CHICAGO — As an ice sheet thousands of feet thick began its final crawling retreat from North America to the Arctic toward the end of the last glacial period some 10,000 years ago, it left behind the ...
The Great Lakes formed where they did 20,000 years ago thanks to a hotspot that sat under the supercontinent Pangaea 300 million years ago, before North America even existed. New research finds that ...
As an ice sheet thousands of feet thick began its final crawling retreat from North America to the Arctic toward the end of the last glacial period some 10,000 years ago, it left behind the planet’s ...
Powerful pulses of groundwater flow up from beneath Lakes Michigan and Huron, which together form one of the largest ...
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