Very nice. I see what you mean about the layers of foam. I've had that problem in the past and I did not find a satisfying solution. One thing I thought off was gluing foam of different widths together. The idea here was to make a stratified rock formation:http://1.bp.blogspot.com/_ij0EaZSMnWI/SLWCMLVFfuI/AAAAAAAAA14/13-xhbP8e-A/s400/P8140725.JPGThomas Whittenhttp://allthingsontheworkbench.blogspot.com/
I should add that close-up looks magnificent.