Well, I am doggedly pursuing this and in a stroke of perhaps madness I decided to make a mask from a multi coloured Painted shader, well white, very light, .25 power and white at 1, plus a full red stroke and this is the terrain. The renders are from opposite ends of one of the canyons that happened. I used the map as a Mask for the Fractal Warp, and Distribution shaders for everything else. I've attached a screen grab of the Painted shader and a top view of the terrain with cameras. C&C moist welcome