Soil dissolved parent rock as a secondary mineral, except when derived from the weathering of mica. It is the surface area to volume ratio (specific surface area) of soil particles and the unbalanced ionic electric charges within those that determine their role in the fertility of soil, as measured by its cation exchange capacity. Sand is least active, having the least specific surface area, followed by silt; clay is the most active. Sand's greatest benefit to soil is that it resists compaction and increases soil porosity, although this property stands only for pure sand, not for sand mixed with smaller minerals
Godalming of the town centre steep hills reach 95 m (311.67 ft) AOD from 40-45m (131.23-147.63 ft) AOD in the town centre itself. In terms of rock and mineral structure, the soil is Gault Clay superimposed by Upper Greensand, Claygate Beds and Bagshot Sands; throughout the narrow east-west middle valley of Godalming and its wide northeast suburbs (Farncombe and Catteshall) the rocky head geological deposit is also found; angular pieces of rock and soil derived locally from the extensive frost-shattering of rocks and the subsequent movement of this material down valley slopes. Soil is mostly, i.e. on the upper slopes of