WATER - How were the Great Lakes formed?

Having grown up in Wisconsin, I've heard a lot about the Great Lakes. That being said, a new question was brought to mind during class the other day. In class we were learning about how lakes were formed, and that made me wonder what it was that carved out these massive lakes. 

http://www.greatlakesnorthamerica.com/howthegreatlakes.html

The site above is what I used to find my information.

According to this site, the primary cause for the formation of these lakes is glacial erosion. Around 14,000 years ago, the Lauren Tide (a mass of glaciers covering most of Canada and northern parts of the US), started to shift to the South as the climate warmed and they continued to melt and refreeze. Eventually the glaciers carved out the massive indentations that would slowly (via rain and the glacier melting as it passed) fill with water and become the Great Lakes that we now know.

EXTREMOPHILES

THERMOPHILES

Found in geothermally heated regions of the earth, Thermophiles can survive between 115 and 175 degrees Fahrenheit. They can be found in hot springs like those in Yellowstone National Park.

ACIDOPHILES

Like thermophiles, acidophiles can survive in extreme conditions. Their specialty isn't necessarily heat though. They can survive in extremely acidic conditions. Most of the time with a pH level of 2.0 or below. They are usually bacteria type organisms.

HALOPHILES

Like the other 2, halophiles are also usually bacteria type organisms. They can survive in extremely salty conditions. In comparison, most similar type organisms would dissolve or not be able to function properly in such salty conditions. They are very prominent in salty bodies of water like the Great Salt Lake in Utah.