Can the mantle entrain D00?

[1] A series of laboratory experiments for mixing between the more viscous upper layer and the less viscous lower layer has been performed to study how the less viscous D00 mixes with the overlying more viscous mantle. Experimental results show that the style of entrainment when the more viscous layer overlies the less viscous layer is different from the opposite case. In the latter case the interface between the two layers moves upward, indicating that the more viscous lower layer asymmetrically entrains the less viscous upper layer. However, in the former case, an interfacial layer develops between the two layers and the interface does not move, indicating that the volumetric ratio of the two layers remains unchanged. It has been suggested that the compositional difference between mid-ocean ridge basalts (MORB) and ocean island basalts (OIB) originates from the entrainment of D00 by the mantle plumes. The experimental results suggest that the mantle plume entrains only the interfacial layer, thus modifying the composition of OIB. The volume of D00 would remain unchanged since D00 is formed.

[1]  K. Kurita,et al.  Heat transfer and interfacial temperature of two-layered convection: Implications for the D00-mantle coupling , 2003 .

[2]  M. Manga,et al.  The influence of a chemical boundary layer on the fixity, spacing and lifetime of mantle plumes , 2002, Nature.

[3]  I. Kumagai.  On the anatomy of mantle plumes: effect of the viscosity ratio on entrainment and stirring , 2002 .

[4]  K. Kurita,et al.  Rayleigh-Bénard convection with an inclined upper boundary. , 2002, Physical review. E, Statistical, nonlinear, and soft matter physics.

[5]  L. Wen,et al.  An SH hybrid method and shear velocity structures in the lowermost mantle beneath the central Pacific and South Atlantic Oceans , 2002 .

[6]  E. Ohtani,et al.  Density of basaltic melt at high pressure and stability of the melt at the base of the lower mantle , 2001 .

[7]  B. Hager,et al.  Inversion for mantle viscosity profiles constrained by dynamic topography and the geoid, and their estimated errors , 2000 .

[8]  L. Kellogg,et al.  Numerical models of a dense layer at the base of the mantle and implications for the geodynamics of D , 2000 .

[9]  E. Garnero.  Heterogeneity of the Lowermost Mantle , 2000 .

[10]  R. Boehler.  High‐pressure experiments and the phase diagram of lower mantle and core materials , 2000 .

[11]  A. Davaille,et al.  Simultaneous generation of hotspots and superswells by convection in a heterogeneous planetary mantle , 1999, Nature.

[12]  T. Lay,et al.  Small‐scale lateral shear velocity and anisotropy heterogeneity near the core‐mantle boundary beneath the central Pacific imaged using broadband ScS waves , 1999 .

[13]  A. Davaille.  Two-layer thermal convection in miscible viscous fluids , 1999, Journal of Fluid Mechanics.

[14]  J. Gerald,et al.  Mineralogy and dynamics of a pyrolite lower mantle , 1998, Nature.

[15]  T. Lay,et al.  Seismic anisotropy in the lowermost mantle beneath the Pacific , 1998 .

[16]  Thorne Lay,et al.  The core–mantle boundary layer and deep Earth dynamics , 1998, Nature.

[17]  J. Vidale,et al.  Evidence for partial melt at the core–mantle boundary north of Tonga from the strong scattering of seismic waves , 1998, Nature.

[18]  T. Lay,et al.  A strongly negative shear velocity gradient and lateral variability in the lowermost mantle beneath the Pacific , 1997 .

[19]  E. R. Engdahl,et al.  Evidence for deep mantle circulation from global tomography , 1997, Nature.

[20]  A. Hofmann,et al.  Mantle geochemistry: the message from oceanic volcanism , 1997, Nature.

[21]  C. Farnetani.  mantle plumes: The role of , 1997 .

[22]  E. Garnero,et al.  Seismic Evidence for Partial Melt at the Base of Earth's Mantle , 1996, Science.

[23]  P. Silver,et al.  Constraints from seismic anisotropy on the nature of the lowermost mantle , 1996, Nature.

[24]  Y. Watanabe,et al.  Field occurrence, geochemistry and petrogenesis of the Archean Mid-Oceanic Ridge Basalts (AMORBs) of the Cleaverville area, Pilbara Craton, Western Australia , 1996 .

[25]  N. Arndt,et al.  Constraining the potential temperature of the Archaean mantle: A review of the evidence from komatiites , 1993 .

[26]  D. Stevenson,et al.  SUSPENSION IN CONVECTIVE LAYERS AND STYLE OF DIFFERENTIATION OF A TERRESTRIAL MAGMA OCEAN , 1993 .

[27]  T. Ahrens,et al.  The Equation of State of a Molten Komatiite 2. Application to Komatiite Petrogenesis and the Hadean Mantle , 1991 .

[28]  P. Olson,et al.  Experiments on the interaction of thermal convection and compositional layering at the base of the mantle , 1991 .

[29]  N. Sleep.  Gradual entrainment of a chemical layer at the base of the mantle by overlying convection , 1988 .

[30]  P. Olson.  An experimental approach to thermal convection in a two‐layered mantle , 1984 .

[31]  M. Kurz,et al.  Constraints on evolution of Earth's mantle from rare gas systematics , 1983, Nature.

[32]  F. Richter,et al.  On some consequences and possible causes of layered mantle convection , 1981 .

[33]  Ruby Krishnamurti,et al.  Some further studies on the transition to turbulent convection , 1973, Journal of Fluid Mechanics.

[34]  R. Kraichnan.  Turbulent Thermal Convection at Arbitrary Prandtl Number , 1962 .