What factors led to the emergence of the Great Lakes-St.Lawrence provinces as Canada's heartland?

How do gerbils live in the Sahara desert? What river flows through damascus? When examining rocks from both sides of the mid Atlantic ridgescientist found evidence for the phenomenon of? Name the trail the pioneers used to come to the Salt Lake Valley? What cities are near Laughlin? How many acres are there in Hollywood studios? How much are the tickets for island water park in Fresno? When was Lincoln Park Zoo created? What region did the great orator Daniel wedster represent? Standard Concrete Block Sizes? What is the name of the man-made lake? When does thorpe park open? What 550 BC which leader began the Persian Empire along the north east cost of the Persian Gulf? Which continent has the most existing desert? What are the defensive features of Bodiam castle? What river did the dutch take control of as a result of searching for the nothwest passaga? The small organism that actually builds the reef is called a? Where is the Ku Natural History Museum in Lawrence Kansas located? Which Indian state has the minimum forest cover? Where are oxbow lakes found?

What factors led to the emergence of the Great Lakes-St.Lawrence provinces as Canada's heartland?