Tag Archives: glacial rock

Riddle of Rocks

When is a multi-ton boulder that has stood in place for the last 18,000 years considered erratic? If it was carried by a glacial far from its place of origin and dropped in an area where its composition is different than the surrounding native stone, geologists call the rock an “erratic” from the latin verb “errare,” meaning to wander.

Westwoods is riddled with large isolated boulders. However, most if not all have the same composition as the bedrock beneath them so technically, they are not erratics. Still, these mega-rocks were carried by monstrous glaciers from the last Ice Age and dropped helter-skelter wherever the physics of melting ice demanded, so their placement is definitely eccentric, whimsical, and capricious. Dare we say erratic?

Erratic boulder