Petrology, elasticity, and composition of the mantle transition zone

We compare the predictions of compositional models of the mantle transition zone to observed seismic properties by constructing phase diagrams in the MgO-FeO-CaO-Al2O3-SiO2 system and estimating the elasticity of the relevant minerals. Mie-Gruneisen and Birch-Murnaghan finite strain theory are combined with ideal solution theory to extrapolate experimental measurements of thermal and elastic properties to high pressures and temperatures. The resulting thermodynamic potentials are combined with the estimated phase diagrams to predict the density, seismic parameter, and mantle adiabats for a given compositional model. We find that the properties of pyrolite agree well with the observed density and bulk sound velocity of the upper mantle and transition zone. Piclogite significantly underestimates the magnitude of the 400-km velocity discontinuity and overestimates the velocity gradient in the transition zone. Substantially enriching piclogite in Al provides an acceptable fit to the observations. Invoking a chemical boundary layer between the uppermost mantle and transition zone leads to poor agreement with observed seismic properties for the compositions considered. Within the transition zone, the dissolution of garnet to Ca-perovskite near 18 GPa may explain the proposed 520-km seismic discontinuity. Below 700 km depth, all compositions disagree with observed bulk sound velocities, implying that the lower mantle is chemically distinct from the upper mantle.

[1]  H. Mao,et al.  Simultaneous high-P, high-T X ray diffraction study of β-(Mg,Fe)2SiO4 to 26 GPa and 900 K , 1992 .

[2]  J. Gerald,et al.  Spinel elasticity and seismic structure of the transition zone of the mantle , 1991, Nature.

[3]  Jean-Paul Montagner,et al.  Global upper mantle tomography of seismic velocities and anisotropies , 1991 .

[4]  G. Bock,et al.  A global study of S-to-P and P-to-S conversions from the upper mantle transition zone , 1991 .

[5]  H. Mao,et al.  Effect of pressure, temperature, and composition on lattice parameters and density of (Fe,Mg)SiO3‐perovskites to 30 GPa , 1991 .

[6]  V. Sautter,et al.  Ultradeep (>300 Kilometers) Ultramafic Xenoliths: Petrological Evidence from the Transition Zone , 1991, Science.

[7]  B. Kennett,et al.  Traveltimes for global earthquake location and phase identification , 1991 .

[8]  H. Mao,et al.  Experimental determination of element partitioning and calculation of phase relations in the MgO‐FeO‐SiO2 system at high pressure and high temperature , 1991 .

[9]  R. Jeanloz,et al.  Structural and electronic properties of Fe2SiO4-fayalite at ultrahigh pressures: Amorphization and gap closure , 1990 .

[10]  A. Revcolevschi,et al.  Elasticity, shear‐mode softening and high‐pressure polymorphism of wüstite (Fe1‐xO) , 1990 .

[11]  D. Weidner,et al.  Elastic properties of the pyrope‐majorite solid solution series , 1990 .

[12]  R. Hazen,et al.  Effects of Fe/Mg on the compressibility of synthetic wadsleyite: β-(Mg1-xFex)2SiO4 (x≤0.25) , 1990 .

[13]  L. Stixrude,et al.  Fundamental thermodynamic relations and silicate melting with implications for the constitution of D , 1990 .

[14]  R. Liebermann,et al.  Pressure Dependence of Elastic Wave Velocity for β-Mg2SiO4 and the Composition of the Earth's Mantle , 1990, Science.

[15]  J. Bass,et al.  Elasticity of a majorite‐pyrope solid solution , 1990 .

[16]  T. Gasparik.  Phase relations in the transition zone , 1990 .

[17]  R. Jeanloz,et al.  Experimental petrology of the lower mantle: A natural peredottte taken to 54 GPA , 1990 .

[18]  B. Wood.  Postspinel transformations and the width of the 670‐km Discontinuity: A comment on “postspinel transformations in the system Mg2SiO4–Fe2SiO4 and some geophysical implications” by E. Ito and E. Takahashi , 1990 .

[19]  G. Wolf,et al.  Thermodynamically consistent decompression: Implications for lower mantle composition , 1990 .

[20]  P. Silver,et al.  Constraints on lower mantle composition and temperature from density and bulk sound velocity profiles , 1990 .

[21]  R. Clayton,et al.  P and S wave travel time inversions for subducting slab under the island arcs of the northwest Pacific , 1990 .

[22]  B. Kennett,et al.  An investigation of the upper mantle beneath NW Australia using a hybrid seismograph array , 1990 .

