Figure 5. Shallow glacial grooves on granite ledges can be especially difficult to see when the ledges are dry and the sun is overhead. This photo shows an example at the south end of the beach at Birch Point State Park in Owl's Head. The grooves on this ledge show much better when the rock surface is wet, as seen here. They indicate ice flow to the south-southeast (156°).
Last updated on July 9, 2012