俯冲初始时板块分界面形状对俯冲过程的影响
|
摘要
自板块理论建立以来,俯冲一直是学者们关心的热点问题.前人结合地质、地球物理、实验室物理实验和数值模拟等多种手段对这一问题进行了大量的研究.以往的研究更为关注俯冲过程中板块的作用、地幔流动的规律和物质的迁移与相变等问题,却常忽视了俯冲是如何开始的这一基本问题.同时,由于相关数据资料较为有限,更限制了俯冲启动的相关研究.因此,本文选取俯冲启动问题中板块分界面形状对俯冲过程的影响这一问题,使用有限元的方法进行了数值模拟.我们选择针对倾斜型、垂直型和弯曲型三种不同形状的板块分界面建立对比模型,比较它们演化至10Ma的过程我们发现:分界面几何形状的不同的确会对俯冲板块演化和海沟的深度产生影响.倾斜型模型的俯冲角度最大,海沟深度最深,俯冲深度最深;垂直型模型的俯冲角度和海沟深度仅次于倾斜型模型,俯冲深度最浅;弯曲型模型的俯冲角度最小,海沟深度最小,俯冲的深度介于倾斜型和垂直型之间.结合以上结论不难看出,俯冲角和海沟深度变化具有一定的相关性,俯冲角度越大,相应的海沟深度越大.
Subduction is one of focused issues since the establishment of the plate tectonics theory.In combination of geology,geophysics,laboratory physics experiments and numerical simulations,agreat deal of studies on this topic have been conducted.Most of previous work focus on the aspects of plates,mantle flow,motion and phase transition of materials during subduction,while one basic question how subduction begins remains unsolved.Meanwhile,due to the lack of data,the study of this problem,if any,is limited.In this paper,we choose three kinds of interface geometry,using finite element numerical models to simulate subduction.What we want to see here is whether and how the interface geometry of a plate affects subduction evolution.We build three kinds of models with different initial geometries,"dipping","vertical"and "bending".The results show that the plate interface geometry has an effect both on thesubducting plate and the trench depth.In the"dipping"model,subduction angle is the biggest,and both the subducting and trench depths are also the largest.The subducting angle and the trench depth in the"vertical"model are smaller only than those in the"dipping"model and the subducting depth is the smallest.The "bending"model has the smallest subducting angle and trench depth,but has a intermediate subducting depth in the three cases.It seems that there is a relationship between subducting angle and trench depth,that is,when subducting angle gets larger,the trench becomes deeper correspondingly.
Subduction is one of focused issues since the establishment of the plate tectonics theory.In combination of geology,geophysics,laboratory physics experiments and numerical simulations,agreat deal of studies on this topic have been conducted.Most of previous work focus on the aspects of plates,mantle flow,motion and phase transition of materials during subduction,while one basic question how subduction begins remains unsolved.Meanwhile,due to the lack of data,the study of this problem,if any,is limited.In this paper,we choose three kinds of interface geometry,using finite element numerical models to simulate subduction.What we want to see here is whether and how the interface geometry of a plate affects subduction evolution.We build three kinds of models with different initial geometries,"dipping","vertical"and "bending".The results show that the plate interface geometry has an effect both on thesubducting plate and the trench depth.In the"dipping"model,subduction angle is the biggest,and both the subducting and trench depths are also the largest.The subducting angle and the trench depth in the"vertical"model are smaller only than those in the"dipping"model and the subducting depth is the smallest.The "bending"model has the smallest subducting angle and trench depth,but has a intermediate subducting depth in the three cases.It seems that there is a relationship between subducting angle and trench depth,that is,when subducting angle gets larger,the trench becomes deeper correspondingly.
引文
Arcay D,Lallemand S,Doin M P.2008.Back-arc strain in subduction zones:Statistical observations versus numerical modeling.Geochemistry,Geophysics,Geosystems,9(5):Q05015,doi:10.1029/2007GC001875.
Billen M I,Gurnis M.2001.A low viscosity wedge in subduction zones.Earth and Planetary Science Letters,193(1-2):227-236,doi:10.1016/S0012-821X(01)00482-4.
