The process through which great lakes were formed in the past.
Answer to Problem 1RQ
Great Lakes were formed due to the melting of glaciers and erosion of ice sheet of North America. The melted water drained into the depression and contributed to the formation of the lake.
Explanation of Solution
About 22,000 years ago, the continental glacier started to melt. The water from the continental glacier flowed towards the ocean and raised the levels of oceans. According to geological studies, it has been revealed that the temperature in the rocky mountains had also increased during that time. It caused the melting of the ice sheet of North America.
The water drained from the ice sheet flowed from the southern border and lead to the formation of lakes. These lakes were known as the great lakes. So, the great lakes were created by erosion of large ice sheet and melting of glaciers. Some examples of great prehistoric lakes are lake Nippising, lake Chippewa, and lake Algonquin.