The core-mantle boundary layer and deep Earth dynamics

Nature

Volumn 392, Issue 6675, 1998, Pages 461-468

  Lay, Thorne ^a   Williams, Quentin ^a   Garnero, Edward J ^b  

^a UNIVERSITY OF CALIFORNIA   (United States)

^b UNIVERSITY OF CALIFORNIA   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

CORE-MANTLE BOUNDARY; GEODYNAMICS; SEISMOLOGY;

ANISOTROPY; CHEMICAL REACTION; EARTHQUAKE; GEOLOGY; MAGNETIC FIELD; PHYSICS; PRIORITY JOURNAL; REVIEW; THERMODYNAMICS; VELOCITY;

EID: 0032473957     PISSN: 00280836     EISSN: None     Source Type: Journal    
DOI: 10.1038/33083     Document Type: Review

References (94)

1. Lay, T. Structure of the core-mantle transition zone: A chemical and thermal boundary layer. Eos 70, 54-55, 58-59 (1989).
2. Loper, D. E. & Lay, T. The core-mantle boundary region. J. Geophys. Res. 100, 6397-6420 (1995).
3. Williams, Q. & Jeanloz, R. Melting relations in the iron-sulfur system at high pressures: Implications for the thermal state of the Earth. J. Geophys. Res. 95, 19299-19310 (1990).
4. Boehler, R. Temperatures in the Earth's core from melting-point measurements of iron at high static pressures. Nature 363, 534-536 (1993).
5. Davies, G. F. Ocean bathymetry and mantle convection, 1, Large-scale flow and hotspots. J. Geophys. Res. 93, 10447-10480 (1988).
6. Sleep, N. H. Hotspots and mantle plumes: Some phenomenology. J. Geophys. Res. 95, 6715-6736 (1990).
7. Loper, D. E. Mantle plumes. Tectonophysics 187, 373-384 (1991).
8. Hoffman, A. W. & White, W. M. Mantle plumes from ancient oceanic crust. Earth Planet. Sci. Lett. 57, 421-436 (1982).
9. Woodhead, J. D., Greenwood, P., Harmon, R. S. & Stoffers, P. Oxygen isotope evidence for recycled crust in the source of EM-type ocean island basalts. Nature 362, 809-813 (1993).
10. Su, W-J., Woodward, R. & Dziewonski, A. M. Degree 12 model of shear velocity heterogeneity in the mantle. J. Geophys. Res. 99, 6945-6980 (1994).
11. Li, X. D. & Romanowicz, B. Global mantle shear velocity model developed using nonlinear asymptotic coupling theory. J. Geophys. Res. 101, 22245-22272 (1996).
12. Masters, T. G., Johnson, S., Laske, G. & Bolton, H. A shear-velocity model of the mantle. Phil. Trans. R. Soc. Lond. A 354, 1385-1411 (1996).
13. Gubbins, D. Core-mantle interactions. Tectonophysics 187, 385-391 (1991).
14. Bloxham, J. & Jackson, A. Fluid flow near the surface of Earth's outer core. Rev. Geophys. 29, 97-120 (1991).
15. Hide, R., Speith, M. A., Clayton, R. W., Hager, B. H. & Voorhies, C. V. in Relating Geophysical Structures and Processes: The Jeffreys Volume (eds Aki, K. & Dmowska, R.) 107-120 (Geophys. Monogr. Ser. 76, Am. Geophys Union, Washington DC, 1993).
16. Knittle, E. & Jeanloz, R. Earth's core-mantle boundary: Results of experiments at high pressures and temperatures. Science 251, 1438-1443 (1991).
17. Poirier, J.-P. Core-infiltrated mantle and the nature of the D″ layer. J. Geomagn. Geoelectr. 45, 1221-1227 (1993).
18. Lay, T. Seismology of the lower mantle and core-mantle boundary. Rev. Geophys. Suppl. 325-328 (1995).
19. Weber, M. et al. in Seismic Modeling of the Earth's Structure (eds Boschi, E., Ekström, G. & Morelli, A.) 399-442 (Istit. Naz. di Geophys., Rome, 1996).
20. Ding, X. & Helmberger, D. V. Modeling D″ structure beneath Central America with broadband seismic data. Phys. Earth Planet Inter. 101, 245-270 (1997).
21. Wysession, M. E. et al. The D″ discontinuity and its implications. in The Core-Mantle Boundary (eds Gurnis, M., Buffett, B. A., Knittle, E. & Wysession, M.) (Am. Geophys. Union, in the press).
22. Vinnik, L., Romanowicz, B., Le Stunff, Y. & Makeyeva, L. Seismic anisotropy in the D″ layer. Geophys. Res. Lett. 22, 1657-1660 (1995).
