Loads and deformations were recorded throughout the tests. Lateral strains were determined from radial deformations taken in two normal directions (i.e. along two perpendicular diameters) at the midpoint of the specimen. Being able to measure diametrical deformations at only two locations is an equipment limitation that has interesting consequences when testing composite layered rocks with halite layers. At a given value of σ3 and strain rate, halite may behave viscoplastically, while strong adjacent interlayers behave in a brittle manner. Ideally, in a specimen of variable lithology along the axis, the local distribution of axial and radial strains should be gathered along the entire length or at least the central 60% to gain insight into relative deformability and interlayer radial strain concentration. This is technically highly challenging, and we hope to include this in the future; nevertheless, midpoint diametrical deformations can still be employed to illustrate mechanical differences among lithologies for different specimens. Specimen data are listed in