New equation of state data for a weathered granite shocked to about 125 GPa are reported and combined with the Westerly granite data of McQueen, Marsh & Fritz (1967). The shock velocity (Us)‐particle velocity (Up) relations can be fitted with two linear regressions: Us= 4.40 + 0.6Up for a range of Up up to about 2 km s‐1 and Us= 2.66 + 1.49Up for a range of about 2 to 5 km s‐1. The third‐order Birch‐Murnaghan equation of state parameters are Kos= 51‐57 GPa and K'os= 1.4‐1.8 for the low‐pressure regime and Kos= 251 ± 30 GPa and an assumed K'os= 4 for the high‐pressure regime. Compressive waveforms in dry and water‐saturated granite were measured at 10‐15 GPa using the VISAR technique. The measured wave profiles were successfully modelled using a Maxwellian stress‐relaxation material model. Water‐saturated granite is characterized by a ˜25 per cent lower yield strength and a ˜75 per cent longer material relaxation time than dry granite.
|Original language||English (US)|
|Number of pages||15|
|Journal||Geophysical Journal International|
|State||Published - Feb 1995|
All Science Journal Classification (ASJC) codes
- Geochemistry and Petrology
- Key words: equation of state, granite, phase transitions.