Soil can vary enormously. Soil characteristics can
change across the landscape and also with depth. The soil under your feet
will be quite different from that just 40cm deeper. The above picture shows
the vertical changes in a soil profile that has developed on the flood
plain of a river valley. The dark band below the surface is rich in organic
matter while the pale zone below is due to the accumulation of lime
(calcium carbonate) by water percolating through the soil. Note the
presence of gravels deposited by the river at the base of the profile (EM).