The soils are derived from the underlying rock almost exclusively and are acidic, stony, shallow and deficient in nitrates, phosphates and lime giving a low level of fertility. On the hillsides the soil depth is very shallow and in fact the 35 degree slopes often show patches of "soil creep" where gravity is causing the earth to break up and move down hill. The so called "sheep scrapes" are areas of broken bank where grass roots have been unable to hold the soil in place. If the break in the bank is large enough the sheep will take advantage to use the area to shelter from sun or wind. By constantly moving in and out of a patch and by rubbing themselves against the bank they then cause further erosion. In many places the earth has worn off to reveal the wonderful rock structures beneath, much to the advantage of geologists!
Soils in the area have been mapped by Mackney and Burnham (1966). There are three main complexes on the Trust property. There is a complex of peaty podzols and peaty gleyed podzols on the gently undulating ground of the head covered plateau. In the areas of the hill where the wetter mire conditions prevail a complex is dominated by peaty gley soils. On the steep valley slopes and a few summit areas, the soils are of the Batch Complex: brown earths and brown podzolics, which are freely drained and acidic.