Glacial erratics



Boulders are used as educational tools and garden accents in the landscaping surrounding the new Great Lakes Research Center along the waterfront at Michigan Tech.  Some of the boulders, which came from the Boulder site, are unlike any rocks found in outcrops anywhere around here.  The rock types include: 1. High grade metamorphic gniess, which forms only deep in the earth’s crust and 2. Submarine volcanic breccia, with volcanic rock fragments in a muddy matrix.  The likely source region for these rocks is Ontario or Quebec, and they could have been transported more than 1000 miles.

At this site there are about 15 boulders scattered around the building. Identify the Canadian aliens.


Glacial Boulders can be from far away


Question:  How might erratics differ in shape from more local boulders?