Weathering & Erosion
Boulder Field at Hickory State Park in Pennsylvania
These sandstone boulders were created by frost action, a form of physical weathering, from the Laurentide Ice Sheet during the last ice age. The water for the frost action came from the melting ice sheet whose advance stopped approximately a mile from this boulder field.
Watch a Science Friday video clip on the formation of these boulders. Choose the link below the picture on the right.