Billen M I,Hirth G.2005.Newtonian versus non-Newtonian upper mantle viscosity:Implications for subduction initiation.Geophysical Research Letters,32(19):312-321,L19304,doi:10.1029/2005GL023457.
Buiter S,Ellis S.2016.A discussion of numerical subduction initiation.∥EGU General Assembly Conference.Vienna Austria:EGU General Assembly.
Chapman D S.1986.Thermal gradients in the continental crust.Geological Society,London,Special Publications,24(1):63-70,doi:10.1144/GSL.SP.1986.024.01.07.
Cloetingh S,Wortel R,Vlaar N J.1989.On the initiation of subduction zones.Pure and Applied Geophysics,129(1-2):7-25,doi:10.1007/BF00874622.
Cloos M.1993.Lithospheric buoyancy and collisional orogenesis:subduction of oceanic plateaus,continental margins,island arcs,spreading ridges,and seamounts.GSA Bulletin,105(6):715-737,doi:10.1130/0016-7606(1993)105<0715:LBACOS>2.3.CO;2.
Ekstr9m G,Nettles M,Dziewonski A M.2012.The global CMTproject 2004-2010:Centroid-moment tensors for 13,017earthquakes.Physics of the Earth and Planetary Interiors,200-201:1-9,doi:10.1016/j.pepi.2012.04.002.
Forsyth D,Uyeda S.1975.On the relative importance of the driving forces of plate motion.Geophysical Journal International,43(1):163-200,doi:10.1111/j.1365-246X.1975.tb00631.x.
Fukao Y,Obayashi M.2013.Subducted slabs stagnant above,penetrating through,and trapped below the 660km discontinuity.Journal of Geophysical Research:Solid Earth,118(11):5920-5938,doi:10.1002/2013JB010466.
Gerya T,Stern R J,Baes M,et al.2014.Dynamics and significance of plume-induced subduction initiation:Numerical modeling.∥American Geophysical Union,Fall Meeting 2014.San Francisco,CA:AGU.
Gleason G C,Tullis J.1995.A flow law for dislocation creep of quartz aggregates determined with the molten salt cell.Tectonophysics,247(1-4):1-23,doi:10.1016/0040-1951(95)00011-B.
Hall C E,Gurnis M,Sdrolias M,et al.2003.Catastrophic initiation of subduction following forced convergence across fracture zones.Earth and Planetary Science Letters,212(1):15-30,doi:10.1016/S0012-821X(03)00242-5.
Han P,Wei D P,Zhang K L,et al.2016.Lattice-Preferred orientations of olivine in subducting oceanic lithosphere derived from the observed seismic anisotropies in double seismic zones.Earthquake Science,29(4):243-258,doi:10.1007/s11589-016-0160-5.
Hirth G,Kohlstedt D L.2013.Rheology of the upper mantle and the mantle wedge:A view from the experimentalists.∥Eiler J.Inside the Subduction Factory.Washington D C:American Geophysical Union,83-105,doi:10.1029/138GM06.
Holt A F,Buffett B A,Becker T W.2015.Overriding plate thickness control on subducting plate curvature.Geophysical Research Letters,42(10):3802-3810,doi:10.1002/2015GL063834.
Huang J L,Zhao D P.2006.High-resolution mantle tomography of China and surrounding regions.Journal of Geophysical Research:Solid Earth,111(B9):4813-4825,B09305,doi:10.1029/2005JB004066.
Jadamec M A,Billen M I,Roeske S M.2013.Three-dimensional numerical models of flat slab subduction and the Denali fault driving deformation in south-central Alaska.Earth and Planetary Science Letters,376:29-42,doi:10.1016/j.epsl.2013.06.009.
Jarrard R D.1986.Relations among subduction parameters.Reviews of Geophysics,24(2):217-284,doi:10.1029/RG024i002p00217.
Karato S I,Wu P.1993.Rheology of the upper mantle:A synthesis.Science,260(5109):771-778,doi:10.1126/science.260.5109.771.
Karato S I,Jung H.2003.Effects of pressure on high-temperature dislocation creep in olivine.Philosophical Magazine,83(3):401-414,doi:10.1080/0141861021000025829.
