction initiates and becomes self-sustaining when the lithosphere is older than 10 Myr and the non dimensional ratio of the plume buoyancy force and lithospheric strength above the plume is higher than approximately 2. The outcomes of our numerical experiments are applicable for subduction initiation in the modern and Precambrian Earth and for the origin of plume-related corona structures on Venus. (C) 2016 Elsevier B.V. All rights reserved. KW - subduction initiation KW - mantle plume KW - oceanic lithosphere KW - numerical models Y1 - 2016 U6 - https://doi.org/10.1016/j.epsl.2016.08.023 SN - 0012-821X SN - 1385-013X VL - 453 SP - 193 EP - 203 PB - Elsevier CY - Amsterdam ER - 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 -