Contrasting dilatant behaviors of mafic and ultramafic rocks based on triaxial deformation experiments

We performed triaxial deformation experiments on cylindrical specimens of mafic and ultramafic rocks to quantify their dilatant behaviors. Experiments were performed using an intra–vessel deformation and fluid flow apparatus at room temperature, a constant strain rate of ~ 10−6 s−1, and a confining pressure of 20 MPa. Axial and radial strains were monitored using strain gauges glued to the specimens. The onset of dilatancy of mafic rocks ranged...