Shock wave equations of state of chondritic meteorites

We have obtained shock compression data for Murchison and Bruderheim chondritic meteorites. Data for Murchison suggest that the Hugoniot states are described by a smooth curve to ≥90 GPa, having ρ_0=2.656 Mg/m^3, K_(S0)=24.2±.7 GPa, K′=4.17±.10, and constant γ=1.0. The data for Bruderheim suggest more complicated behavior. A mineral mixture model consistent with the Bruderheim data suggests that the Hugoniot state is a low pressure phase below 25 GPa, with ρ_0=3.555 Mg/m^3, K_(S0)=146 GPa, K′=2.53, and constant ργ=7.11 Mg/m^3; and a high pressure phase above 65 GPa, with ρ_0=4.40 Mg/m^3, K_(S0)=225 GPa, K′=3.25, and constant ργ=7.485 Mg/m^3.