The work of John Bluemle PhD

Lake sediment near Mayville

glacial lake sediments, North Dakota, geology

Evenly bedded sediments of Glacial Lake Agassiz, south side of Mayville, Traill County. The light-colored beds of silt are about 5 inches thick. They are separated by thinner dark bands. The light-colored bands were deposited on the floor of the lake during a single summer season, the dark bands during a winter. During the summer, steams flowing into the lake carried large amounts of silt, which accumulated in thicker layers on the lake floor. In the winters, the amount of incoming sediment was much less. The layers shown here record about 15 years of Lake Agassiz’s history.

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