[23]  J. Leger,et al.  Compressions of synthetic pyrope, spessartine and uvarovite garnets up to 25 GPa , 1990 .

[24]  Peter M. Shearer,et al.  Seismic imaging of upper-mantle structure with new evidence for a 520-km discontinuity , 1990, Nature.

[25]  B. Dost.  Upper Mantle Structure Under Western Europe from Fundamental and Higher Mode Surface Waves Using the Nars Array , 1990 .

[26]  H. Melosh,et al.  The physics of crystal settling and suspension in a turbulent magma ocean. , 1990 .

[27]  D. Helmberger,et al.  Upper mantle P velocity structure of the Canadian Shield , 1989 .

[28]  H. Mao,et al.  Stability and equation of state of CaSiO3‐Perovskite to 134 GPa , 1989 .

[29]  J. Bass,et al.  Elasticity of a grossular-pyrope-almandine garnet , 1989 .

[30]  D. L. Anderson,et al.  Constrained reference mantle model , 1989 .

[31]  C. Agee,et al.  Partitioning “equilibrium”, temperature gradients, and constraints on Earth differentiation , 1989 .

[32]  Alexandra Navrotsky,et al.  Olivine-modified spinel-spinel transitions in the system Mg2SiO4-Fe2SiO4: Calorimetric measurements, thermochemical calculation, and geophysical application , 1989 .

[33]  T. Katsura,et al.  The system Mg2SiO4‐Fe2SiO4 at high pressures and temperatures: Precise determination of stabilities of olivine, modified spinel, and spinel , 1989 .

[34]  M. Manghnani,et al.  A study of phase transformation in hedenbergite to 40 GPa at ∼1200° C , 1989 .

[35]  E. Ito,et al.  Postspinel transformations in the system Mg2SiO4‐Fe2SiO4 and some geophysical implications , 1989 .

[36]  D. Yuen,et al.  Penetrative convective flows induced by internal heating and mantle compressibility , 1989 .

[37]  J. H. Stout,et al.  A five-parameter temperature-corrected Murnaghan equation for P-V-T surfaces , 1989 .

[38]  R. Jeanloz,et al.  Density and composition of the lower mantle , 1989, Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences.

[39]  B. Hager,et al.  Long-wavelength variations in Earth’s geoid: physical models and dynamical implications , 1989, Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences.

[40]  J. Bass.  Elasticity of grossular and spessartite garnets by Brillouin spectroscopy , 1989 .

[41]  O. Anderson,et al.  Elasticity of single‐crystal forsterite measured to 1700 K , 1989 .

[42]  R. Jeanloz.  Shock wave equation of state and finite strain theory , 1989 .

[43]  T. Yagi,et al.  High-pressure and high-temperature phase relations in CaSiO3 and CaMgSi2O6 and elasticity of perovskite-type CaSiO3 , 1989 .

[44]  H. Mao,et al.  Bulk moduli of magnesiowüstites from static compression measurements , 1989 .

[45]  D. L. Anderson,et al.  Seismic velocities in mantle minerals and the mineralogy of the upper mantle , 1989 .

[46]  J. Susaki,et al.  Phase transformations in diopside CaMgSi2O6 at pressures Up to 25 GPa , 1989 .

[47]  E. Ohtani.  Chemical stratification of the mantle formed by melting in the early stage of the terrestrial evolution , 1988 .

[48]  H. Takei,et al.  The pressure and temperature dependence of the elastic properties of single-crystal fayalite Fe2SiO4 , 1988 .

[49]  M. Grad.  Seismic model of the Earth's crust and upper mantle for the east European platform , 1988 .

[50]  A. E. Ringwood,et al.  Experimental determination of element partitioning between silicate perovskites, garnets and liquids: constraints on early differentiation of the mantle , 1988 .

[51]  M. Korn.  P-wave coda analysis of short-period array data and the scattering and absorptive properties of the lithosphere , 1988 .

[52]  R. Graves,et al.  Upper mantle cross section from Tonga to Newfoundland , 1988 .

[53]  D. Weidner,et al.  Elastic properties of hedenbergite , 1988 .

[54]  P. Silver,et al.  Deep Slabs, Geochemical Heterogeneity, and the Large-Scale Structure of Mantle Convection: Investigation of an Enduring Paradox , 1988 .

[55]  Arthur L. Lerner-Lam,et al.  How Thick Are the Continents , 1987 .

