Density of dry peridotite magma at high pressure using an X-ray absorption method

The density of a peridotite magma was measured up to 2.5 GPa and 2300 K using an X-ray absorption method. The method allowed measurement of the density of a peridotite melt under seven different conditions and clarified the pressure and temperature dependence of the density. A fit of the pressure-density-temperature data to the high-temperature Birch-Mumaghan equation of state yielded the isothermal bulk modulus, K(T0) = 24.0 +/- 1.3 GPa. its pressure derivative, K(0)' = 7.3 +/- 0.8, and the derivative of bulk modulus (partial derivative K(T)/partial derivative T)(P) = -0.0027 +/- 0.0017 GPa/K at 2100 K. The large bulk modulus and its pressure derivative of the peridotite melt compared with that of basaltic melt is consistent with previous results from sink-float experiments.