Catoctin Columns

Well-exposed columnar joints in the Ediacaran Catoctin Formation.  Exposure on Compton Mountain in Shenandoah National park.

Well-exposed columnar joints in the Ediacaran Catoctin Formation. These columns formed as cooling cracks as 570 to 550 Ma lava flows solidified. Exposure on Compton Mountain in Shenandoah National Park.