Karig D E.1982.Initiation of subduction zones:Implications for arc evolution and ophiolite development.Geological Society,London,Special Publications,10(1):563-576,doi:10.1144/GSL.SP.1982.010.01.37.
Kronbichler M,Heister T,Bangerth W.2012.High accuracy mantle convection simulation through modern numerical methods.Geophysical Journal International,191(1):12-29,doi:10.1111/j.1365-246X.2012.05609.x.
Lallemand S,Heuret A,Boutelier D.2005.On the relationships between slab dip,back-arc stress,upper plate absolute motion,and crustal nature in subduction zones.Geochemistry,Geophysics,Geosystems,6(9):Q09006,doi:10.1029/2005GC000917.
Leng W,Gurnis M.2011.Dynamics of subduction initiation with different evolutionary pathways.Geochemistry,Geophysics,Geosystems,12(12):Q12018,doi:10.1029/2011GC003877.
Leng W,Gurnis M.2015.Subduction initiation at relic arcs.Geophysical Research Letters,42(17):7014-7021,doi:10.1002/2015GL064985.
Liu M X,Wei D P,Shi Y N.2017.Review on the opening and evolution models of the Japan Sea.Progress in Geophysics(in Chinese),32(6):2341-2352,doi:10.6038/pg20170608.
Marques F O,Kaus B J P.2016.Speculations on the impact of catastrophic subduction initiation on the earth system.Journal of Geodynamics,93:1-16,doi:10.1016/j.jog.2015.09.003.
Naliboff J,Buiter S J H.2015.Rift reactivation and migration during multiphase extension.Earth and Planetary Science Letters,421:58-67,doi:10.1016/j.epsl.2015.03.050.
Nikolaeva K,Gerya T,Marques F O.2008.Numerical modelling of subduction initiation at passive margins.AGU Fall Meeting.AGUFall Meeting Abstracts.
Nikolaeva K,Gerya T V,Marques F O.2010.Subduction initiation at passive margins:Numerical modeling.Journal of Geophysical Research:Solid Earth,115(B3):B03406,doi:10.1029/2009JB006549.
Niu Y,O′Hara M J,Pearce J A.2003.Initiation of subduction zones as a consequence of lateral compositional buoyancy contrast within the lithosphere:A petrological perspective.Journal of Petrology,44(11):764-778,doi:10.1093/petrology/44.5.851.
Ranalli G.1995.Rheology of the Earth.2nd ed.London:Chapman&Hall.
Riel N,Capitanio F A,Velic M.2017.Numerical modeling of stress and topography coupling during subduction:Inferences on global vs.regional observables interpretation.Tectonophysics,746:239-250,doi:10.1016/j.tecto.2017.07.023.
Rybacki E,Gottschalk M,Wirth R,et al.2006.Influence of water fugacity and activation volume on the flow properties of finegrained anorthite aggregates.Journal of Geophysical Research:Solid Earth,111(B3):B03203,doi:10.1029/2005JB003663.
Savage M K.1999.Seismic anisotropy and mantle deformation:What have we learned from shear wave splitting?.Reviews of Geophysics,37(1):65-106,doi:10.1029/98RG02075.
Schellart W P,Moresi L.2013.A new driving mechanism for backarc extension and backarc shortening through slab sinking induced toroidal and poloidal mantle flow:Results from dynamic subduction models with an overriding plate.Journal of Geophysical Research:Solid Earth,118(6):3221-3248,doi:10.1002/jgrb.50173.
Sdrolias M,Müller R D.2006.Controls on back-arc basin formation.Geochemistry,Geophysics,Geosystems,7(4):Q04016,doi:10.1029/95JB01869.
Shi Y N,Wei D P,Li Z H,et al.2017.Subduction mode selection
during slab and mantle transition zone interaction:Numerical modeling.Pure and Applied Geophysics,175(2):529-548,doi:10.1007/s00024-017-1762-0.
Stern R J.2004.Subduction initiation:Spontaneous and induced.Earth and Planetary Science Letters,226(3-4):275-292,doi:10.1016/j.epsl.2004.08.007.
