The ages of soils worldwide

Some soils are very old. There are a few very old landscapes in the world which have not been greatly disturbed in recent geological time. These are mainly in the Southern Hemisphere, for example those of parts of Southern Africa. On these old surfaces soils have been able to develop over a long period of time relatively undisturbed, in some cases for many million years of years. The only interference to their development may have been local soil erosion and more recently farming.

Most soils of the world will have a younger history. As we have learned, the origin of many of the soils occurring in North America and Europe today date back to the time when the ice sheets melted some 10,000 years ago. They are thus relatively young compared to areas of the world where there are old surfaces. Most soils in Britain, for example, are less than 10,000 years old.

In some parts of the world it is even likely that soil formation will have to begin again today, for example where floodwaters have laid down new sediment, where sandstorms have deposited fresh sands, or where soils are being eroded. Soil formation is a continuing but often slow process. One thing that we can be sure of is that soil formation is going on all the time. Wherever there is a combination of factors such as parent material, climate, landscape and vegetation, soils will be forming or continuing to develop.