Glacial striations or striae are scratches or gouges cut into bedrock by glacial abrasion. These scratches and gouges were first recognized as the result of a moving glacier in the late 18th century when Swiss alpinists first associated them with moving glaciers.

Where are striations formed?

Glacial grooves and striations are gouged or scratched into bedrock as the glacier moves downstream. Boulders and coarse gravel get trapped under the glacial ice, and abrade the land as the glacier pushes and pulls them along.

How were striations formed?

As glaciers flow over land, they incorporate pieces of rock and sediment into the ice. ... Over time, the glacier moves over rock and sediment, leaving striations or striae, on the rock surfaces that can reveal the direction that the glacier was flowing.