Blackrock Summit, a follow-up

When I wrote the original post on the Blackrock Summit hike (http://hawksbillcabin.blogspot.com/2009/10/balckrock-summit-easy-shenandoah.html) I meant to include a few highlights or anecdotes from the Heatwole guide.

Rather than interpreting any of the material Henry Heatwole wrote about the mountain, today I am simply posting quotes from his guide on one of the legends about this mountain and the geology.

• Legend: In the spring of 1781, during the American Revolution, the British were pressing westward in Virginia. The Virginia Assembly, to avoid capture, fled across the mountain to Staunton. Thomas Jefferson, governor of Virginia, entrusted the State Archives and Great Seal to his friend Bernis Brown. Bernis hid them in a cave here at Blackrock, where they remained throughout the rest of the war.
  
• Geology: Blackrock summit and the talus slopes below it are Hampton quartzite. Maybe you can imagine the great monolith that all this started from. When it was exposed by erosion it had already been cracked and weakened by pressure, and by cycles of heating and cooling. Rain water seeped into the cracks and froze, and melted and seeped and froze again. In a very short time, as geologists measure—probably less than 100,000 years—Blackrock crumbled into the magnificent but messy pile you're standing on.
  In a fresh break, the quartzite is medium salt-and-pepper gray. Weathering has stained its surface pale purplish gray-brown, tan, and red-brown. Many of the rocks are covered with close-clinging pale green lichen. (A photographer with a closeup lens, color film, and a taste for abstract art, could spend some time here.) Any blackness that Blackrock may have is due to its burden of rock tripe—a coarse lichen that's dark brown and crispy when it's dry, and gray- green and leathery when it's wet.

If you've never checked out Henry's work, "Guide to Shenandoah National Park and Skyline Drive," it is well worth the time. In stops at the visitors centers throughout the Park, sometimes a ranger will refer to the guide when asked about some more obscure trails or features, as recently happened to me when I chatted with Ranger Mike at Dickey Ridge.

As I understand it, this meticulously researched and written guide is long out of print and very hard to find in hardcopy. It can be found on-line at http://ajheatwole.com/guide/ - if you have a fond memory of a location or experience in the Park, this is a good place to check for additional background that might be available.