Template:POTD/2011-09-15
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2011 September
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Picture of the day
Mammoth Hot Springs
is a large complex of
hot springs
on a hill of
travertine
in the United States'
Yellowstone National Park
. It was created over thousands of years as hot water from the spring cooled and deposited
calcium carbonate
.
Algae
living in the warm pools have tinted the travertine shades of brown, orange, red, and green.
Photo:
Mila Zinkova
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