14 November 2011
After my talk Wednesday night to the Potomac Appalachian Trail Club, I got an email from PATC member Tom Johnson, with an extraordinary photo attached. It shows an exceptional outcrop of the Neoproterozoic Catoctin Formation, exposed atop Compton Peak in northern Shenandoah National Park, Virginia. The outcrop features enormous, well-preserved cooling columns from these ancient meta-lava flows.
Click on it for the full-size version (posted here with Tom’s permission). You know that I’ll be visiting this in person at the first possible opportunity.