Tetreault J L,Buiter S J H.2012.Geodynamic models of terrane accretion:Testing the fate of island arcs,oceanic plateaus,and continental fragments in subduction zones.Journal of Geophysical Research:Solid Earth,117(B8):B08403,doi:10.1029/2012JB009316.
Toth J,Gurnis M.1998.Dynamics of subduction initiation at preexisting fault zones.Journal of Geophysical Research:Solid Earth,103(B8):18053-18067,doi:10.1029/98JB01076.
Turcotte D L,Schubert G.2014.Geodynamics.Cambridge:Cambridge University Press.
Wessel P,Smith W H F.2017.The Generic Mapping Tools(GMT)4.5.0Technical Reference and Cookbook.16,227.
Wilks K R,Carter N L.1990.Rheology of some continental lower crustal rocks.Tectonophysics,182(1-2):57-77,doi:10.1016/0040-1951(90)90342-6.
Zhang K L,Wei D P.2011.A kinematic thermal model for descending slabs with velocity boundary layers:A case study for the Tonga Subducting slab.Acta Geologica Sinica,85(1):211-222,doi:10.1111/j.1755-6724.2011.00391.x.
Zhang K L,Wei D P.2011.On the influence factors of double seismic zones.Chinese Journal of Geophysics(in Chinese),54(11):2838-2850,doi:10.3969/j.issn.0001-5733.2011.11.014.
Zhang K L,Wei D P.2012.Correlation between plate age and layer separation of double seismic zones.Earthquake Science,25(1):95-101,doi:10.1007/s11589-012-0835-5.
Zhong S J,Gurnis M.1994.Controls on trench topography from dynamic models of subducted slabs.Journal of Geophysical Research:Solid Earth,99(B8):15683-15695.
刘梦雪,魏东平,史亚男.2017.日本海的形成与演化模式综述.地球物理学进展,32(6):2341-2352,doi:10.6038/pg20170608.
张克亮,魏东平.2011.双地震带的影响因素探讨.地球物理学报,54(11):2838-2850,doi:10.3969/j.issn.0001-5733.2011.11.014.
Billen M I,Gurnis M.2001.A low viscosity wedge in subduction zones.Earth and Planetary Science Letters,193(1-2):227-236,doi:10.1016/S0012-821X(01)00482-4.
Billen M I,Hirth G.2005.Newtonian versus non-Newtonian upper mantle viscosity:Implications for subduction initiation.Geophysical Research Letters,32(19):312-321,L19304,doi:10.1029/2005GL023457.
Buiter S,Ellis S.2016.A discussion of numerical subduction initiation.∥EGU General Assembly Conference.Vienna Austria:EGU General Assembly.
Chapman D S.1986.Thermal gradients in the continental crust.Geological Society,London,Special Publications,24(1):63-70,doi:10.1144/GSL.SP.1986.024.01.07.
Cloetingh S,Wortel R,Vlaar N J.1989.On the initiation of subduction zones.Pure and Applied Geophysics,129(1-2):7-25,doi:10.1007/BF00874622.
Cloos M.1993.Lithospheric buoyancy and collisional orogenesis:subduction of oceanic plateaus,continental margins,island arcs,spreading ridges,and seamounts.GSA Bulletin,105(6):715-737,doi:10.1130/0016-7606(1993)105<0715:LBACOS>2.3.CO;2.
Ekstr9m G,Nettles M,Dziewonski A M.2012.The global CMTproject 2004-2010:Centroid-moment tensors for 13,017earthquakes.Physics of the Earth and Planetary Interiors,200-201:1-9,doi:10.1016/j.pepi.2012.04.002.
Forsyth D,Uyeda S.1975.On the relative importance of the driving forces of plate motion.Geophysical Journal International,43(1):163-200,doi:10.1111/j.1365-246X.1975.tb00631.x.
Fukao Y,Obayashi M.2013.Subducted slabs stagnant above,penetrating through,and trapped below the 660km discontinuity.Journal of Geophysical Research:Solid Earth,118(11):5920-5938,doi:10.1002/2013JB010466.
Gerya T,Stern R J,Baes M,et al.2014.Dynamics and significance of plume-induced subduction initiation:Numerical modeling.∥American Geophysical Union,Fall Meeting 2014.San Francisco,CA:AGU.