[56]  A. E. Ringwood,et al.  Phase transformations in a harzburgite composition to 26 GPa: implications for dynamical behaviour of the subducting slab , 1987 .

[57]  M. Kanzaki.  Ultrahigh-pressure phase relations in the system Mg4Si4O12Mg3Al2Si3O12 , 1987 .

[58]  H. Paulssen.  Lateral heterogeneity of Europe's upper mantle as inferred from modelling of broad-band body waves , 1987 .

[59]  E. Ito,et al.  Melting of peridotite at uppermost lower-mantle conditions , 1987, Nature.

[60]  B. Wood,et al.  Olivine‐spinel transitions: Experimental and thermodynamic constraints and implications for the nature of the 400‐km seismic discontinuity , 1987 .

[61]  T. Irifune.  An experimental investigation of the pyroxene-garnet transformation in a pyrolite composition and its bearing on the constitution of the mantle , 1987 .

[62]  R. Jeanloz,et al.  Synthesis and Equation of State of (Mg,Fe) SiO3 Perovskite to Over 100 Gigapascals , 1987, Science.

[63]  P. Silver,et al.  Observations of body wave multipathing from broadband seismograms: Evidence for lower mantle slab penetration beneath the Sea of Okhotsk , 1986 .

[64]  J. Watt,et al.  Walpole bounds on the effective elastic moduli of isotropic multicomponent composites , 1986 .

[65]  H. Lyon‐Caen.  Comparison of the upper mantle shear wave velocity structure of the Indian Shield and the Tibetan Plateau and tectonic implications , 1986 .

[66]  Thomas J. Ahrens,et al.  Shock wave equation of state of enstatite , 1986 .

[67]  M. Gurnis,et al.  Mixing in numerical models of mantle convection incorporating plate kinematics , 1986 .

[68]  R. Jarrard.  Relations among subduction parameters , 1986 .

[69]  D. L. Anderson,et al.  Transition region of the Earth's upper mantle , 1986, Nature.

[70]  T. Jordan,et al.  Slab penetration into the lower mantle beneath the Mariana and other island arcs of the northwest Pacific , 1986 .

[71]  Tetsuo Irifune,et al.  The eclogite-garnetite transformation at high pressure and some geophysical implications , 1986 .

[72]  Raymond Jeanloz,et al.  Temperature distribution in the crust and mantle , 1986 .

[73]  Raymond Jeanloz,et al.  Thermal expansion of silicate perovskite and stratification of the Earth's mantle , 1986, Nature.

[74]  D. Weidner,et al.  A mineral physics test of a pyrolite mantle , 1985 .

[75]  M. Walck.  The upper mantle beneath the north-east Pacific rim - A comparison with the Gulf of California , 1985 .

[76]  D. Turcotte.  Geodynamic mixing in the mesosphere boundary layer and the origin of oceanic islands: Geophysical Re , 1985 .

[77]  R. A. Robie,et al.  High-temperature heat capacities and derived thermodynamic properties of anthophyllite, diopside, dolomite, enstatite, bronzite, talc, tremolite and wollastonite , 1985 .

[78]  J. Leven.  The application of synthetic seismograms to the interpretation of the upper mantle P-wave velocity structure in northern Australia , 1985 .

[79]  D. Helmberger,et al.  Upper mantle shear structure beneath the northwest Atlantic Ocean , 1984 .

[80]  Satoshi Sasaki,et al.  Single‐crystal elastic properties of the spinel phase of Mg2SiO4 , 1984 .

[81]  G. Davies.  Geophysical and isotopic constraints on mantle convection: An interim synthesis , 1984 .

[82]  Don L. Anderson,et al.  Mineralogy and composition of the upper mantle , 1984 .

[83]  Jay D. Bass,et al.  Elasticity of single‐crystal orthoferrosilite , 1984 .

[84]  D. Weidner,et al.  Single-Crystal Elastic Properties of the Modified Spinel (Beta) Phase of Magnesium Orthosilicate , 1984, Science.

[85]  T. Jordan,et al.  Slab penetration into the lower mantle , 1984 .

[86]  M. Walck.  The P-wave upper mantle structure beneath an active spreading centre: the Gulf of California , 1984 .

[87]  D. Helmberger,et al.  Upper mantle shear structure of North America , 1984 .

[88]  Bradford H. Hager,et al.  The distribution of earthquakes with depth and stress in subducting slabs , 1984 .

[89]  D. Giardini,et al.  Deep seismicity and modes of deformation in Tonga subduction zone , 1984, Nature.

