It is composed of laminated mudstone and siltstone with greywacke sandstone and is of Ordovician age .
In common with much of the Northern Fells , the Kirk Stile Formation of the Skiddaw Group predominates .
Kirk Stile Formation is composed of laminated mudstone and siltstone with greywacke sandstone and is of Ordovician age .
In common with much of the Northern Fells , the Kirk Stile Formation of the Skiddaw Group predominates .