Tidal flat deposits occupy the low ground at Porlock, landward of which are river terraces and the modern day alluvial deposits associated with the Horner Water and its tributaries. Deposits of fragmentary rock material, the result of weathering and downslope movement of the underlying bedrock are known as ‘head' and are widely recorded within the valleys of the national park. A number of areas of peat are recorded on the upland surface of Exmoor. Small areas of talus (or scree) are found either side of Heddon Mouth. A variety of marine deposits are to be found along the shoreline including sand and cobbles whilst storm beach deposits are to be seen at Lynmouth.