Rock uses the same texture as landscape. Then actual textures for rock are added on top of that using a world aligned blend node. Landscape texture is using a world aligned texture node for 3D projection in both landscape and rock.
Looks great, love the mood. Perhaps the rock looks too dark? Also, not a big difference in albedos between the floor vs the rock and the rock vs the brick...but hey, it could be a matter of taste hu? Keep up!