The Great lakes went through glaciation many thousands of years ago.
Glaciation
The Great Lakes are more the result of glaciation than plate tectonics.
Some of the features created by glaciers in North America include the Great Lakes, Niagara Falls, Yosemite Valley, and the Finger Lakes in New York. These features were formed through the process of glaciation during the last Ice Age.
The Canadian Shield
The Great Lakes and the Finger Lakes were carved by ice glaciation in the valleys. Lakes in Minnesota and Wisconsin were gouged out by glaciers and later filled with water from melting glaciers. Niagara falls was formed when the glaciers created dams on the rivers and changed the flow.
An extensive, late Paleozoic glaciation affected southern India, southern Africa and southeastern South America.
Glaciation played a crucial role in the formation of the Great Lakes during the last Ice Age, around 10,000 to 15,000 years ago. As massive glaciers advanced and retreated, they carved out deep basins in the Earth's crust. Melting glaciers filled these basins with water, creating the Great Lakes we see today. This process also shaped the surrounding landscapes, contributing to the lakes' current size and geography.
Glaciers carved out the basins of the Great Lakes and the St. Lawrence Lowlands as they advanced and retreated, depositing sediment and shaping the landscape. As the glaciers melted, they filled the basins with water, creating the Great Lakes. The St. Lawrence Lowlands were also formed by glacial action, with the retreating ice leaving behind fertile soil and a flat topography suitable for agriculture.
Glaciers changed the face of North America with the following effects:An ice sheet covered most of Canada.The southwest received heavy rains.
The Canadian shield
Glaciation on interior plains can create unique landforms like drumlins, eskers, and outwash plains. The movement of glaciers can shape the landscape by depositing sediment and carving out valleys. Glaciation also leads to the formation of lakes and wetlands in the region.