Well-drained areas of the Coal Measures and Marros Group are characterised by poor soils supporting heather moorland.
The Marros Group is the new name that geologists give to the old Millstone Grit series – a suite of sandstones and mudstones which lie between the Coal Measures and the Carboniferous Limestone.
The heather moorland is in decline as a result of overgrazing and burning and is sometimes replaced by areas of species-poor grass moorland dominated by mat grass or purple-moor grass. These habitats extend to lower altitudes on the slopes of the Farewell Rock and Marros Group sandstones and mudstones.