Pressure derivative of the dielectric constant of magnesite

Determine the isothermal pressure derivative of the relative dielectric constant of magnesite (MgCO3) over relevant pressure ranges to enable accurate modeling of interfacial polarization and relaxation in water-saturated magnesite using effective medium approximations.

Background

In the effective medium analysis of interfacial polarization for water-saturated rocks, the pressure dependence of the relaxation frequency depends on the pressure derivatives of the constituent phases’ dielectric constants and conductivities. For calcite, the pressure derivative of the dielectric constant is available from prior studies, but for magnesite it is missing.

To proceed with calculations for magnesite, the authors assume the pressure derivative of magnesite’s dielectric constant is comparable to calcite’s, introducing uncertainty into predicted activation volumes and relaxation behavior. Direct measurement or determination of this derivative would remove the reliance on assumptions and refine theoretical predictions.