A Volcano in Wisconsin?

July 8, 2011 3 Comments

WATCH THE VIDEO: Wandering Wisconsin: Dells of the Eau Claire

Dells of the Eau Claire

Dells of the Eau Claire

Our state has a very interesting geologic history. 

Though you wouldn’t know it when driving through the rolling Wisconsin hills dotted with dairy farms, at one point a long time ago things looked a little different. 

Geologists believe that about two billion years ago massive volcanoes were centered in what we know today as Marathon County!  Why do they think that?  The Dells of the Eau Claire

Dells of the Eau ClaireWhen the lava from these ancient volcanoes hardened into rhyolite–some of the hardest rocks on the planet–millions of years of tectonic shifting tilted that horizontal rock vertically.  That’s how today we see those beautiful chunks of rocks bolt from the ground seemingly soaring toward the sky.   

But wait…where did the volcanoes go then?  

Dells of the Eau ClaireThe glaciers steamrolled those volcanoes when they retreated northward, whittling them down to smooth rolling hills.  Glacial melting provided the water needed to erode away sections into the Eau Claire River, giving us what we see today.  Few places on earth can you see naturally occuring square rock formations paried with smooth circular edges because of sand and water erosion. 

For more information on Dells of the Eau Claire and the other parks in the Marathon County Parks family, visit them online here.

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  1. gentrey cram says:

    if this volcano is so beautiful then how come scintist belive that if it erupts this year from the eaths current pull that it’ll put us in the ice age thousands of years. the cause of all the massive smoke blocking out the sun that means no solar power, no electristity an no gas beacuse the ground will be so frozen a drill couldnt dig it up! If think im lying then huke me up or search it NASA.NET

  2. Hello.
    I live in Madison, WI.
    I was wondering about this volcano. My questions are, 1. When was the last time it erupted and 2. Is there any truth to the rumor that it will erupt again within the next 20 years?
    This last question leads me to number 3. Are the citisens in Madison in any danger of this eruption because we are many miles from Marathon County?

  3. jloew says:

    Don’t worry, there is no immediate danger from any ancient volcanoes here in Wisconsin. There is no sign of any eruptions at all. Maybe hundreds or thousands of years from now there will be volcanic activity again.

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