Jump to main content.  Great Minds, Great Lakes   Social Studies
The Journey of the Great Lakes    Learn More  Where did the
Great Lakes Come From?   Tall Ship Logo  The story begins about
three billion years ago. This lesson condenses and describes
millions of years of geologic history to help you appreciate how
long it took to form the Great Lakes and the origin of its many
treasures, including rich mineral deposits.  During the
Precambrian Era, which started about 3 billion years ago and
ended 600 million years ago, a great deal of volcanic activity
occurred. This actions and sedimentary deposits were the source
of the rich mineral deposits found in this region. During the
Precambrian Era, the only types of life existing on the Earth
were algae, fungi, and bacteria.  After billions of years of
volcanic activity, central North America was flooded several
times during the Paleozoic Era., which lasted more than 350,000
million years. The flooding brought different soil materials,
such as mud, clay, and sand,