exchemist
Veteran Member
Oh thanks for correcting me, I had thought they were usually due to water.I was going to say earlier that most of those formations tend to be glacial, but there can be other causes. When it comes to giant kettles found on top of hills, or on areas such as Canada's shield granite, those are almost always from glacial origins.
Does the movement of ice over the top cause a rock inside to grind it out, like a mortar and pestle, or something?