Archive for May, 2011

Millions and billions of years ago…

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 […]