CGside shows how to make a cliff in Maya Bifrost, which includes working with volumes.

Check out this tutorial that uses Autodesk Maya Bifrost to procedurally create a cliff, including working with volumes, meshing, and scattering vegetation.

The tutorial host, CGside uses Envit, the Maya scattering script that uses Bifrost in the backend.

A while back, Simon Verstraete shows a more elaborate method for creating cliff faces with Side FX Houdini that is similar in process. Check out that tutorial here.