Kelley's Island Glacial Grooves
The grooves which are mostly straight, are marked in many places with some interesting details. The most noticeable is the winding swirls found in some of the smaller grooves.
There are also some sections where the rock seems to be undercut, and places where the formations indicate that the ice flowed around large melon-shaped knobs.
When the grooves were uncovered for the first time, a high polish was noticed on some of the rocks. This polish was most likely produced by the scraping of clay. Soon after the rock was exposed the polish disappeared to weathering. Weathering also caused the pitted effect noticed on some parts of the grooves. It is believed that these pitted areas were exposed to the weather once before, thousands of years ago, and were then re-covered.