23. Kendall, J.-M. & Silver, P. G. Constraints from seismic anisotropy on the nature of the lowermost mantle. Nature 381, 409-412 (1996).
24. Matzel, E., Sen, M. K. & Grand, S. P. Evidence for anisotropy in the deep mantle beneath Alaska. Geophys. Res. Lett. 23, 2417-2420 (1996).
25. Garnero, E. J. & Lay, T. Lateral variations in lowermost mantle shear wave anisotropy beneath the north Pacific and Alaska. J. Geophys. Res. 102, 8121-8135 (1997).
26. Lay, T., Garnero, E. J., Williams, Q., Kellogg, L. & Wysession, M. E. Seismic wave anisotropy in the D″ region and its implications. in The Core-Mantle Boundary (eds Gurnis, M., Buffett, B. A., Knittle, E. & Wysession, M.) (Am. Geophys. Union, in the press).
27. Garnero, E. J. & Helmberger, D. V. A very slow basal layer underlying large-scale low-velocity anomalies in the lower mantle beneath the Pacific: evidence from core phases. Phys. Earth Planet. Inter. 91, 161-176 (1995).
28. Mori, J. & Helmberger, D. V. Localized boundary layer below the mid-Pacific velocity anomaly identified from a PcP precursor. J. Geophys. Res. 100, 20359-20365 (1995).
29. Garnero, E. J., Revenaugh, J., Williams, Q., Lay, T. & Kellogg, L. Ultra-low velocity zone at the core-mantle boundary. in The Core-Mantle Boundary (eds Gurnis, M., Buffett, B. A., Knittle, E. & Wysession, M.) (Am Geophys. Union, in the press).
30. Grand, S. P., van der Hilst, R. D. & Widiyantoro, S. Global seismic tomography: A snapshot of convection in the Earth. GSA Today 7, 1-7 (1997).
31. van der Hilst, R. D., Widiyantoro, S. & Engdahl, E. R. Evidence for deep mantle circulation from global tomography. Nature 386, 578-584 (1997).
32. Young, C. J. & Lay, T. The core mantle boundary. Annu. Rev. Earth Planet. Sci. 15, 25-46 (1987).
33. Wysession, M. E. Large scale structure at the core-mantle boundary from core-diffracted waves. Nature 382, 244-248 (1996).
34. Lay, T. & Helmberger, D. V. A lower mantle S-wave triplication and the shear velocity structure of D″. Geophys. J. R. Astron. Soc. 75, 799-838 (1983).
35. Williams, Q. & Garnero, E. J. Seismic evidence for partial melt at the base of Earth's mantle. Science 273, 1528-1530 (1996).
36. Revenaugh, J. S. & Meyer, R. Seismic evidence of partial melt within a possibly ubiquitous low velocity layer at the base of the mantle. Science 277, 670-673 (1997).
37. Garnero, E. J. & Helmberger, D. V. Seismic detection of a thin laterally varying boundary layer at the base of the mantle beneath the central-Pacific. Geophys. Res. Lett. 23, 977-980 (1996).
38. Bataille, K., Wu, R. S. & Flatté, S. M. Inhomogeneities near the core-mantle boundary evidenced from scattered waves: A review. Pure Appl. Geophys. 132, 151-174 (1990).
39. Vidale, J. E. & Hedlin, M. A. H. Evidence for partial melt at the core-mantle boundary north of Tonga from the strong scattering of seismic waves. Nature 391, 682-685 (1998).
40. Kaneshima, S. & Silver, P. G. A search for source-side anisotropy. Geophys. Res. Lett. 19, 1049-1052 (1992).
41. Meade, C., Silver, P. G. & Kaneshima, S. Laboratory and seismological observations of lower mantle isotropy. Geophys. Res. Lett. 22, 1293-1296 (1995).
42. Pulliam, J. & Sen, M. K. Seismic anisotropy in the core-mantle transition zone. Geophys. J. Int. (in the press).
43. Kendall, J.-M. & Silver, P. G. Investigating causes of D″ anisotropy. in The Core-Mantle Boundary (eds Gumis, M., Buffett, B. A., Knittle, E. & Wysession, M.) (Am Geophys. Union, in the press).
44. Ritsema, J., Lay, T., Garnero, E. J. & Benz, H. Seismic anisotropy in the lowermost mantle beneath the Pacific. Geophys. Res. Lett. (in the press).
45. Weber, M. P and S wave reflections from anomalies in the lowermost mantle. Geophys. J. Int. 115, 183-210 (1993).
