Constraints on Mantle Composition from 1D Earth Models

2007 Vlab/EGC Workshop

ESS BuildingSUNY Stony BrookStony Brook, NY 11794

Baosheng Li

Supported by National Science Foundation

Structure of the Earth

Upper mantle and Transition Zone: Low velocity zone, discontinuities;Lower Mantle: Phase transition at D”

PREMDziewonski and Anderson (1981)

Mantle OC IC

(Ringwood, 1975)(Ringwood, 1975)

Mineralogy and Chemical Composition Models of the Mantle

Thermoelasticity for mantle minerals/phases

Mineral Assemblage in the mantle

Adiabatically or isothermally raise pressure to deeper depths

Mixing of all phases (VRH, HS, etc)

Constraints on the Earth’s Interior: Forward Modelling

Bass and Anderson (1984)

Composition: Pyrolite and Piclogite

Bass and Anderson (1984)

Blue: Piclogite ; Red: Pyrolite

Comparison of the P and S wave velocities for olivine and wadsleyite at 410 km depth

W. Liu, J. Kung and B. Li (GRL,2005)

Duffy and Anderson (JGR, 1989)

Thermoelasticity of Mantle Minerals

Stixrude and Lithgow-Bertelloni (2005)

Velocity of Mantle Minerals at Mantle Depths

B. Li and R. C. Liebermann (PNAS, 2007)

Phase Fraction of Pyrolite in the Mantle

Stixrude and Lithgow-Bertelloni (2005)

Phase Assemblage of Piclogite in the Mantle

Stixrude and Lithgow-Bertelloni (G J I, 2005)

B. Li and R. C. Liebermann (PNAS, 2007)

Ita and Stixrude (1992)

PREMPyrolitePiclogite

Blue: 1500KRed: 1600K

Stixrude and Lithgow-Bertelloni (2005)

Comparison of Pyrolite with 1-DPREM/AK135

•Simultaneous Vp, Vs, comparison for tight constraints

4.2

4.6

5

5.4

5.8

700 1200 1700 2200 2700

Depth (km)

Density (g/cm3)

Pyrolite

PREM

AK1359.50

10.50

11.50

12.50

13.50

14.50

700 1100 1500 1900 2300 2700

Depth (km)

Velocity (km/s)

Pyrolite

AK135

PREM

Mg-Pv

Mw

5.20

5.70

6.20

6.70

7.20

7.70

700 1200 1700 2200 2700

Depth (km)

Velocity(km/s)

PyroliteAK135PREMMg-PvMw

7

B. Li and J. Zhang (PEPI, 2005)

See also Zhao&Anderson (1994), Jackson (1998)Hamma and Anderson (2002); Stacey(1996); Murakami et al(2007)