Final answer:
Continental glaciers have shaped more of the United States landscape than valley glaciers. The landscapes of the northern U.S. bear more marks from the wide-reaching impact of continental glaciation during the last Ice Age, which formed many of the land features present today, such as the Great Lakes and the upper Midwest’s terrain.
Step-by-step explanation:
The student is asking which type of glaciers, valley glaciers or continental glaciers, have shaped more of the landscape of the United States. To answer this, we need to understand that continental glaciers are large ice sheets that cover relatively flat ground and can be quite extensive, covering entire continents. Valley glaciers, on the other hand, are smaller and tend to be found in mountainous areas, carving U-shaped valleys as they flow downhill.
In the case of the United States, continental glaciers have had a much more significant impact on the landscape. During the last Ice Age, about 12,000 years ago, continental glaciation covered a large portion of North America, particularly in the northern parts, shaping much of the terrain. Landforms such as the Great Lakes and the upper Midwest’s gently rolling hills are remnants of this glaciation period. Glacier National Park (GNP) in Montana provides examples of the more recent effects of valley glaciers, but the extent and impact of continental glaciers far exceed those of alpine or valley glaciers in shaping the American landscape.
Soils in northern central and northeastern U.S. are relatively young due to the influence of glaciers which deposited various soil materials and created diverse topographies. Places like Cape Cod are evidence of the glacial deposits. Geological studies and observations of features such as the Manhattan schist in New York City also tell stories of ancient glacial activity.