Issue Information

Cover Photograph: Stereo optical (left) and stitched secondary-electron scanning electron (right) microscopy (OM and SEM, respectively) images of a polished cross-section of a dynamic, radially-compacted (annular) alpha-quartz specimen. The arrows in the OM image highlight several examples of produced shear bands that can be challenging to expose with reflected-light OM owing to the material's translucency but whose several-mm-long bands show good contrast with SEM. The shear bands contain vitreous silica that formed due to the test's very rapid imposition of shear-based consolidation of the alpha-quartz's original granular form and consequential localized friction and high temperature.