Millions and billions of years ago… Posted on May 5th, 2011 by

On May Day, students from GEO 111: Principles of Geology (part of the original ES major) hiked around Interstate State Park on the eastern border of Minnesota.  In the photo above, they found a rock outcrop where 1.1 billion year-old volcanic rock is directly overlain by ~500 million year-old sedimentary rock.  So, while we know that volcanoes were active at this place long long ago, and we know that there must have been an ocean depositing sandstone at the same location 600 million years later… we don’t directly know anything about what happened during all of that intervening time.  Wild!  The class was joined by Chuck Howe, a professional geologist, and his wife Mary.  Prof. Triplett kept them all in good spirits – despite the cold weather – by bringing extra donuts and other picnic food.


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