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"Dried Mud Flats" Interpretation Sign Jeffers Petroglyphs Historic Site ~ Comfrey, Minnesota

These mud flats were created by sediment deposited by flood waters. Heavier sediment, such as sand, drops out first. The silt & lighter mud is deposited. This mud flat dried & cracked in hexagonal shaped in the sun after flood water receded, over a million years ago. It was then covered with layers of sediments which preserved the cracked appearance. Many layers of sediments produced pressure over millions of years & created the Sioux Quartzite that we see today. :)

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Uploaded on April 22, 2020
Taken on August 25, 2016