46. Lay, T., Garnero, E. J., Young, C. J. & Gaherty, J. B. Scale-lengths of shear velocity heterogeneity at the base of the mantle from S wave differential travel times. J. Geophys. Res. 102, 9887-9910 (1997).
47. Lay, T. & Young, C. J. Analysis of seismic SV waves in the core's penumbra. Geophys. Res. Lett. 18, 1373-1376 (1991).
48. Kendall, J.-M. & Nangini, C. Lateral variations in D″ below the Caribbean. Geophys. Res. Lett. 23, 399-402 (1996).
49. Ritsema, J., Garnero, E. & Lay, T. A strongly negative shear velocity gradient and lateral variability in the lowermost mantle beneath the Pacific. J. Geophys. Res. 102, 20395-20411 (1997).
50. Stacey, F. D. & Loper, D. E. The thermal boundary layer interpretation of D″ and its role as a plume source. Phys. Earth Planet. Inter. 33, 45-55 (1983).
51. Backus, G. E. Long-wave elastic anisotropy produced by horizontal layering. J. Geophys. Res. 67, 4427-4440 (1962).
52. Whitehead, J. A. & Luther, D. S. Dynamics of laboratory diapir and plume models. J. Geophys. Res. 80, 705-717 (1975).
53. Duncan, R. A. & Richards, M. A. Hotspots, mantle plumes, flood basalts, and true polar wander. Rev. Geophys. 29, 31-50 (1991).
54. Ribe, N. M. & de Valpine, D. P. The global hotspot distribution and instability of D″. Geophys. Res. Lett. 21, 1507-1510 (1994).
55. Bercovici, D. & Kelly, A. The non-linear initiation of diapirs and plume heads. Phys. Earth Planet Inter. 101, 119-130 (1997).
56. Karato, S. & Li, P. Diffusion creep in perovskite: Implications for the rheology of the lower mantle. Science 255, 1238-1240 (1992).
57. Williams, Q., Revenaugh, J. & Ganero, E. J. A correlation between ultralow basal velocities in the mantle and hotspots. Science (submitted).
58. Watson, S. & McKenzie, D. P. Melt generation by plumes: A study of Hawaiian volcanism. J. Petrol. 12, 501-537 (1991).
59. Nataf, H.-C. & vanDecar, J. Seismological detection of a mantle plume? Nature 264, 115-120 (1993).
60. Farnetani, C. G. & Richards, M. A. Thermal entrainment and melting in mantle plumes. Earth Planet. Sci. Lett. 136, 251-267 (1995).
61. Leitch, A. M., Steinbach, V. & Yuen, D. A. Centerline temperature of mantle plumes in various geometries: Incompressible flow. J. Geophys. Res. 101, 21928-21846 (1996).
62. Farnetani, C. G. Excess temperature of mantle plumes: The role of chemical stratification across D″. Geophys. Res. Lett. 24, 1583-1586 (1997).
63. Walker, R. J., Morgan, J. W. & Horan, M. F. Osmium-187 enrichment in some plumes - evidence for core-mantle interaction. Science 269, 819-822 (1995).
64. Storey, B. C. The role of mantle plumes in continental breakup - case histories from Gondwanaland. Nature 377, 301-308 (1995).
65. Sleep, N. H., Richards, M. A. & Hager, B. H. On the onset of mantle plumes in the presence of preexisting convection. J. Geophys. Res. 93, 7672-7689 (1988).
66. Davies, G. F. & Gurnis, M. Interaction of mantle dregs with convection: lateral heterogeneity at the core-mantle boundary. Geophys. Res. Lett. 13, 1517-1520 (1986).
67. Sleep, N. H. Gradual entrainment of a chemical layer at the base of the mantle by overlying convection. Geophys. J. 95, 437-447 (1988).
68. Goarant, F., Guyot, F., Peyronneau, J. & Poirier, J. P. High pressure and high-temperature reactions between silicates and liquid iron alloys, in the diamond anvil cell, studied by analytical electron microscopy. J. Geophys. Res. 97, 4477-4487 (1992).
69. Song, Y. & Ahrens, T. J. Pressure-temperature range of reactions between liquid iron in the outer core and mantle silicates. Geophys. Res. Lett. 21, 153-156 (1994).
70. Ito, E., Morooka, K., Ujike, O. & Katsura, T. Reactions between molten iron and silicate melts at high pressure: Implications for the chemical evolution of Earth's core. J. Geophys. Res. 100, 5901-5910 (1995).
