Final answer:
The Great Lakes were formed by glaciers during the last Ice Age, while the St. Lawrence Lowlands were shaped by glaciers and sediment deposits.
Step-by-step explanation:
The Great Lakes and St. Lawrence Lowlands were formed through a combination of geological processes over millions of years. The Great Lakes were created by the erosion of ancient river valleys by glaciers during the last Ice Age, approximately 14,000 years ago. As the glaciers retreated, they left behind massive depressions which filled with water, forming the Great Lakes. The St. Lawrence Lowlands, on the other hand, were shaped by the movement of glaciers over the region, which deposited layers of sediment and sculpted the landscape into a relatively flat lowland. Therefore, we can say that the lowland areas, including the landscape around the modern-day Great Lakes and the St. Lawrence River valley, were primarily formed after the significant glaciers receded around 12,000 years ago. It's also important to note the historical context provided by the colonization of these regions by French Canada, which has left a lasting cultural and linguistic mark in parts of Eastern Canada, including the St. Lawrence Lowlands, despite British conquest.