Gleason G C,Tullis J.1995.A flow law for dislocation creep of quartz aggregates determined with the molten salt cell.Tectonophysics,247(1-4):1-23,doi:10.1016/0040-1951(95)00011-B.
Hall C E,Gurnis M,Sdrolias M,et al.2003.Catastrophic initiation of subduction following forced convergence across fracture zones.Earth and Planetary Science Letters,212(1):15-30,doi:10.1016/S0012-821X(03)00242-5.
Han P,Wei D P,Zhang K L,et al.2016.Lattice-Preferred orientations of olivine in subducting oceanic lithosphere derived from the observed seismic anisotropies in double seismic zones.Earthquake Science,29(4):243-258,doi:10.1007/s11589-016-0160-5.
Hirth G,Kohlstedt D L.2013.Rheology of the upper mantle and the mantle wedge:A view from the experimentalists.∥Eiler J.Inside the Subduction Factory.Washington D C:American Geophysical Union,83-105,doi:10.1029/138GM06.
Holt A F,Buffett B A,Becker T W.2015.Overriding plate thickness control on subducting plate curvature.Geophysical Research Letters,42(10):3802-3810,doi:10.1002/2015GL063834.
Huang J L,Zhao D P.2006.High-resolution mantle tomography of China and surrounding regions.Journal of Geophysical Research:Solid Earth,111(B9):4813-4825,B09305,doi:10.1029/2005JB004066.
Jadamec M A,Billen M I,Roeske S M.2013.Three-dimensional numerical models of flat slab subduction and the Denali fault driving deformation in south-central Alaska.Earth and Planetary Science Letters,376:29-42,doi:10.1016/j.epsl.2013.06.009.
Jarrard R D.1986.Relations among subduction parameters.Reviews of Geophysics,24(2):217-284,doi:10.1029/RG024i002p00217.
Karato S I,Wu P.1993.Rheology of the upper mantle:A synthesis.Science,260(5109):771-778,doi:10.1126/science.260.5109.771.
Karato S I,Jung H.2003.Effects of pressure on high-temperature dislocation creep in olivine.Philosophical Magazine,83(3):401-414,doi:10.1080/0141861021000025829.
Karig D E.1982.Initiation of subduction zones:Implications for arc evolution and ophiolite development.Geological Society,London,Special Publications,10(1):563-576,doi:10.1144/GSL.SP.1982.010.01.37.
Kronbichler M,Heister T,Bangerth W.2012.High accuracy mantle convection simulation through modern numerical methods.Geophysical Journal International,191(1):12-29,doi:10.1111/j.1365-246X.2012.05609.x.
Lallemand S,Heuret A,Boutelier D.2005.On the relationships between slab dip,back-arc stress,upper plate absolute motion,and crustal nature in subduction zones.Geochemistry,Geophysics,Geosystems,6(9):Q09006,doi:10.1029/2005GC000917.
Leng W,Gurnis M.2011.Dynamics of subduction initiation with different evolutionary pathways.Geochemistry,Geophysics,Geosystems,12(12):Q12018,doi:10.1029/2011GC003877.
Leng W,Gurnis M.2015.Subduction initiation at relic arcs.Geophysical Research Letters,42(17):7014-7021,doi:10.1002/2015GL064985.
Liu M X,Wei D P,Shi Y N.2017.Review on the opening and evolution models of the Japan Sea.Progress in Geophysics(in Chinese),32(6):2341-2352,doi:10.6038/pg20170608.
Marques F O,Kaus B J P.2016.Speculations on the impact of catastrophic subduction initiation on the earth system.Journal of Geodynamics,93:1-16,doi:10.1016/j.jog.2015.09.003.
Naliboff J,Buiter S J H.2015.Rift reactivation and migration during multiphase extension.Earth and Planetary Science Letters,421:58-67,doi:10.1016/j.epsl.2015.03.050.
Nikolaeva K,Gerya T,Marques F O.2008.Numerical modelling of subduction initiation at passive margins.AGU Fall Meeting.AGUFall Meeting Abstracts.
Nikolaeva K,Gerya T V,Marques F O.2010.Subduction initiation at passive margins:Numerical modeling.Journal of Geophysical Research:Solid Earth,115(B3):B03406,doi:10.1029/2009JB006549.