71. Manga, M. & Jeanloz, R. Implications of a metal-bearing chemical boundary layer in D″ for mantle dynamics. Geophys. Res. Lett. 23, 3091-3094 (1996).
72. Rigden, S. M., Ahrens, T. J. & Stolper, E. M. High-pressure equation of state of molten anorthite and diopside. J. Geophys. Res. 94, 9508-9522 (1989).
73. McFarlane, E., Drake, M. J. & Rubie, D. C. Element partitioning between Mg-perovskite, magnesiowüstite and silicate melt at conditions of the Earth's mantle. Geochim. Cosmochim. Acta 58, 5161-5172 (1994).
74. Ohtani, E., Kato, T. & Ito, E. Transition metal partitioning between lower mantle and core materials. Geophys. Res. Lett. 18, 85-88 (1991).
75. Duffy, T. & Ahrens, T. J. in High-Pressure Research: Application to Earth and Planetary Sciences (eds Syono, Y. & Manghnani, M. H.) 197-205 (Terra Scientific, Tokyo, 1992).
76. Knittle, E. The solid/liquid partitioning of major and radiogenic elements at lower mantle pressures: Implications for the core-mantle boundary region. in The Core-Mantle Boundary (eds Gurnis, M., Buffett, B. A., Knittle, E. & Wysession, M.) (Am Geophys. Union, in the press).
77. 4 at the core-mantle boundary of the Earth. Science 275, 1623-1625 (1997).
78. Crough, S. T. & Jurdy, D. M. Subducted lithosphere, hot spots and the geoid. Earth Planet. Sci. Lett. 48, 15-22 (1980).
79. Karato, S. I., Zhang, S. & Wenk, H. R. Superplasticity in Earth's lower mantle: Evidence from seismic anisotropy and rock physics. Science 270, 458-461 (1995).
80. Frost, H. J. & Ashby, M. F. Deformation Mechanism Maps (Pergamon, Oxford, 1982).
81. Cohen, R. E. in High-Pressure Research: Application to Earth and Planetary Sciences (eds Syono, Y. & Manghnani, M. H.) 425-431 (Terra Scientific, Tokyo, 1992).
82. Stewart, D. N., Buse, F. H., Walker, K. A. & Gubbins, D. Geomagnetism, Earth rotation and the electrical conductivity of the lower mantle. Phys. Earth Planet. Inter. 92, 199-214 (1995).
83. Larson, R. L. & Olson, P. Mantle plumes control magnetic reversal frequency. Earth Planet Sci. Lett. 107, 437-447 (1991).
84. Marzocchi, W. & Mulargia, F. The periodicity of geomagnetic reversals. Phys. Earth Planet. Inter. 73, 222-228 (1992).
85. Laj, C., Mazaud, A., Weeks, R., Fuller, M. & Herrero-Berverra, E. Geomagnetic reversal paths. Nature 351, 447-450 (1991).
86. Valet, J. P., Tucholka, P., Courtillot, V. & Meynadier, L. Palaeomagnetic constraints on the geometry of the geomagnetic field during reversals. Nature 356, 400-407 (1992).
87. Hoffman, K. Dipolar reversal states of the geomagnetic field and core-mantle dynamics. Nature 359, 789-794 (1992).
88. Aurnou, J. M., Buttles, J. L., Neumann, G. A. & Olson, P. L. Electromagnetic core-mantle coupling and paleomagnetic reversal paths. Geophys. Res. Lett. 23, 2705-2708 (1996).
89. Courtillot, V. & Valet, J. P. Secular variation of the Earth's magnetic field: From jerks to reversals. C. R. Acad. Sci. 320, 903-922 (1995).
90. Shankland, T. J., Peyronneau, J. & Poirier, J. P. Electrical conductivity of the Earth's lower mantle. Nature 366, 453-455 (1993).
91. Li, X. & Jeanloz, R. Laboratory studies of the electrical conductivity of silicate perovskites at high pressures and temperatures. J. Geophys. Res. 95, 5067-5078 (1990).
92. Tonks, W. B. & Melosh, H. J. in Origin of the Earth (eds Newsom, H. E. & Jones, J. H.) 151-174 (Oxford Univ. Press, New York, 1990).
93. Birch, F. Elasticity and constitution of the Earth's interior. J. Geophys. Res. 57, 227-286 (1952).
94. Lithgow-Bertelloni, C. & Richards, M. A. The dynamics of Cenozoic and Mesozoic plate motions. Annu. Rev. Earth Planet. Sci. (in the press).