Geology Site Account

Site name: Debden Water Gravel Pit

Grid reference: TL 5358 3399

Brief description of site:

Debden Water is now a small stream that runs into the River Cam at Newport. The great width of this valley was once filled with ice which produced torrents of meltwater depositing glacial gravel. A reasonable section through the gravel can be seen at the north end of this pit which is one of several disused gravel pits in this valley. Excavations have been carried out here by the British Geological Survey.

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Details

Whitaker et al. (1878) describes several pits here but it is not clear which is which. There are several pits along the valley, some are excavations for gravel and some for chalk. All are now overgrown with little gravel or chalk visible. This particular pit has the best visible exposure of gravel.

Lake and Wilson (1990) describes an excavation in the base of this pit which proved over 2.5 metres of gravels, soliflucted gravelly clays and chalk breccias, the base of which was not penetrated. An excavation in the southern face of the workings revealed a wall of shattered chalk, either in-situ or little moved, which defines the southern limit of the deposit. These gravels may be the exhumed relics of a formerly extensive deposit that filled the valley and was probably connected to the main buried channel complex at Newport.

The pit is on private land but the uncultivated land alongside the stream is largely public open space. The pit is next to the public footpath. It is adjacent to but not part of the Debden Water biological Site of Special Scientific Interest (SSSI).

Wicken Water Gravel Pit. Photo: G.Lucy