Wazee Lake: Geology

© Photographed August 31, 2015
Black River Falls, Jackson County, Wisconsin
44.294386,-90.72651 (marker location)
44.291891,-90.731949 (park entrance)

GEOLOGY
The Black River Falls iron ore deposits lie a considerable distance from the principle U.S. iron ranges of northern Minnesota, Wisconsin and Michigan. Geologically, the Black River Falls deposits are different in that they are much older than most of the deposits in the principle ranges.

The geologic history of the Black River iron deposits begin about 2.5 billion years ago around the undersea flanks of a large volcanic island. During a very long period of quiet between volcanic eruption, various slides and iron-bearing materials were precipitated from sea water as mud like layers on the sea floor. When several hundred feet of these iron rich materials had accumulated, the volcano became active again and buried them under many feet of volcanic ash.

Subtle movements of the earth's plates caused the buried volcanic ash and iron rich sediments to be squeezed and wrinkled into a range of "mountains". The soft iron bearing sediments were converted by heat and pressure to a dark colored shyst rock (iron ore) that is found throughout the site today. Millions of years of erosion and glaciation caused the mountains to be worn flat, leaving only the hard iron deposits standing as low hills above the plain, much as we see today.

The ore body that was mined here is the remains of one folded, tilted iron deposit that began on the flanks of that volcano, billions of years ago.
The marker is located at the parking lot adjacent to the Fox Point Overlook at Wazee Lake Recreation Area. The entrance to the park is located at N6302 Brockway Road, Black River Falls, Wisconsin 54615.

NOTE: Wazee Lake Recreation Area requires a fee to enter.

The lake is 146 acres in size and is the clearest and deepest inland lake in Wisconsin.Wazee Lake has become the most popular scuba diving site in the Midwest, attracting more than 1000 divers annually.

"Wazee" means "tall pine" in the Ho-Chunk language.

See also, Wazee Lake Recreation Area, also at this location.

With Lake Wazee in the background.




The marker is at the parking lot for the Fox Point Scenic Overlook.



Follow the signs to the Scenic Overlooks.

The fee entrance to Wazee Lake Recreation Area.

The marker is located at Wazee Lake Recreation Area.

The marker is located at Wazee Lake County Park
in Black River Falls, Wisconsin.

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