The Work of Ice Age Glaciers

Pictured are glacial grooves on Kelley's Island in Lake Erie.  This is the work of Ice Age glaciers.  Here is a quote from my book, the Dynamic Great Lakes:

The glaciers ground softer rocks into smaller and smaller pieces.

The underside of the glacier picked up sharp pieces of stone and

rasped them across the earth. The glacier rasped polished grooves in

hard rock along Lake Superior’s northern shore and other places

such as Kelley’s Island in Lake Erie.

Some Ice Age glaciers remain in northern Canada and Greenland.  The Dynamic Great Lakes is available at Barnes & Noble, Amazon.com and many other online stores and fine bookstores.