Large‐scale rigid‐body rotation in the mantle wedge and its implications for seismic tomography

American Geophysical Union (AGU) - Tập 7 Số 5 - 2006
Weronika Gorczyk1, Taras Gerya2,3, J. A. D. Connolly4, David A. Yuen5, M. L. Rudolph6
1Geological Institute Swiss Federal Institute of Technology (ETH ‐ Zürich) LEB, Leonhaedstrasse 19 CH8092 Zurich Switzerland
2Geophysical Institute Swiss Federal Institute of Technology (ETH ‐ Zürich) ETH Hoenggerberg, HPP CH8093 Zurich Switzerland
3Institute of Experimental Mineralogy, Russian Academy of Sciences, 142432 Chernogolovka, Moscow, Russia
4Geological Institute Swiss Federal Institute of Technology (ETH ‐ Zürich) Sonneggstrasse 5 CH8092 Zurich Switzerland
5Department of Geology and Geophysics University of Minnesota Minneapolis Minnesota 55455‐0219 USA
6Department of Geology, Oberlin College, Oberlin, Ohio 44074, USA

Tóm tắt

Using a combined finite difference and marker‐in‐cell technique, we performed two‐dimensional coupled petrological‐thermomechanical numerical simulations of intraoceanic subduction. The simulations indicate that parts of the mantle wedge can become trapped between rheologically weak, hydrated, and partially molten upwellings (cold plumes) and the subducting slab. The structures form at various depths and develop circular, elliptic, or irregular shapes. The combined effect of the tractions caused by upwelling and subduction causes these regions to rotate. Our simulations investigate the parameters controlling the occurrence and long‐term stability of such rigid, rotating structures. Circular rotating structures like “subduction wheels” are characteristic of models with relatively young (20–30 Myr) slabs and intermediate (2–5 cm/yr) subduction rates. We propose that the development of such circular features may explain some of the isolated seismic velocity anomalies in the mantle wedge.

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Tài liệu tham khảo

10.1016/S1631-0713(02)01760-1

10.1080/10407789708914043

10.1029/2002GC000393

10.1016/S0012-821X(01)00482-4

10.1146/annurev.ea.20.050192.002523

10.1111/j.1365-246X.1995.tb06661.x

10.1016/0040-1951(93)90231-8

10.1029/2003GL018213

10.1029/2002GL016600

10.1029/RF003p0105

10.1016/j.epsl.2005.04.033

10.1016/S0012-821X(02)00957-3

10.1046/j.1525-1314.2002.00398.x

10.1007/BF00307329

10.1038/18202

10.1029/1999JB900254

10.1029/2001JB001690

10.1016/S0040-1951(99)00281-4

10.1016/S0012-821X(03)00265-6

10.1016/j.pepi.2003.09.006

10.1016/S0264-3707(99)00025-3

10.1127/0935-1221/2002/0014-0687

10.1016/j.epsl.2004.07.022

10.1130/0-8137-2380-9.117

10.1130/G20018.1

10.1016/j.pepi.2006.02.005

10.1029/2001GC000217

10.1016/0009-2541(86)90053-7

10.1016/0040-1951(84)90013-1

10.2138/am-1996-11-1215

10.1111/j.1525-1314.1998.00140.x

10.1127/ejm/10/3/0395

10.1016/S0012-821X(03)00537-5

10.1029/2002GL015853

10.1029/2000TC900018

Jolivet L., 1999, The Mediterranean Basins: Tertiary Extension Within the Alpine Orogen, 427

10.1029/2000GL011789

10.1130/0091-7613(1998)026<0375:SOOARO>2.3.CO;2

10.1016/S0012-821X(01)00347-8

10.1038/35077056

10.1130/0091-7613(1984)12<221:MCCOCT>2.0.CO;2

10.1016/j.pepi.2004.08.024

10.1016/j.tecto.2003.12.009

10.1016/0016-7037(80)90283-5

10.1016/j.pepi.2004.08.030

10.1016/0377-0273(92)90073-M

10.1016/S0009-2541(97)00150-2

10.1146/annurev.earth.30.091201.140550

10.1029/95JB02506

10.2138/am-1999-1-201

Ranalli G., 1995, Rheology of the Earth

10.1126/science.1063891

Rudolph M. L., 2005, Challenges in the visualization of a mantle dynamics simulation using one billion tracers, Comput. Fluid Solid Mech.

10.1016/j.epsl.2004.04.018

10.1016/S0012-821X(98)00142-3

Schurr B.(2001) Seismic structure of the Central Andean subduction zone from local earthquake data Sci. Tech. Rep. STR01/01 GeoForschungsZentrum Potsdam Potsdam Germany.

10.1016/S0012-821X(03)00441-2

10.1016/0016-7037(89)90189-0

10.1029/2001RG000108

10.1093/petrology/35.3.619

10.1016/S0012-821X(02)00465-X

10.1029/95JB00191

Thompson A. B., 1979, Entropy of mixing in Sanidine, Am. Mineral., 64, 57

10.1029/JB084iB03p01049

10.1016/j.pepi.2004.09.008

10.1016/S0012-821X(00)00240-5

10.1016/j.epsl.2004.04.013

10.1007/s00410-003-0454-1

10.1046/j.1525-1314.2003.00454.x

10.1016/S0264-3707(01)00071-0

10.1016/j.lithos.2004.03.002

10.1126/science.290.5498.1910

10.1130/G20261.2

10.1016/j.pepi.2003.07.032