The force per unit area acting on a material and tending to change its dimensions, i.e., to cause a strain. The two main types of stress are direct or normal (i.e., tensile or compressive) stress and
shear stress.
Stress regimes are shear zones. A shear zone or shear is a wide zone of distributed shearing in rock. Typically this is a type of fault but it may be difficult to place a distinct fault plane into the
shear zone. Shear zones may form zones of much more intense foliation, deformation, and folding. [Wikipedia]
Linear fine scratches formed by the abrasive effect of debris-rich ice sliding over bedrock. Intersecting sets of striae are formed as stones are rotated, or if the direction of flow over bedrock chan
ges. Or Striae
Striations are the scratches etched into the rock at the bed of a glacier. Their presence indicates grinding of sand and rock particles into the bed under considerable pressure. Glacier ice alone is t
oo soft to be a powerful rock-cutting agent. Many glaciers are armed with rock fragments embedded within the ice that are effective cutting tools. The rock-choked ice grazes over the glacier bed, removign rock obstacles and leaving the bedrock rounded and smoothed. In some places fine-grained debris polishes the bedrock to a lustrous surface finish called glacial polish. Coarser rocks may gouge scratches called striations.
Multiple, generally parallel, linear grooves, carved by rocks frozen in the bed of a glacier into the bedrock over which it flows. Grooves of scratches found in surface rock that are the result of gla
cial abrasion.