Niu Y,O′Hara M J,Pearce J A.2003.Initiation of subduction zones as a consequence of lateral compositional buoyancy contrast within the lithosphere:A petrological perspective.Journal of Petrology,44(11):764-778,doi:10.1093/petrology/44.5.851.
Ranalli G.1995.Rheology of the Earth.2nd ed.London:Chapman&Hall.
Riel N,Capitanio F A,Velic M.2017.Numerical modeling of stress and topography coupling during subduction:Inferences on global vs.regional observables interpretation.Tectonophysics,746:239-250,doi:10.1016/j.tecto.2017.07.023.
Rybacki E,Gottschalk M,Wirth R,et al.2006.Influence of water fugacity and activation volume on the flow properties of finegrained anorthite aggregates.Journal of Geophysical Research:Solid Earth,111(B3):B03203,doi:10.1029/2005JB003663.
Savage M K.1999.Seismic anisotropy and mantle deformation:What have we learned from shear wave splitting?.Reviews of Geophysics,37(1):65-106,doi:10.1029/98RG02075.
Schellart W P,Moresi L.2013.A new driving mechanism for backarc extension and backarc shortening through slab sinking induced toroidal and poloidal mantle flow:Results from dynamic subduction models with an overriding plate.Journal of Geophysical Research:Solid Earth,118(6):3221-3248,doi:10.1002/jgrb.50173.
Sdrolias M,Müller R D.2006.Controls on back-arc basin formation.Geochemistry,Geophysics,Geosystems,7(4):Q04016,doi:10.1029/95JB01869.
Shi Y N,Wei D P,Li Z H,et al.2017.Subduction mode selection
during slab and mantle transition zone interaction:Numerical modeling.Pure and Applied Geophysics,175(2):529-548,doi:10.1007/s00024-017-1762-0.
Stern R J.2004.Subduction initiation:Spontaneous and induced.Earth and Planetary Science Letters,226(3-4):275-292,doi:10.1016/j.epsl.2004.08.007.
Tetreault J L,Buiter S J H.2012.Geodynamic models of terrane accretion:Testing the fate of island arcs,oceanic plateaus,and continental fragments in subduction zones.Journal of Geophysical Research:Solid Earth,117(B8):B08403,doi:10.1029/2012JB009316.
Toth J,Gurnis M.1998.Dynamics of subduction initiation at preexisting fault zones.Journal of Geophysical Research:Solid Earth,103(B8):18053-18067,doi:10.1029/98JB01076.
Turcotte D L,Schubert G.2014.Geodynamics.Cambridge:Cambridge University Press.
Wessel P,Smith W H F.2017.The Generic Mapping Tools(GMT)4.5.0Technical Reference and Cookbook.16,227.
Wilks K R,Carter N L.1990.Rheology of some continental lower crustal rocks.Tectonophysics,182(1-2):57-77,doi:10.1016/0040-1951(90)90342-6.
Zhang K L,Wei D P.2011.A kinematic thermal model for descending slabs with velocity boundary layers:A case study for the Tonga Subducting slab.Acta Geologica Sinica,85(1):211-222,doi:10.1111/j.1755-6724.2011.00391.x.
Zhang K L,Wei D P.2011.On the influence factors of double seismic zones.Chinese Journal of Geophysics(in Chinese),54(11):2838-2850,doi:10.3969/j.issn.0001-5733.2011.11.014.
Zhang K L,Wei D P.2012.Correlation between plate age and layer separation of double seismic zones.Earthquake Science,25(1):95-101,doi:10.1007/s11589-012-0835-5.
Zhong S J,Gurnis M.1994.Controls on trench topography from dynamic models of subducted slabs.Journal of Geophysical Research:Solid Earth,99(B8):15683-15695.
刘梦雪,魏东平,史亚男.2017.日本海的形成与演化模式综述.地球物理学进展,32(6):2341-2352,doi:10.6038/pg20170608.
张克亮,魏东平.2011.双地震带的影响因素探讨.地球物理学报,54(11):2838-2850,doi:10.3969/j.issn.0001-5733.2011.11.014.