 An example is the large pothole found in Archbald, Pennsylvania, in Archbald Pothole State Park.Giant's kettles are formed while a bedrock surface is covered by a glacier.Water, produced by the thawing of the ice and snow, forms streams on the surface of the glacier, which, having gathered into their courses a certain amount of morainic debris, finally flow down a crevasse as a swirling cascade or moulin.