Page:Popular Science Monthly Volume 30.djvu/13

Rh In the country east of the Mississippi the evidence of ancient glaciation is even more wide-spread and impressive than in the far West. The surface-rocks of Canada, New England, New York, and the greater part of Ohio, Indiana, Illinois, and Wisconsin, bear marks of ice-action, and are generally covered with a sheet of drift material which has been carried from the north southward, often many hundred miles. This



glaciated and drift-covered area extends from Maine and Massachusetts in a belt parallel with the arch of the Canadian highlands five hundred miles wide and more than two thousand miles long. Its extension northward from the head-waters of the Mississippi has not been traced farther than Lake Winnipeg, where it was studied by