Teacher Notes in Yellow

This rock, known as a glacial erratic, is an impressive example of the power of glaciers to transport materials. It's an amazing thing for us all to consider how incredibly heavy this rock is - and yet it was moved, by glacial action, probably many miles from its original source. You might use the opportunity to have your students try to find examples of glacial erratics close to their homes. Many of the large boulders found in this area were transported by glaciers.

This rock ("Big House Rock") sits on top of the soil - it is not part of the bedrock, and, in fact, is of a different type of rock (Quincy granite) than the bedrock. We're several miles from Quincy. How did this rock get here? (Before you assume that people moved it, estimate the weight of this rock. The rock is roughly 12,000 cubic feet, and its density is around 170 pounds/cubic foot!)

By the way, this rock is 37 feet high.