The Hans Hofmann Hall of the Pointe de Buisson Archeological Park, #Beauharnois (across the river and upstream from #Montreal). It contains large blocks of Cambrian Potsdam sandstone containing trace fossils. In front is the rock and a cast of Climactichnites, a slug-like mollusc feeding in the tidal zone. #FossilFriday #EarthSystemScience #McGillUniversity