Stagnant slabs in the upper and lower mantle transition region

Reviews of Geophysics - Tập 39 Số 3 - Trang 291-323 - 2001
Yoshio Fukao, Sri Widiyantoro, Masayuki Obayashi

Tóm tắt

We made a region‐by‐region examination of subducted slab images along the circum‐Pacific for some of the recent global mantle tomographic models, specifically for two high‐resolution P velocity models and two long‐wavelength S velocity models. We extracted the slab images that are most consistent among different models. We found that subducted slabs tend to be subhorizontally deflected or flattened in the upper and lower mantle transition region, the depth range of which corresponds roughly to the Bullen transition region (400–1000 km). The deflected or flattened slabs reside at different depths, either above or across the 660‐km discontinuity as in Chile Andes, Aleutian, Southern Kurile, Japan, and Izu‐Bonin; slightly below the discontinuity as in Northern Kurile, Mariana, and Philippine; or well below it as in Peru Andes, Java, and Tonga‐Kermadec. There is little indication for most of these slabs to continue “directly” to greater depths well beyond the transition region. Mantle downflow associated with present slab subduction appears to be blocked strongly to turn into predominantly horizontal flow in the transition region. Recent global tomographic models show also a group of lithospheric slabs deeply sinking through the lower mantle, typically the presumed Farallon slab beneath North and Central America and the presumed Indian (Tethys) slab beneath Himalaya and the Bay of Bengal. These remnant slabs are not connected to the surface plates or to the presently subducting slabs and appear to sink independently from the latter. The presence of these deeply sinking slabs implies that the pre‐Eocene subduction occurred in much the same way as in the present day to accumulate slab bodies in the transition region and that the consequent unstable downflow occurred extensively through the transition region in the Eocene epoch to detach many of the surface plates from the subducted slabs at depths and hence to cause the reorganization of global plate motion.

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Tài liệu tham khảo

10.1029/93JB03107

10.1029/93GL01265

10.1029/JB084iB11p06297

10.1016/0040-1951(88)90272-7

10.1029/93GL02691

10.1029/98JB02467

10.1002/rog.1991.29.s2.783

10.1029/94JB00462

10.1029/JZ057i002p00227

10.1029/1999JB900166

10.1029/97JB01357

Bullen B., 1963, Introduction to the Theory of Seismology

10.1126/science.280.5360.91

10.1029/1999JB900377

10.1029/1999JB900150

10.1016/S0012-821X(98)00244-1

10.1029/97GL02054

10.1016/0012-821X(82)90190-X

10.1029/94RG01874

10.1029/JB082i014p01967

Christensen U. R., 1989, Mantle Convection, Plate Tectonics and Global Dynamics, 595

10.1016/S0012-821X(97)00192-1

10.1029/JB089iB06p04389

10.1029/JB090iB12p10291

10.1029/96GL03917

10.1016/0031-9201(94)03003-2

10.1029/94JB02130

10.1029/JB089iB07p05929

10.1016/0031-9201(81)90046-7

10.1111/j.1365-246X.1976.tb00271.x

10.1029/JB092iB13p13855

10.1029/95GL02013

10.1785/BSSA0880030722

Engebretson D. C., 1992, 180 million years of subduction, GSA Today, 2, 93

10.1029/97JB03212

10.1029/1999GL900036

10.1111/j.1365-246X.1975.tb00631.x

10.1029/97JB01276

10.1029/GM072p0135

10.1029/94JB01467

10.1029/91JB02749

10.5575/geosoc.100.4

10.1046/j.1365-246x.2000.00122.x

10.1029/JB091iB12p12389

10.1029/94JB00042

Grand S. P., 1997, Global seismic tomography: A snapshot of convection in the Earth, GSA Today, 7, 1

