Glacial erratics are stones and rocks that were transported by a glacier, and then left behind after the glacier melted. Erratics can be carried for hundreds of kilometers, and can range in size from pebbles to large boulders.

How are erratics deposited?

Glacial erratics, often simply called erratics, or erratic boulders, are rocks that have been transported by ice and deposited elsewhere. ... For example, an erratic could be a boulder of sandstone is picked up by a glacier, transported, and deposited on top of a limestone bedrock.

How far can glacial erratics travel?

The distance of transportation may range from less than 1 km (0.6 mile) to more than 800 km (500 miles); those transported over long distances generally consist of rock resistant to the shattering and grinding effects of glacial transport.