Lily and I took a hike yesterday over Old Rag Mountain, a popular destination in Shenandoah National Park. I took the opportunity to shoot a few gigapan images of the scene. If you click on the word “Gigapan” in the lower right of any of these images, it will take you to gigapan.org’s full page viewer.
Once we got above the trees, this was the view to the north:
This was the scene looking west at the second big uphill rock “scramble,” with the mountain’s summit in the distance at the right:
Lastly, check out these opferkessel atop on of the granite outcrops:
There! It’s just like hiking the mountain yourself, except that your legs are a lot less sore than mine are.
These remind me of the “solution pits” on Stone Mountain and nearby granitic gneiss pavement outcrops.
Have you seen this article (or a similar one from Earth magazine) about how Native Americans used them for salt production?
http://pubs.usgs.gov/sir/2009/5225/
The edges on the ones in your photos look like the artificially enlarged ones.
Probably the same thing, except this is no doubt hydrolysis of feldspar and frost wedging that makes them bigger, not dissolution.
Amazing how that one area of exposed granite outcrops look so much like the rock scrambling you find everywhere in the Wonderland of Rocks in Joshua Tree, with the foliage providing the different look.