Gutenberg B., 1959, Physics of the Earth's Interior

10.1016/0040-1951(95)00038-0

10.1126/science.259.5099.1308

10.1016/0031-9201(90)90236-Q

10.1029/JB094iB08p10637

10.1029/JZ072i024p06309

10.1126/science.261.5127.1427

10.1029/GL015i008p00828

10.1029/97JB02565

10.1126/science.283.5409.1888

10.1029/93GL01767

10.1038/371301a0

10.1111/j.1365-246X.1995.tb03540.x

10.1029/98JB00150

10.1016/S0012-821X(97)81843-2

10.1111/j.1365-246X.1995.tb06831.x

10.1146/annurev.ea.22.050194.000341

10.1111/j.1365-246X.1995.tb06850.x

10.1029/97JB02346

Levi B. G., 1997, Earth's upper mantle: How low can it flow?, Phys. Today, 50, 17, 10.1063/1.881853

10.1029/96JB01306

10.1029/90JB02009

10.1029/97RG02282

10.1038/350055a0

10.1016/0031-9201(94)05075-9

10.1098/rsta.1996.0054

10.1086/649658

10.1029/94RG00099

10.1126/science.200.4348.1379

10.1029/JZ070i018p04633

10.1029/97GL00216

10.1016/0021-9991(85)90075-0

Obayashi M., 1997, International Symposium on New Images of the Earth's Interior Through Long‐Term Ocean‐Floor Observations, 29

10.1016/S0031-9201(96)03244-X

10.1016/S0031-9201(98)00116-2

10.1029/98GL00644

10.1145/355984.355989

10.1029/95JB01078

10.1029/98JB01668

10.1029/91GL02951

10.1029/92GL02961

10.1016/0040-1951(93)90230-H

10.1029/93GL02934

10.1029/96JB03625

Resovsky J. S., 1999, A degree 8 mantle shear velocity model from normal mode observations below 3 mHz, J. Geophys. Res., 104, 993, 10.1029/1998JB900025

10.1029/91JB01486

10.1016/0031-9201(94)05058-9

10.1038/331131a0

10.1029/94RG03020

10.1111/j.1365-246X.1995.tb06663.x

10.1029/96JB01905

10.1016/0012-821X(78)90069-9

10.1016/0040-1951(88)90263-6

10.1029/1999GL900203

10.1126/science.264.5164.1445

10.1016/0040-1951(88)90259-4

10.1016/0040-1951(84)90008-8

10.1111/j.1365-246X.1993.tb01499.x

10.1038/355791a0

10.1029/93JB02168

10.1029/94JB00730

10.1029/JB079i017p02557

10.1111/j.1365-246X.1975.tb05891.x

10.1029/GL016i010p01097

10.1016/0031-9201(93)90142-V

10.1016/0031-9201(94)05067-8

10.1029/97JB00550

10.1016/S0031-9201(96)03236-0

10.1029/93JB03408

10.1029/95RG00291

10.1029/95JB00318

10.1038/361699a0

10.1029/94JB00853

10.1029/95GL03314

10.1029/98JB00752

10.1186/BF03352190

10.1016/S0031-9201(99)00038-2

10.1111/j.1365-246X.1990.tb00688.x

10.4294/jpe1952.38.493

10.1111/j.1365-246X.1997.tb00591.x

10.1038/375777a0

10.1016/0040-1951(95)00106-9

10.1038/374154a0

10.1111/j.1365-246X.1991.tb04610.x

10.1016/0012-821X(93)90253-6

10.1029/GL016i010p01093

10.1038/353037a0

10.1111/j.1365-246X.1993.tb05603.x

10.1038/386578a0

10.1029/GD028p0005

10.1038/386266a0

10.1038/16686

10.1016/S0012-821X(99)00131-4

10.1029/97JB02623

10.1029/96GL01261

10.1186/BF03352193

10.1098/rsta.1987.0009

10.1016/0012-821X(95)00064-J

10.1016/S0031-9201(96)03162-7

Widiyantoro S. Studies of seismic tomography on regional and global scale Ph.D. thesis Aust. Natl. Univ. Canberra A.C.T. Australia 1997.

10.1126/science.271.5255.1566

10.1111/j.1365-246X.1997.tb00996.x

10.1186/BF03352194

10.1029/JB089iB07p05953

10.1029/GM074p0089

10.1126/science.278.5336.254

10.1029/GL015i012p01425

10.1016/0031-9201(90)90106-8

10.1029/96JB02487

10.1029/JB095iB05p06829

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Reviews of Geophysics

Tập 39 Số 3

291-323

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