Smithsonion Report. 1952.— Flint 



Plate 4 



Glaciated Areas in North America. Generalized To Show the Maximum 

 Area Covered Regardless of Date of Glaciation 



Reproduced by permission from Textbook of Geology, Part 1, by Longwell, Knopf, and 

 ' Flint, published by John Wiley & Sons. 



* ' 



