Longitudinal and lateral stress measurements in shock-loaded gabbro and granite

Plate impact experiments have been performed on two igneous rocks of differ ent grain size. Shock stresses have been measured using embedded manganin s tress gauges, up to similar to 12 GPa. In the coarser grained material data was obtained by impacting rock flyer plates onto previously characterized targets. Results are compared and contrasted to the existing data for other geological materials. In the finer-grained material lateral stress was als o measured. In combination with the longitudinal stresses, these results ha ve been used to obtain the materials shear strength under shock loading con ditions. Results suggest that the material is deforming in an inelastic man ner. (C) 2000 American Institute of Physics. [S0021-8979(00)06408-2].