Kettle, Butler County
This pond visible from the top of the Jacksville Esker on Swope Road is a kettle. A kettle forms when a block of glacier ice breaks off from the front of the glacier during its retreat, and is buried by the sediment released from the glacier during melting. The ice block melts, leaving a depression in the landscape. They are called kettles because of the similarity in shape to the kitchen utensil called a kettle. They gradually fill with sediment and vegetation encroaches upon them. This kettle pond probably originally covered all of the non-wooded area in this photo, but is gradually being filled and vegetated.
Most natural lakes and ponds in northwestern Pennsylvania are kettles.
Photo by Gary Fleeger, PaGS.