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.
Catoctin Columns
August 5, 2016 by ·
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The Defenses of Yorktown
Yorktown became a famous locale in 1781 after the surrender of the British troops which effectively ended the Revolutionary War. British forces in and around Yorktown dug a number of defensive earthworks that were sieged by American and French troops over a three-week period prior to the surrender on October 19th, 1781. In the early 21st […]
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Virginia is for Lavas- The Catoctin Formation
Many of the highest peaks in Shenandoah National Park (including Hawksbill, Stony Man, and Hightop Mountain, just to name a few) are underlain by distinctive bluish-green rocks that were once ancient lava flows (Virginia is for Lavas!), and are part of a geologic unit known as the Catoctin Formation. From the presidential retreat at Camp David to Jefferson’s […]