I can't share a tgc as it has some new nodes, but it's quite easy actually. I used a default shader as basis for color and displacement input, which is used as texture for 10m stones.
Inside the default shader I made 2 lines of PF's; one for color input, one for displacement input. The one for color input has some colored fractal mixes and 2 added surface shaders (for ochre and greenish-grey colors) set to 50% coverage and blended by some 'lichen' PF's (hard, small billows, a bit warped).
The displacement line is a small scale (2/10/0.1) warped billow fractal with Z and Z stretched x3 (color roughnes set to 1), then 2 transform shaders, then a merge shader. The first transform shader is set to rotate Z by 80 degrees, the second to rotate 20/50/-90, and change the fractal XYZ scalars by 0.15/4/0.15, thus changing the fractal from horizontal to vertical. Then mix normal or play with versions. Finally I merged a tiny (0.1/0.4/0.005) fractal with low color contrast (0.2) and high color of 0.2. This kind of adds little specks to the main color variation. So it's all done in color space, not displacement. This color is set as input for displacement (2m), with offset of 1m.