The River Mole: Landscape, Geology & Topography

Along the Mole Gap Trail…

Rising in Sussex and flowing into The Thames

You are standing on the chalk ridge that runs east-west to form the North Downs. The porous nature of the chalk results in very little surface drainage. Dry valleys cut by rainwater but devoid of permanent, surface streams are a feature of this type of landscape. The River Mole, because it rises in the clay Weald and only flows over a narrow belt of chalk, has been able to cut a channel on its way to the Thames. However, significant qualities of the Mole’s water disappears underground into the chalk bedrock via ‘swallow holes’.

The origin of the river’s name is unclear but its medieval name of Emlyn and the modern name of Mole are likely to derive from its disappearance beneath the chalk at Mickleham. Edmund Spencer, writing his poem ‘The Faerie Queene’ at the end of the 16th Century writes: ‘And Mole, that like a nousling mole doth make, His way still under ground till Thames he o’ertake’.