Above Sabden on the lower slopes of Pendle Hill is Deerstones a large frost affected area from the Ice Age. A number of detached blocks have shapes which were known locally as the 'Devil's footprints'. The shapes are sedimentary in origin rather than supernatural probably the fossil Calamites debris from a Carboniferous swamp. There are other examples within the area. (photo above) For full details see pages 29-30 "ghost, traditions & Legends of old Lancashire" Ken Howarth Sigma Press 1993. BGS Pendle Grit Member - Sandstone. Sedimentary Bedrock formed approximately 322 to 326 million years ago in the Carboniferous Period. Local environment previously dominated by sub-aqueous slopes.