[90]  Ian Jackson,et al.  Some geophysical constraints on the chemical composition of the earth's lower mantle , 2013 .

[91]  D. DePaolo.  Geochemical evolution of the crust and mantle , 1983 .

[92]  Raymond Jeanloz,et al.  Phase transitions and mantle discontinuities , 1983 .

[93]  Isao Suzuki,et al.  ELASTICITY AND THERMAL EXPANSION OF A NATURAL GARNET UP TO 1, 000K , 1983 .

[94]  M. Nakada,et al.  Upper mantle structure beneath the Canadian Shield derived from higher modes of surface waves. , 1983 .

[95]  Y. Fukao,et al.  Shear Velocity in the Mantle Transition Zone , 1982 .

[96]  Ian Jackson,et al.  The Elasticity of Periclase to 3 GPa and Some Geophysical Implications , 1982 .

[97]  Hiroshi Watanabe,et al.  Thermochemical Properties of Synthetic High-Pressure Compounds Relevant to the Earth’s Mantle , 1982 .

[98]  G. McMechan.  Mantle P-wave velocity structure beneath Antarctica , 1981 .

[99]  L. Burdick.  A comparison of the upper mantle structure beneath North America and Europe , 1981 .

[100]  Raymond Jeanloz,et al.  Majorite: Vibrational and compressional properties of a high‐pressure phase , 1981 .

[101]  D. L. Anderson,et al.  Preliminary reference earth model , 1981 .

[102]  Stephen J. Finch,et al.  Elastic properties from acoustic and volume compression experiments , 1981 .

[103]  L. Vinnik,et al.  Deep structure of the East European platform according to seismic data , 1981 .

[104]  O. J. Kleppa,et al.  Thermochemistry of forsterite-fayalite olivine solutions , 1981 .

[105]  C. Prewitt,et al.  High-pressure structural study of diopside , 1981 .

[106]  H. Takei,et al.  Thermal expansion of fayalite, Fe2SiO4 , 1981 .

[107]  J. Given,et al.  Upper mantle structure of northwestern Eurasia , 1980 .

[108]  R. C. Newton,et al.  Thermodynamics of pyrope‐grossular garnets and their stabilities at high temperatures and high pressures , 1980 .

[109]  R. Hardy,et al.  Temperature and pressure dependence of intrinsic anharmonic and quantum corrections to the equation of state , 1980 .

[110]  I. Suzuki,et al.  THERMAL EXPANSION OF MODIFIED SPINEL, β-Mg2SiO4 , 1980 .

[111]  A. L. Hales,et al.  A compressional velocity distribution for the upper mantle , 1980 .

[112]  G. McMechan.  An amplitude constrained P-wave velocity profile for the upper mantle beneath the Eastern United States , 1979, Bulletin of the Seismological Society of America.

[113]  Raymond Jeanloz,et al.  Convection, composition, and the thermal state of the lower mantle , 1979 .

[114]  R. Uhrhammer.  Shear-wave velocity structure for a spherically averaged earth , 1979 .

[115]  S. Akimoto,et al.  High-pressure phase equilibria in a garnet lherzolite, with special reference to Mg2+Fe2+ partitioning among constituent minerals , 1979 .

[116]  D. Weidner,et al.  Elasticity of diopside , 1979 .

[117]  R. A. Robie,et al.  High-temperature heat capacities of corundum, periclase, anorthite, CaAl 2 Si 2 O 8 glass, muscovite, pyrophyllite, KAlSi 3 O 8 glass, grossular, and NaAlSi 3 O 8 glass , 1979 .

[118]  Mineo Kumazawa,et al.  Thermal expansion of .GAMMA.-Mg2SiO4. , 1979 .

[119]  Jun Ito,et al.  Elasticity of orthoenstatite , 1978 .

[120]  B. Julian,et al.  Radial variation of compressional and shear velocities in the Earth's lower mantle , 1978 .

[121]  D. Helmberger,et al.  The upper mantle P velocity structure of the western United States , 1978 .

[122]  S. Akimoto,et al.  Pyroxene-garnet solid-solution equilibria in the systems Mg4Si4O12Mg3Al2Si3O12 and Fe4Si4O12Fe3Al2Si3O12 at high pressures and temperatures , 1977 .

[123]  Y. Fukao.  Upper mantle P structure on the ocean side of the Japan‐Kurile Arc , 1977 .

[124]  Y. S. Touloukian.  Thermal Expansion: Nonmetallic Solids , 1977 .

