noun
erratic
A rock carried from its original location and left behind by a glacier.
A large erratic rests in the field above the valley.
Etymology
The Latin verb means to wander. A glacial erratic appears to have wandered from its source rock, having been transported and deposited by moving ice.
More examples
- The glacier left this erratic behind when it melted.
- This granite erratic differs from the local bedrock.
- Geologists use erratics to trace the paths of ancient glaciers.
Forms
Similar words
- glacial erratic
- Explicitly names the glacier responsible for moving the rock.
- boulder
- Describes a large rock without specifying how it arrived.