Pressure dependences of elastic moduli for geophysical minerals using the Stacey equation of state

The reciprocal K prime EOS due to Stacey has been found to describe adequately behaviour of materials at extreme compression. We have generalized the Stacey equation of state to compute the pressure dependences of elastic moduli for geophysical minerals such as MgO and MgSiO3 Perovskite. We have used the method adopted by Tallon for generalizing the expressions of different elastic moduli. It has been assumed that the individual elastic moduli change with pressure/compression in a manner similar to the change in bulk modulus. It is found that the results obtained in the present study for C-11,C-12 and C-44 in case of MgO and C-11,C-12, C-13, C-22, C-23, C-33 in case of MgSiO3 Perovskite are in close agreement with the available data, however, C-44, C-33 and C-66 for MgSiO3 Perovskite present less satisfactory agreement with the available data.