Glacial striations are grooves or scratches carved into bedrock by rocks embedded in the base of a moving glacier. These striations are aligned with the direction of ice flow and provide important evidence of past glacial movement. Studying glacial striations helps geologists reconstruct ice flow patterns and understand the dynamics of ancient ice sheets.
Reference: Boulton, G. S. (1974). Processes and Patterns of Glacial Erosion. Progress in Physical Geography.