[125]  B. Olinger,et al.  COMPRESSION STUDIES OF FORSTERITE (Mg2SiO4) AND ENSTATITE(MgSiO3) , 1977 .

[126]  J. Watt,et al.  The Elastic Properties of Composite Materials , 1976 .

[127]  R. S. Hart,et al.  Shear velocity and density of an attenuating earth , 1976 .

[128]  G. Calcagnile,et al.  P-Wave Velocities in the Upper Mantle Beneath Fennoscandia and Western Russia , 1976 .

[129]  R. Wiggins,et al.  Upper mantle structure in western Canada , 1976 .

[130]  Taro Takahashi,et al.  Isothermal compression of grossular garnets to 250 Kbar and the effect of calcium on the bulk modulus , 1976 .

[131]  L. Finger,et al.  The thermal expansion of diopside to 800 degrees C and a refinement of the crystal structure at 700 degrees C , 1976 .

[132]  C. Prewitt,et al.  Orthoferrosilite : High-temperature crystal chemistry , 2022 .

[133]  R. S. Hart.  Shear velocity in the lower mantle from explosion data , 1975 .

[134]  L. Finger,et al.  The Effect of Ca-Fe Substitution on the Clinopyroxene Crystal Structure , 1975 .

[135]  I. Suzuki.  Thermal Expansion of Periclase and Olivine, and their Anharmonic Properties , 1975 .

[136]  F. Gilbert,et al.  An application of normal mode theory to the retrieval of structural parameters and source mechanisms from seismic spectra , 1975, Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences.

[137]  R. Kind,et al.  Computations of SV waves in realistic Earth models , 1975 .

[138]  A. Ringwood.  Composition and petrology of the earth's mantle , 1975 .

[139]  I. Suzuki.  Cell Parameters and Linear Thermal Expansion Coefficients of Orthopyroxenes , 1975 .

[140]  T. Jordan,et al.  Earth structure from free oscillations and travel times: Geophys , 1974 .

[141]  J. Papike,et al.  High-temperature crystal chemistry of acmite, diopside, hedenbergite, jadeite, spodumene, and ureyite , 1973 .

[142]  Chi‐yuen Wang,et al.  A Simple Earth Model , 1972 .

[143]  K. Abe,et al.  An Earth model consistent with free oscillation and surface wave data , 1972 .

[144]  J. Cleary,et al.  P wave travel-time gradient measurements for the warramunga seismic array and lower mantle structure , 1972 .

[145]  G. Buchbinder.  A velocity structure of the Earth's core , 1971, Bulletin of the Seismological Society of America.

[146]  M. Randall.  A Revised Travel-Time Table for S , 1971 .

[147]  P. Molnar,et al.  Distribution of stresses in the descending lithosphere from a global survey of focal‐mechanism solutions of mantle earthquakes , 1971 .

[148]  J. N. Fritz,et al.  CHAPTER VII – THE EQUATION OF STATE OF SOLIDS FROM SHOCK WAVE STUDIES , 1970 .

[149]  G. R. Barsch,et al.  Elastic constants of single‐crystal forsterite as a function of temperature and pressure , 1969 .

[150]  J. Derr.  Internal structure of the Earth inferred from free oscillations , 1969 .

[151]  J. W. Fairborn.  Shear wave velocities in the lower mantle , 1969 .

[152]  P. R. Bevington,et al.  Data Reduction and Error Analysis for the Physical Sciences , 1969 .

[153]  R. Haddon,et al.  An Earth model incorporating free earth oscillation data , 1969 .

[154]  L. Knopoff,et al.  Reduction of shock‐wave equations of state to isothermal equations of state , 1969 .

[155]  L. Knopoff,et al.  Comments on the interrelationships between Grüneisen's parameter and shock and isothermal equations of state , 1969 .

[156]  Eugene Herrin,et al.  Introduction to “1968 seismological tables for P phases” , 1968 .

[157]  M. Nafi Toksöz,et al.  P-wave velocities in the mantle below 700 km , 1967 .

[158]  J. Verhoogen.  Phase changes and convection in the Earth’s mantle , 1965, Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences.

[159]  S. Shtrikman,et al.  A variational approach to the theory of the elastic behaviour of multiphase materials , 1963 .

[160]  H. Callen.  Thermodynamics and an Introduction to Thermostatistics , 1988 .

[161]  B. Skinner.  Physical properties of end-members of the garnet group , 1956 .

[162]  F. Birch.  Elasticity and Constitution of the Earth's Interior , 1952 .