How was the Gulf of St Lawrence formed?

The Gulf of St. Lawrence was formed primarily through glacial erosion and melting during the last Ice Age, approximately 12,000 years ago. As glaciers advanced and retreated, they carved out the landscape, creating deep basins and channels. The melting ice then filled these depressions with seawater, leading to the formation of the Gulf. Additionally, the rise in sea levels contributed to flooding coastal areas, further defining the Gulf's current shape and size.