@archonforest: rotating has nothing to do with the blues, you can just use an ordinary transform shader, rotate X(Y)Z by 90ยบ and merge that with the original (or add as child for 50% or so, lots of ways). Now if you mask that by some vertical billow you may get interesting shapes, where the squares only appear where the billows are and you have some smoother gullies left over, which give the appearance of erosion. Just play with it.
By the way; the same principle goes for mogn's square blues setup from a while ago, though that's a little more nodes, but also more variation.