Eric, you must have studied geology!
Ha! That is a laugh.
Whenever I visit a National Park, I generally at some point attend one of the park naturalist's talks on geology, and I always find it quite fascinating. And by the time I leave the park I've forgotten just about everything I heard. That's what makes the next talk just as interesting.
Here's what I think I remember abut geology at this point in time: Glacier-formed valleys are usually U-shaped, while river-formed ones are V-shaped (or is it the other way around?). My vast vocabulary of geologic terms includes (and is pretty much limited to): "granite," "schist," and "basalt." Isn't that gneiss?
Your photo is a different view of the GC from any I've seen, although it sure looks like something from the Southwestern U.S.
As for Terry's feeling of being "cut off without somewhere to 'go' in the photo," I think that is part of the expressive appeal of this image for me, because it is so difficult to go cross country in canyon lands; there's always another ridge to cross with an impossible drop on the other side, etc., etc.
The photo expresses this ambiguity for me very well: the warm colors invite you in, but the layer upon layer of cross-wise ridges send the message that "you can't get there from here."
I wish I'd taken that shot.
Cheers,
Eric