A distinct layer of weak, easily broken shale or mudstone that forms the immediate roof over a coal seam. Because it lacks structural integrity, ramble tends to fall away as soon as the underlying coal is extracted. This creates a significant hazard for underground miners and requires immediate, heavy timbering or bolting to secure the roof.
Heard on the job
Watch your head in the new panel, there's a thick layer of ramble that wants to come down with the coal.