WM cannot create overhangs, so you can’t reproduce the areas where the slate sticks out over the sand. That’s inherent to the heightmap format.
For the slate, the terrace node is the place to start. The slate looks like a cap layer over some other softer rock, so you might limit/mask the terrace effect to just the higher elevations. After getting something that looked reasonable, I think I’d throw in a “spidery” or “ridge-y” noise to break up the masses of slate.
For the sand, you have a couple of approaches to try. You could crank up erosion really high and use the sediment deposits as the sand. Or you could use a separate low frequency terrain node and blend/mask that in to the rockier terrain. Take the max of the sand and rock terrains, maybe. Might identify the slate areas first, then taper the sand amplitude down to zero as it approaches slate (via masking and feathering/making-gradual the edges of the masks).
I think I would apply the terrace node after the sand/rock blending, but that might that’s just an initial guess at what would work.
For the rubble, add in a very high frequency, low-and-clamped amplitude noise in selected regions. In that photo, those regions would be elevations just under the bottom of the slate threshold.
That’s all off the top of my head. Be very interested to see what you come up with!