The Pickwell Down Sandstones are red and brown sandstones with shales which extend from the hills of Pickwell Down and Woolacombe Down overlooking Morte Bay east-southeastwards to Muddiford and Bratton Fleming. The outcrop pattern is shaped by a major east-west aligned syncline/anticline pair between Brayford, where there is a stone quarry, and Dulverton. East of Dulverton the formation forms the prominent Haddon Hill and extends via Heydon Hill as far east as the village of Wiveliscombe. There are a number of former workings for iron, copper and manganese across the western part of its outcrop. A geomorphological survey at Anstey's Coombe showed that mining had taken place at the site during both the Romano-British period and the 16th to 17th century.