The Forest as described in this website is the area defined in red, the historic county of Northamptonshire is defined in black
Rockingham Forest lay between the Welland and Nene, which drain north eastward through the Fens and into the North Sea. Between the valleys is a plateau. On its north western edge is a scarp falling steeply into the Welland valley. In contrast, south eastward the whole plateau dips gently towards the river Nene. Over most of its area the plateau is capped by boulder clay, producing heavy and poorly drained soils, but in the north east there is no boulder clay and here an expanse of limestone created poor, thin and very dry soils. Both were marginal land, inhospitable for settlement and arable farming until transformed by modern drainage and chemical application. In the past the clay land was best used for woodland or for pasture while for a long period heathland covered much of the limestone area.
Simplified geology of the forest
In contrast, where the rivers and lesser streams have cut down through the plateau, they have exposed a very varied geology. Together with the gravels on the valley floor, these have provided fertile and well drained soils, ideal for agriculture and settlement. Only the lowest lying land in the valleys of the Nene and Welland could not be cultivated, because it was so often flooded, but for much of the last thousand years, until modern drainage schemes, these floodplains were highly valued as hay meadows.
Thus the pattern of the underlying geology and drainage has influenced the distribution of settlement and the character of the land use. But, because until recent times transport costs were so high, it also determined what building stone was available locally and where important industries such as iron production or stone slate manufacture could be established. In this way the geology has also affected the character of forest settlements and of the wider countryside as well as the local economy and much more.
The main physiographic zones of the Forest