DYNAMIC PROPERTIES OF ROCKS

Abstract

Abstract : Hugoniot equation of state data in the pressure range 5 to 150 kb have been obtained for quartzite, sandstone, calcite, marble, limestone, plagioclase, and basalt. The data were obtained by conventional shock wave techniques which measure shock and associated free-surface velocities. Impedance match solutions were obtained for porous rocks. High values of the Hugoniot elastic limit were observed in solid rocks-50 to 100 kb in quartzite, 40 to 50 kb in feldspar and basalt, and 20 kb in calcite and marble. Porous rocks show considerable reduced values amounting to approximately 5 kb in sandstone and limestone. Four phase transitions, indicated by multiple shock fronts, are observed in calcite. No simple relation between these and the reported transitions observed in static experiments in evident. An indication of a phase transition in sandstone at 68 kb was also obtained and is interpreted as the quartz-stishovite transition. Decay of the elastic precursor wave amplitude, implying a time-dependent yield stress, is observed in quartzite, calcite, and marble.