Those will be difficult in WM. In the real world they were shaped primarily by glacial erosion and secondarily by fracture (spalling/exfoliation) of exposed rock surfaces. WM doesn't have a node to do that.
However, if I were trying this, I would start with an Advanced Perlin Noise node using the Sharp Ridged mode and a substantial Steepness. I'd start with the default Octaves and then experiment with the Persistence setting. Once you get something approximately to your liking, there are many, many options for fine tuning in the Advanced Perline Noise node.